Upload
doankhuong
View
216
Download
2
Embed Size (px)
Citation preview
A Comprehensive Approach to Assessing the Tourism
Potential of Geological Sites in a Natural Area Tourism
Destination: Rottnest Island as a Case Study
By
Jessica Rutherford
This thesis is presented for the fulfilment of the requirements for the Master’s degree in Environmental Science, at Murdoch University
Submitted November 2012
ii
Declaration
I declare that this information within this thesis is the result of my own research, unless
cited otherwise, and the content of its work has not been previously submitted for a
degree at any other tertiary educational institution.
XJessica Rutherford
iii
Acknowledgements
I would like to thank the people and organisations who have contributed to the process
and completion of this thesis. A special thanks is given to the following people.
Rottnest Island Authority, for funding the research, and in particular Teagan Goolmeer,
Rebecca Chaffer, Nathan Squires and David Robertson for the use of their time and
resources during field studies.
Bob Gozzard from the Geological Survey of WA, for the use of his time, invaluable
expertise and knowledge.
Dr David Newsome and Dr Halina Kobryn, my Murdoch University supervisors for their
tireless support, encouragement and guidance throughout this research.
Dr Audrey Dallimore, with Royal Roads University, her encouragement and direction in
embarking on this research journey.
Ross Lantzke from Murdoch University for expertise on GIS and his enthusiastic
technical and artistic support.
Lastly, a special thank you to Ray Dickson, Jenny Rutherford and my husband Dan
Rutherford for their field assistance, editing and formatting expertise, and unconditional
moral support and encouragement.
iv
Abstract
Geotourism is an emerging form of sustainable natural area tourism which provides
tourist access to and interpretation of the earth’s geological features and processes. Its
focus on the conservation of significant geological features provides the means to
generate educational, environmental and economic benefits. The significant growth in
geotourism globally over the past decade has created a demand for more robust and
systematic approaches to assessing the geotourism potential of natural areas, and
identifying suitable sites of geological interest (geosites) that meet economic and
environmental demands.
With the emphasis on tourism opportunities that provide access to and interpretation of
geosites, this research proposes a powerful approach that incorporates a Geographical
Information Systems (GIS) method for identifying suitable field geosites in a geologically
rich natural-area tourism destination. This was achieved by reviewing relevant literature
and existing environmental GIS datasets, in association with field studies, to identify
significant geological features and processes, with a view to identifying suitable geosite
locations for interpretative geotourism products on Rottnest Island, Western Australia.
In particular, this research investigated the geotourism opportunities on Rottnest Island,
by assessing geosites based on criteria of geological representativeness, tourism access
and management considerations using a Multi-Criteria Evaluation (MCE) method within
GIS processing software.
v
This study has confirmed that Rottnest Island has sites with geotourism potential and
that GIS, combined with field studies, is a beneficial component to geotourism planning
and identifying potential geosites. Specifically, in the context of geotourism planning
and management, this research highlights critical topics associated with generic criteria
for selection of geosites, the importance of access in geological tourism, the utility of GIS
in geotourism planning and the need for geo-interpretative themes for the development
of geotourism on Rottnest Island.
Results of this research generated a spatial database containing information on the
geology, tourism access and management considerations for 63 field geosites on
Rottnest Island. Particularly the results of GIS data queries revealed a number of sites
suitable for easy, moderate and advanced tourism access. Furthermore, this research
provides a guide to the prominent data that can support geotourism product planning
and to site specific information regarding geoconservation through environmental
management strategies.
vi
TABLE OF CONTENTS
Chapter 1: Background ............................................................................... 1
Geotourism: Niche tourism ............................................................................................... 1
Applications of GIS in geotourism ..................................................................................... 4
Rottnest Island study area: A profile................................................................................ 5
Geographical setting .................................................................................................. 6
Tourism profile ........................................................................................................... 6
Rottnest Island’s geotourism potential ..................................................................... 7
Aims of the project ............................................................................................................ 8
Chapter 2: Methods .................................................................................. 10
Desktop review ............................................................................................................... 12
Geology of Rottnest Island ...................................................................................... 12
Review of GIS data sets ............................................................................................ 12
Tourism access profile and the determination of tourism access categories ......... 13
Field investigation ........................................................................................................... 14
GIS analysis ...................................................................................................................... 17
Field data collation and data analysis ...................................................................... 18
Field data analysis .................................................................................................... 20
Data exploration and queries for geology and access ............................................. 20
Identification of potential sites of geological interest............................................. 23
Chapter 3: Results ..................................................................................... 27
Generic criteria identified via desktop review ................................................................ 28
Geological representativeness on Rottnest Island ......................................................... 30
Results of field investigation ........................................................................................... 34
Results of GIS Analysis ..................................................................................................... 39
Compilation of field data ......................................................................................... 39
Utility of GIS for identifying potential areas of geological interest ......................... 43
Chapter 4: Discussion ................................................................................ 49
Primary criteria in the selection of sites for geotourism ................................................ 49
Access in context of geotourism ..................................................................................... 51
Applications and limitations of GIS in geosites identification ........................................ 52
Geotourism opportunities for Rottnest Island according to geological themes ............ 55
Chapter 5 Conclusion ............................................................................... 57
References………………………………………………………………………………………………..59
Appendices ................................................................................................. 65
vii
LIST OF FIGURES Figure 1: Rottnest Island study area, 18 km off the Western Australia coast, with
insert showing sub-marine ridges inicating previous shorelines. ........................ 3
Figure 2: A conceptual model of primary criteria for the development of suitable sites of geological interest. ......................................................................................... 16
Figure 3: Field data analysis processing flow chart........................................................... 19
Figure 4: Flow chart for the MCE potential areas analysis. .............................................. 24
Figure 5: Well-defined eolian cross-bedding in the Tamala Limestone at Jennies Lookout and intertidal platforms cut into softer limestone (insert image). ...... 31
Figure 6: Distinct in situ solution channels embedded amongst the honeycomb weathered limestone with calcified rhizoliths structures, at Little Salmon Bay. ...................................................................................................................... 32
Figure 7: A selection of photographs from various locations on Rottnest Island showing the range of geology and coastal geomorphology available for geotourism opportunities. .................................................................................. 33
Figure 8: Field investigation results showing 63 field geosites on Rottnest Island. ......... 36
Figure 9: A selection of the key geological features found around the inland lake system on Rottnest Island. .................................................................................. 38
Figure 10: Spatial location of field geosites for each tourism access category, easy, moderate and advanced. .................................................................................... 40
Figure 11: Visual representation of delineating bare areas (potential locations for geosites) and overlaying specific criteria pertaining to geology, access infrastructure and management constraints (e.g. hazards). .............................. 44
Figure 12: MCE analysis results showing the comparison of designating a hazard raster image as a constraint (top image) and removing hazards from constraints (bottom image). MCE with hazards layer produces specific locations within bare areas and MCE without hazards layer delineates large zones for potential sites. ..................................................................................... 46
Figure 13: Potential locations in bare areas (top image) and field geosites overlayed with potential sites, showing the results of MCE for identifying potential sites of geological interest. ......................................................................................... 47
viii
LIST OF TABLES
Table 1: Summary of GIS data sets incorporated in the project. ...................................... 11
Table 2: Description and specification for Three tourism access categories, the description and examples of geosites on Rottnest Island. ................................. 14
Table 3: Examples of data queries used to determine specific information pertaining to field sites ......................................................................................................... 21
Table 4: Data layers pertaining to constraints and factors for four MCE trials. ............... 26
Table 5: Essential factors associated with the geosite suitability criteria, geology, access and management. .................................................................................... 28
Table 6: Field geosite examples on Rottnest Island for each tourism access category. .. 29
Table 7: geological interpretative themes on Rottnest Island derived from a review of the literature. ...................................................................................................... 35
Table 8: Summary of results generated from data queries performed on 63 field geosites, showing the number of sites per access category and the number of the sites with high management concerns and specific geological features. 42
Table 9: Comparison of hazard assessment at geosites using data collected in this study and existing site hazard assessments (Syrinx 2010b). .............................. 43
1
CHAPTER 1: BACKGROUND
GEOTOURISM: NICHE TOURISM
Geotourism, a niche form of ecotourism, aims to provide opportunities for visitors to
view and experience geological and geomorphological processes in a way that
generates appreciation and understanding of the environment (Hose 2005; Vujicic et
al. 2011; Hose 2012a). In particular, geotourism is founded on providing access to the
interpretation of the geological features and processes (e.g. mechanisms of
weathering, erosion and tectonics) of a natural area (Dowling and Newsome 2010). It
also has the means to generate awareness of and economic benefits to tourism
destinations and communities. Newsome and Dowling (2010) additionally describe it
as the context and means to incorporate geological scientific data into accessible and
engaging information, in order to generate public interest, by means of accompanying
nature-based tourism products placed in suitable locations. The main elements of their
work emphasise the recognition and identification of geosites (sites of geological
interest) and the importance of interpretation via pamphlets, information panels, self-
guided trails and guided tours (Dowling and Newsome 2010).
With its roots founded in the United Kingdom and its subsequent recognized
emergence in the late 20th Century, geotourism has grown into its own distinct form of
geologically based tourism (Hose 2012a; Thomas 2012). An illustration of this growth is
summarized in Newsome, Dowling and Leung (2012), who provided a list of some
2
important geotourism products that have emerged since the year 2000. The global
geopark concept, which was initiated in Europe, has expanded internationally, over the
last ten years, and China is recognized as a global leader in embracing the geopark
model, with the creation of over 200 geoparks in the country (Fung and Newsome
2010; Hose 2012a; Newsome et al. 2012). The geopark concept has yet to be fully
realized in Australia, however geological tourism destinations like Uluru (Ayers Rock) in
Central Australia have operated for over 100 years and new geotourism products have
been developed through the creation of the Kanawinka geopark in eastern Australia
(Lewis 2010).
Geotourism and geoheritage in Australia, according to Joyce (2010) have emerged
through the innovative work of the Geological Survey of Australia (GSA), which has
established an inventory of proposed geoheritage and geotourism locations around the
country. This work has led to an increase in the number of opportunities for geological
tourism. Some opportunities listed in Joyce (2010) include fossil reserves in Lake Eyre,
South Australia, Undara Crater and lava tubes in Queensland, and the limestone pillars
of Nambung National Park, Western Australia (Newsome and Dowling 2006).
The established tourist destination of Rottnest Island, Western Australia (Figure 1), was
selected for investigation regarding its geotourism potential, as both previous research
and the Rottnest Island Authority (RIA) have recognized opportunities to advance
geotourism on the island (RIA 2009; Palmer and Newsome 2010; RIA 2011). At present
the geotourism attractions of Rottnest Island are underutilized.
3
FIGURE 1: ROTTNEST ISLAND STUDY AREA, 18 KM OFF THE WESTERN AUSTRALIA COAST, WITH INSERT SHOWING SUB-MARINE RIDGES INICATING PREVIOUS SHORELINES.
Rottnest Island
4
With the emphasis on tourism opportunities that provide access to and interpretation
of geosites, this thesis proposes a novel approach that incorporates a Geographical
Information Systems (GIS) method for identifying suitable field geosites in a
geologically rich natural-area tourism destination. In this study, the iconic Western
Australian tourism destination of Rottnest Island (Figure 1) was investigated for its
geotourism potential. This was achieved by reviewing relevant literature and existing
environmental GIS datasets, in association with field studies. The aim was to identify
significant geological features and processes, with a view to identifying suitable geosite
locations for the development of interpretative geotourism products on Rottnest
Island.
APPLICATIONS OF GIS IN GEOTOURISM
Geographical Information System (GIS) analysis of spatial data is a specialized set of
tools, which can be used to analyse complex questions on the allocation and evaluation
of specific criteria for areas of potential tourism interest (Johnston 1998; Eastman
2012). This research proposes an approach using components of GIS environmental
datasets and aerial and satellite imagery, in conjunction with field site investigation for
the assessment of geological sites of potential tourist interest on Rottnest Island. The
use of GIS in tourism management and as a planning tool is increasing, and some
studies have incorporated components of GIS, within the context of Environmental
Impact Assessments (EIA) and inventories of land-use, for identifying suitable
geoheritage and ecotourism hotspots. For example, Vujicic et al. (2011), have
5
conducted research on the Fruska Gora Mountains of Serbia, and proposed a geosite
assessment model for identifying potential geotourism destinations. This approach
combines components of environmental impact assessments and land-use inventory
evaluation, and which is based on the scientific/educational/scenic value and the
tourism functional ability. Furthermore, Gavrila et al. (2011) created a GIS dataset and
topographical digital map of the most representative geomorphological sites for the
assessment of the geoheritage in the Macin Mountains of Romania. Schutte and
Booysen (2010) linked GPS locations of geosites to an 1:500 000 scale environmental
map of Kruger National Park, South Africa. However, little research has been done,
using existing environmental GIS datasets, to develop a system of identifying and
evaluating geosites with the focus on representative geology, tourism access and
specific management considerations.
ROTTNEST ISLAND STUDY AREA: A PROFILE
Rottnest Island (Figure 1) is an east-west trending island located approximately 18 km
west of Fremantle, Western Australia, and contains geological, biophysical, cultural and
wildlife resources (Playford 1988; Brooke et al. 2010; Palmer and Newsome 2010). It
holds iconic local, national and international tourism status for Australia. The island is
11 km long, 4.5 km wide, with a total land area of 1900 hectares (RIA, 2009). The island
has a Mediterranean climate with dry summers and wet winters (Playford 1988). The
marine environment component of the reserve covers approximately 4000 hectares
and extends 800 m from the shoreline (Figure 1).
6
GEOGRAPHICAL SETTING
The island is a coastal quaternary carbonate eolian dune complex that is located in the
tectonically stable region within latitude 32o S, on the continental shelf off the coast of
Western Australia (Szabo 1978; Playford 1997; Vacher and Quinn 2004; Brooke et al.
2010). Rottnest Island exhibits classic carbonate island features (Vacher and Quinn
2004), comprising of fresh water lenses (water located beneath limestone), undulating
dune topography and eolian cross-bedded cliffs that often contain fossilized marine
deposits, paleosols, rhizoliths and solution channels (Playford 1988, 1997; Vacher and
Quinn 2004). Marine bathymetry shows a late Quaternary history of dune systems,
parallel ridges, reefs and evidence of previous shorelines (Richardson et al. 2005).
Further geological features are described in Appendix 1.
There are 36 km of calcarenite coastline, composed of 63 sandy beaches dispersed
between 20 bays, separated by rocky headlands and intertidal platforms that cut into
the late Pleistocene and early Holocene eolian dunes (Playford 1997; Short 2005;
Gozzard 2011).
TOURISM PROFILE
Rottnest Island has functioned as a tourism destination since the 1900s, while still
operating as a prison facility for Aboriginal men until 1930. It was recognized as an A-
class nature reserve (conservation of Crown land protected under legislation) for
tourism in 1997 under the Land Management Act 1997 (Playford 1988; RIA 2009).
Today the island attracts approximately 560,000 visitors annually with 48% of these
being repeat visitors (RIA 2011). Of these visitors, 70% are from Western Australia, 15%
7
from interstate and 16% from overseas, highlighting its attractiveness as a local holiday
destination (RIA 2009, 2011). The majority of the visitors arrive by commercial boats
and private air charters. However, over time there has been an increase in visitors
arriving by alternative transport. For example, in 2011, 33% of the annual visitors
arrived by private boat (RIA 2011). There are three Settlements located at the eastern
end of the island, offering accommodation, service facilities and the port of entry to
the island at Thompson Bay. The remainder of the island is only accessible by foot,
bicycle or the island bus service. With the exception of the RIA service vehicles, no
other private vehicles are allowed on the island.
The island offers an array of recreational activities, the majority of which involve
marine activities, including boating, fishing, surfing, swimming, snorkelling and diving
(Richardson et al. 2005; Smallwood et al. 2006). Additionally, walking, cycling, golfing,
and bird and wildlife touring are popular activities. There is one eco-boat tour operator
that provides visitors with two daily tours during the summer season. This tour offers
visitors the opportunity to view marine wildlife, however, it provides limited
explanation of the island’s geological features (Palmer and Newsome 2010).
ROTTNEST ISLAND’S GEOTOURISM POTENTIAL
Rottnest Island’s unique carbonate geologic features (stromatolites, evidence of sea
level change, exposures of Late Pleistocene eolionite and Holocene dunes) (Playford
1988) present examples of geological phenomena, particularly relating to global
climate change, and offer opportunities for the development of geotourism, where the
8
focus of tourism is on their particular features. Given that Rottnest Island contains
world class geological features, its geotourism profile can be realized by expanding an
existing environmental geologic GIS database, with the aim of raising the geosciences
literacy of both the public and tourism managers (Brocx 2008; Palmer and Newsome
2010). According to geotourism researchers (e.g. Dowling and Newsome 2006; Dowling
2010; Hose 2012) it is essential Rottnest Island management provide sustainable,
unobtrusive and educational geological interpretation that can enhance the island’s
tourism economic and environmental conservation needs (Palmer and Newsome
2010).
Previous research by Palmer & Newsome (2010), acknowledged that there is a lack of
geological interpretive information along tourist routes on the island, and that Rottnest
Island Authority (RIA) would benefit from further research of the tourism potential of
the island’s geologic features. The Rottnest Island management plan for 2009-2014,
encourages the development and creation of new sustainable and educational tourism
opportunities that will generate renewed interest in the island (RIA 2009). Under the
Tourism and Recreation Strategy section of the management plan, investing in
geotourism research is strongly supported.
AIMS OF THE PROJECT
The aim of this thesis therefore is to apply a systematic approach to identifying suitable
geosites for geotourism planning. Furthermore, by utilizing components of GIS analysis
tools within the computer software programs of ArcGIS and IDRISI Selva, this project
9
aims to apply a multi-criteria evaluation (MCE) method for the identification of
potential sites of geological interest (Eastman 2012). The project also investigates
suitable geosites for the subsequent development of interpretive content for
geotourism products such as, interpretive panels, pamphlets, guided tours and mobile
phone applications. Associated with these project aims are four research questions:
1. Does Rottnest Island have suitable sites of geological interest for the delivery
of specific geo-interpretation content?
2. Can the existing environmental GIS data sets (RIA 2010; Syrinx 2010b;
Gozzard 2011; Syrinx 2012) be used to determine potential areas of geological
interest, based on geological attributes, tourism access and management
constraints?
3. Can the environmental geology GIS database (Syrinx 2010b; Gozzard 2011;
Syrinx 2012) be used to address issues of visitor access and safety?
4. Is it possible using the 2 and 3 above to recommend specific geosites that can
be readily accessed and viewed by the visitors to Rottnest Island?
This research builds on previous work by Playford (1988), Palmer & Newsome (2010),
Syrinx Environmental (2010a) and Gozzard (2011), with the aim of providing
comprehensive geological information for Rottnest Island managers, policy makers and
visitors. An overall objective is that the methodology established through this research
will provide future researchers and tourism managers with a systematic assessment
method and tools which will assist in developing geotourism opportunities in natural
areas elsewhere.
10
CHAPTER 2: METHODS
Addressing the research questions of this study and assessing the geotourism potential
of Rottnest Island, involved three components:
1) A desktop review on literature pertaining to geotourism, geology of Rottnest
Island and tourism access criteria,
2) Field investigation on Rottnest Island with a view to identifying sites of
geological interest,
3) Analysis of existing environmental GIS data sets to determine the potential
location of geosites and to assess the utility of a standard GIS method in making
such determinations on Rottnest Island.
Existing environmental GIS data (Table 1) sets were combined with field data to assess
criteria for geosite suitability, based on geological representativeness and tourism
access. The GIS datasets, aerial photography and satellite imagery, combined with data
collected in this research, were used to generate a geological GIS data set of field
geosites on Rottnest Island. Geographic Information System (GIS) analysis tools in the
computer software ArcGIS 10.0 and 9.3 were used to evaluate and geographically
represent potential sites for geotourism. The Multi-Criteria Evaluation computer
program in IDRISI Selva 17.0 provided geoprocessing tools necessary to investigate the
utility of GIS-based models for assessing the suitability of geosites in a natural area
tourism destination.
11
TABLE 1: SUMMARY OF GIS DATA SETS INCORPORATED IN THE PROJECT.
DATA TYPE LAYER NAME DATA FORMAT DESCRIPTION SOURCE RELEVANCE TO PROJECT
Field data
RI Geosites GDA94 MGA50 Vector point, excel spreadsheet
Location and attribute description for 63 field geosites This project Data collation, overlayed with potential sites map created in IDRISI MCE potential sites analysis
Imagery Multispectral image Raster QuickBird 4 band satellite image of Rottnest Island, 2.4m pixel resolution
(RIA 2010) MCE potential sites analysis
Aerial photograph image ECW 3 Band Raster May 2010 aerial photography of Rottnest Island, at 0.1m pixel resolution
(RIA 2010) Field investigation; MCE potential sites analysis
Aerial photographs Photos linked to vector point
Location of aerial photographs identified and linked to image filename and associated bays and beaches
(Gozzard 2011) Field investigation, data collation
Geology Surficial geology Vector polygon Location and surface geology material (limestone/limesand, clay, beach sand, calcareous silt, coquinite, water and man-made surfaces)
(Gozzard 2011) MCE potential sites analysis, data collation -intersect with Field data
Coastal geomorphology Vector polygon Location and narrative of geomorphology and landform type (Gozzard 2011) MCE potential sites analysis, data collation -intersect with field data layer
WA coastline Vector line Tidally-defined zones differentiated by bedrock, rock platforms, perched or reflective beaches, storm benches and rocky groynes
(Gozzard 2011) MCE potential sites analysis, data collation
Coastal sensitivity Vector line Location & type of susceptibility to coastal processes (weathering & erosion). Layers differentiated by hard rock coastal cliffs, sandy shorelines rock or sediment backed & hard rocky shores.
(Gozzard 2011) MCE potential sites analysis, data collation
Beaches (Short) Vector line Classification of beach and rocky coastline features determine by Andrew Short, University of Sydney (Short, 2006)
(Gozzard 2011) Data collation-multiple ring buffer, data query
Beaches Vector point Location and classification of beach type (Gozzard 2011) MCE potential sites analysis, Field investigation, data collation –ArcGIS multiple ring buffer, data query
Marine reserve Vector polygon Location of marine reserve boundary (Gozzard 2011) Overlayed with QuickBird Rotto image to indicate marine reserve boundary
Environmental geology map ECW 3 Band Raster Australia environmental geology map series, scale 1:50k (Gozzard 2011) Data collation and cross-reference geology classification to field geosites
Topography 2m contours Vector line Surface contours at 2m intervals derived from digital elevation. (Gozzard 2010) Field investigation, MCE potential sites analysis
Digital elevation model Raster DEM resample to 2m resolution (RIA 2010) MCE potential sites analysis
Infrastructure Buildings Vector line Location of building and the Settlement area (RIA 2010) MCE potential sites analysis, data collation –ArcGIS multiple ring buffer, data query
Bus stops Vector point Locations of the Bayseeker bus stops (RIA 2010) Field investigation, MCE potential sites analysis, data collation -ArcGIS multiple ring buffer, data query
Sealed roads Vector line Location of all paved roads (RIA 2010) Field investigation, MCE potential sites analysis, data collation -ArcGIS multiple ring buffer, data query
Unsealed roads Vector line Location of all unpaved roads (RIA 2010) MCE potential sites analysis, data collation -ArcGIS multiple ring buffer, data query
Tracks & firebreaks Vector line Location of all dirt tracks and firebreaks (RIA 2010) MCE potential sites analysis, data collation -ArcGIS multiple ring buffer, data query
RIA Coastal walk trail Vector line Approximate width, length and surfaces of the proposed RIA CWT trail
(Syrinx 2010b) Field investigation, data collation -ArcGIS multiple ring buffer, data query
Management RIA geological hazard & risk Vector point Location & consequences of coastal hazard and geological risk: Assessment report by Gordon (2007)
(Syrinx 2010b) Potential sites analysis via IDRIS MCE. Modified classification to only three hazard categories (High, Moderate, Low)
12
DESKTOP REVIEW
GEOLOGY OF ROTTNEST ISLAND
The review of the geology of Rottnest Island is contained in Appendix 1, and this
provides the context and planning framework for the field investigations. In particular,
information gained in the literature review provides data for the development of
geological themes and criteria utilized in the GIS analysis for geosite suitability. This
information gained in the literature review also provided the site evaluation content
for the data collection table used in the field investigation. The evaluation criteria
detailed in the data collection table (Appendix 2) incorporated concepts from several
key publications addressing methods and factors used in evaluating sites of geological
interest (e.g. Pralong 2005; Brocx and Semeniuk 2007; Pereira et al. 2007; Pereira and
Pereira 2010; Vujicic et al. 2011).
REVIEW OF GIS DATA SETS
Three environmental GIS data sets were used in this study (Table 1). GIS data sets
provided the spatial content and context for the field investigation, and were used to
identify potential locations of geological interest using the computer based MCE
decision support tools (ArcGIS 2012b; Eastman 2012). The MCE method was used to
determine suitable site locations, where the decision between alternative were based
on geology representativeness, tourism access and environmental management
criteria for the geosite. The data files, their description and relevance to this project’s
field investigation, project data collation and MCE analysis are summarized in Table 1.
13
TOURISM ACCESS PROFILE AND THE DETERMINATION OF TOURISM ACCESS CATEGORIES
The island environment of Rottnest Island generates a specific set of access factors.
This is due to the fact that the ability to experience the natural attributes of the island
is via three modes of transport; walking, cycling or via the island’s bus service. Tourists
have the choice to cycle and walk parts of the island along an internal network of
bitumen road that traverses the central part and coastline of the island, and visitors
can also access various points around the island using the island’s Bayseeker bus
service.
In addition, Rottnest Island Authority has recently commenced the construction of the
proposed RIA Coastal Walk Trail project, referred to in this thesis as the coastal walk
trail. The coastal walk trail is a comprehensive trail network that aims to offer visitors
greater exposure to the cultural, historical and natural features the island has to offer,
while minimizing informal access trails and environmental degradation (Syrinx 2010a;
RIA 2012b). The first stage of the coastal walk trail has been completed, and visitors
can explore the west end of the island via the interpretative signage trail at Cape
Vlamingh. The coastal walk trail GIS database (Syrinx 2010b, 2012) was incorporated in
this research in order to spatially assess geosite proximity to this proposed trail
network. Further information on the coastal walk trail can be found on the Rottnest
Island Authority website (RIA 2012b).
Infrastructure type data layers (Table 1) were incorporated into the models and utilized
for establishing access criteria based on Rottnest Island’s available modes of transport
14
and the tourism access categories created for this project (Table 2). These data files
(Table 1) were further used to classify field geosites, based on the three tourism
categories detailed in Table 2.
The tourism access profile generated for this project was created specifically to cater
for the Rottnest Island tourists. Therefore, establishing access categories was essential
for determining the accessibility of sites of geological interest in the field. In this study,
access suitability was based on three tourism categories: easy tourism access,
moderate and advanced (Table 2).
TABLE 2: DESCRIPTION AND SPECIFICATION FOR THREE TOURISM ACCESS CATEGORIES, THE DESCRIPTION AND
EXAMPLES OF GEOSITES ON ROTTNEST ISLAND.
Tourism Category Definition / Description
Easy Tourism Access
Access via public bus to the focal point of interest Requires walking ≤ 200m from the focal point (bus stop) to geosite on even surface
Moderate Tourism Access
Access via bus and/or bicycle and walking to focal point Requires walking 200m to 500m from focal point to geosite on any surface
Advanced Tourism Access
Access via bicycle and walking to the focal point Requires walking ≥ 500m from the focal point to geosite on any surface
FIELD INVESTIGATION
Locating geosites on Rottnest Island involved preliminary field visits, discussion with
experts (Bob Gozzard, WA Geology Survey) and consultation with RIA management.
Expert opinion was sought and applied in conjunction with a review of Playford’s
(1988) geology field guide of Rottnest Island and information gained from the desktop
15
analysis of and the existing geological/environmental GIS spatial datasets obtained
from RIA (2010; 2012), Syrinx Environmental (2010b) and Gozzard (2011).
Fifty-six potential locations were selected for field investigation and specific location
were refined using the aerial photographs at 0.1 m pixel resolution, obtained from the
data set of RIA (2010) and Gozzard (2011). Remote sensing imagery helped to eliminate
areas with limited or absent geological features and field access.
Previous research recognised that identifying attributes for geosites requires various
selection criteria (Pralong 2005; Reynard and Panizza 2005; Reynard 2008; Newsome
and Dowling 2010). Summarising the various selection criteria in this study, field
criteria were divided into three key categories based on geological representativeness,
tourism access and management considerations (Figure 2).
16
FIGURE 2: A CONCEPTUAL MODEL OF PRIMARY CRITERIA FOR THE DEVELOPMENT OF SUITABLE SITES OF
GEOLOGICAL INTEREST.
A data collection form (Appendix 2) was developed to facilitate a systemic approach to
inventory attributes of field geosites. This form outlines the parameters used to
differentiate between geological features which pertain to the geotourism themes, e.g.
sea-level rise, carbonate geology, and environmental change. The parameters were
applied in order to record specific information pertaining to each field geosite, which
were used in the data interrogations.
For the creation of a systematic field investigation and to utilize the island bus service,
the island was divided into three zones, the north and south sides of the island (north
and south zone), and inland lake region (central zone). A field identifying name was
given to each field site that corresponded to the zone and site number (e.g. CZ=central
zone) (Appendix 4).
Suitable Sites Of Geological Interest
Management
Geology Access
Visible & interpretable geology
Strategies to minimize adverse
impacts and hazards
Safe & accessible sites for various tourist
categories
17
Field investigations were conducted over 12 days, and involved walking, cycling and
using the island bus service, to survey potential sites identified in the desktop review.
Field sites were photographed and information regarding tourism access, management
factors (safety/hazards) and geological features were transcribed into the data
collection form (Appendix 2). Geosite coordinates were recorded using the Garmin GPS
Map 76 GPS) handset, using UTM WGS84 Zone 50 south. Specific data sets used in this
study are detailed in Table 1. Appendix 4 provides a summary of results of the field
investigation.
GIS ANALYSIS
The two main steps of GIS analysis used:
1) The collation and analysis of data obtained in the field investigation, to identify
suitable geosites for each tourism access category
2) The assessment regarding the utility of incorporating existing GIS data sets by
using Multi-Criteria Evaluations (MCE) to determine potential areas for sites of
geological interest
These two steps were conducted separately and the final results of both analyses were
intersected and combined in order to detect a correlation between the two
approaches. The information was used to generate a series of maps indicating the
spatial location of potential sites and suitable field geosites for each tourism access
category.
18
FIELD DATA COLLATION AND DATA ANALYSIS
Following the overall flow of data processing (Figure 3), the field collation and data
analysis addresses the geosite characteristics of geology representativeness, tourism
access and management constraints (e.g. sensitive habitat, hazards and safety).
Field data was entered into an Excel spreadsheet with the GPS location and field
attributes for each field geosite. The geosites field attribute table and corresponding
photographs were linked to the Excel spreadsheet which was then imported into the
ArcGIS 10.0. Adjustments were made on the geographical position of some geosite
point data, so as to minimize scale discrepancy between polygon layers on the surficial
geology and coastal geomorphology layers (Congalton and Green 2009).
19
FIGURE 3: FIELD DATA ANALYSIS PROCESSING FLOW CHART.
GIS data sets (Table 1) were spatially joined with the field data, providing
environmental and geological content for each geosite (Bolstad 2005; Eastman 2012).
For example, surficial geology and coastal geomorphology layers, as well as access
infrastructures (location of bus stops, roads and settlement) (Table 1) were intersected
to facilitate queries pertaining to proximity, environmental safety and geology features
for field geosites.
Data compilation
• Import into ArcGIS
• Data cleaning
Intersect data layers
• Surficial geology & coastal geomorphology
• Access date (roads, bus stops and settlement)
• Hazard data
Geosite proximity tourism access data
• Multiple Ring Buffers at interval of 100, 200, 500, 1000, 4000 & 8000 m
Geosite characteristics data
• Tourism categories
• Geology representativeness and theme
• Management factors (hazard data multiplied to field site)
Principal geosite selection database
• Field investigation geosites
• Geosite information to perform various data queries for tourism access & geology representativeness
20
FIELD DATA ANALYSIS
A set of multiple ring buffer distance files were generated using existing data files
pertaining to access infrastructure (Table 1) to provide distances (Figure 3) from the
geosites to the selected focal point feature (e.g. roads, bus stop, settlement).
Determining where sites were located in relation to their distance from the bus stop
was important because, in this study, the spatial locations of the existing bus stops
supplied by RIA (2010) were used as the focal points to the field geosites and were
used to classify site according to their accessibility for each tourism access category
(Table 2).
For sites of geological interest, spatial information used in intersecting data layers was
divided into three categories, which included geological representativeness, access and
management considerations (refer to Table 1 for data layers) (Pralong 2005; Hose
2006; Vujicic et al. 2011). The geoproccessing model, Hawth’s Tools in ArcGIS 9.31 was
chosen for its ease and convenience of intersecting multiple vector and raster layers at
once (ArcGIS 2012b). Database queries were conducted to assess the number of
suitable field sites for each tourism access category (e.g. easy, moderate and
advanced).
DATA EXPLORATION AND QUERIES FOR GEOLOGY AND ACCESS
Database explorations were carried out through performing various data queries, in
order to determine if field data corresponded with existing geology type layers (Table
1), and to evaluate proximity of the geosites to access infrastructure (roads, bus stops
and settlement). Data queries were also conducted to identify geosites that contained
21
a high hazard. Table 3 provides an example of data queries used to identify specific
information pertaining to field geosites. Access data were evaluated on the tourists
ability to access the geo-site based on the tourism category classification (Table 2). The
distance from the focal points (bus stops) to field geosites was queried using the
Multiple Ring Buffer layer (Table 1 and Figure 3). Geology type data queries helped in
determining the representative geological features of each field geosite using the
geology data layers summarized in Table 1 and field investigation data containing
specific geological features for each field site (e.g. presence of stromatolites, evidence
of sea-level change, eolian morphology, rhizoliths) .
TABLE 3: EXAMPLES OF DATA QUERIES USED TO DETERMINE SPECIFIC INFORMATION PERTAINING TO FIELD SITES
QUERY TYPE QUERY EXAMPLE OUTPUT
Access Categories (“Bus_stop” <200) AND (“Bus_stop” ≥500)
This query was used to identify the number of field sites per tourism access category
Geology & Geomorphology “Site_name” = geology features (e.g. Limestone, stromatolites, rhizoliths)
This query was used to identify specific geology surface type or feature, and geomorphological process
Management Constraints “Site_name” = management issue (e.g. high hazard, vegetation rehabilitation)
This query was used to identify sites with the highest hazards, and to determine specific management constraints
DATABASE QUERIES FOR MANAGEMENT CRITERIA
Literature shows that safe access to sites of geological interest is of utmost importance
and requires assessment focusing on sites that provide suitable safe access (Gunn
1988; Newsome et al. 2002; Drew et al. 2003; King 2010; Newsome et al. 2013).
Data interrogation pertaining to safety management issues focused on hazards
associated with the sites as a means of separating unsuitable field geosites. Initial
22
queries were conducted to identify the field geosites which contained some degree of
hazard, and further interrogations were conducted to cross reference field
investigation hazard data with existing hazard data from Syrinx Environmental (2010b).
The hazard data from Syrinx (2010b) was modified for this part of the research. The six
hazard categories were combined into three categories, e.g. low, moderate and high,
and the modified table imported into GIS. Each category was assigned a numeric value
and converted into a raster file, in order to easily interrogate areas with various hazard
categories (ArcGIS 2012a; Eastman 2012). A 100m buffer was generated around the
hazard locations in order to account for uncertainty in the geospatial location of the
hazard area (Congalton and Green 2009; Eastman 2012). The field geosite layer was
also imported into GIS as shapefile. It was estimated that the average size of the field
geosites were approximately 80 m (spatial extent of the geosite). This value was used
to create a buffer for the geosite raster layer.
In order to determine suitable geosites, a two-way comparison was conducted
between the field geosites hazard raster layer and the three modified Syrinx (2010)
hazard raster layers. This was accomplished by using Image Calculator to multiply each
100 m buffered hazard raster image with the 80 m buffered geosite raster image. This
generated three images showing where the field sites and the specific hazards
overlapped. A field site was deemed “not-suitable” if the site was flagged as a hazard in
three or more of the images.
23
IDENTIFICATION OF POTENTIAL SITES OF GEOLOGICAL INTEREST
Potential sites analysis was conducted with the aim of identifying potential areas of
geological interest, which could be further surveyed in the field for specific geological
features. This approach was incorporated into this study in an attempt to answer the
research question addressing the utility of GIS computer analysis models in identifying
potential areas of geological interest for geotourism.
For ease of analysis in this study, and to explore the MCE tools in standard GIS software
of IDRISI, four trials were conducted using different software, the MCE module and
MCE Decision Wizard (a method which compared a simple raster mathematical option
to a more sophisticated linear weighted mathematical expression, respectively) (ArcGIS
2012b; Eastman 2012).
Figure 4 demonstrates the goal and conceptual approach used in this analysis. Existing
data layers were imported into IDIRSI and converted to Raster images. Raster layers
were overlaid by multiplying image pixels to delineate specific locations (ArcGIS
2012b). In MCE, criteria required for most suitability evaluations are commonly divided
into factors, which indicate a relative suitability for an area and constraints which are
binary image expressions of yes or no (Clark Labs 2012; Eastman 2012). Data layers for
factors and constraints used in this MCE analysis (Table 1), included files on tourism
access (e.g. infrastructure data), geology representativeness (e.g. geology themes) and
management issues (e.g. hazards/risks) as detailed in Table 4.
24
PROCEDURE FOR IDENTIFYING POTENTIAL SITES
In order to identify areas potentially available as geosites, in this study it was firstly
assumed that they would need to have little or no vegetation, so that the geological
features can be readily viewed. In image processing, masking areas of no interest can
help to improve the results of analysis, and in this case masking out ocean water
bodies and vegetated areas was identified using a two-step masking process (Heywood
et al. 2002; Radiarta et al. 2008). In the first step an infrared band was used to create a
water mask. This is a very common approach (Lillesand et al. 2004; Eastman 2012) and
FIGURE 4: FLOW CHART FOR THE MCE POTENTIAL AREAS ANALYSIS.
Potential areas for geotourism on Rottnest
Island
Geology
Access Infrastructure
Management
CRITERIA/FACTORS THEME MODEL GOAL
Surface geology
Distance to settlement
Distance to paved road
Distance to bus stop
Geomorphology
High hazards & risk
Coastal sensitivity & erosion
Environmental sensitivity (bird nesting, dune erosion & revegetation areas)
25
takes advantage of nearly complete absorption of the NIR reflectance by the water. A
threshold of the absorption pixel value of 22 generated from a histogram showing the
pixels classified as water was used to create this mask. The second mask was for areas
of land which have vegetation cover. This was achieved through the process of a
supervised classification, where training sample of spectral signatures are created to
classify the land-cover image and represented as clusters of similar pixels (Eastman
2012). Clusters were validated against high resolution aerial imagery (Table 1) and
reclassed to create a vegetation mask which removed any pixels that were deemed as
vegetation, leaving only non-vegetation areas, referred in this thesis as bare areas
(Eastman 2012).
EQUAL WEIGHTED LINEAR COMBINATION MCE
As a first attempt and for a simple raster mathematical option for identifying
potentially available geosites, two trials using the MCE module were run. One with the
hazard layer as a constraint and the other without Table 4). This was done in order to
compare results between the two trails. Constraints, which are the factors that are
either a requirement (bare areas) or not a requirement (the water mask and high
hazard locations) were multiplied with standardized factor images (distance from bare
areas to bus stop, roads and buildings and geology in bare areas) of equal weighting,
creating an image of potential areas.
26
TABLE 4: DATA LAYERS PERTAINING TO CONSTRAINTS AND FACTORS FOR FOUR MCE TRIALS.
POTENTIAL SITE ANALYSIS
CONSTRAINTS FACTORS WEIGHTING
Hazard Constraint (MCE Module)
Water mask Bare areas Hazard 100m buffer
Bus stops raster >500m Buildings raster >4000m Sealed roads >500m Surface geology raster
factors= 1
No Hazard (MCE Module)
Water mask Bare areas
Bus stops raster >500m Buildings raster >4000m Sealed roads >500m Surface geology raster
factors = 1
Equal Weights (MCE Decision Wizard)
Water mask Bare areas
Bus stops raster >500m Buildings raster >4000m Sealed roads >500m ( All factor =FUZZY standardization)
Equal weighting
Non-Equal Weights (MCE Decision Wizard)
Water mask Bare areas
Bus stops raster >500m Buildings raster >4000m Sealed roads >500m ( All factor = FUZZY standardization)
None equal weighting (distance to bus stop with highest weight)
MCE DECISION WIZARD MODULE
The second approach involved using the MCE Decision Wizard, which allowed for a
simple classification of the constraints (0-1) and a complex standardised classification
(0-255) for the factors, which were reduced to a logical statement of suitability
(Lillesand et al. 2004; Eastman 2012). Using the Decision wizard allowed for more
flexibility by incorporating a fuzzy classification, which provides a greater range of
outputs and more variation in weighting factors (Clark Labs 2012; Eastman 2012). The
constraint images were multiplied with the same factors used in the first approach,
without using the hazard image to identify potential locations.
Weighting the criteria was limited to knowledge gained in this study and it is
recognized that expert consultation would provide a better representation of criteria
scoring. The locations of the potential sites identified through MCE were compared to
the field geosites.
27
CHAPTER 3: RESULTS
The results of this research, which incorporated a desktop review, field investigation
and GIS analysis for investigating the geotourism potential on Rottnest Island, revealed
three main findings:
1) There are generic criteria required for identifying the geotourism potential of a
natural tourism area that include geology, access and management factors;
2) Rottnest Island has significant geological features, and unique access and
management considerations that provide for suitable geosites for the
development of geotourism on the island; and
3) That existing environmental GIS data sets and GIS computer analysis tools can
inform and enhance the direction of field investigations for determining
potential sites of geological interest in a natural area.
The results of this research generated a comprehensive spatial database containing
information on the geology, access and management for 63 field geosites on Rottnest
Island. Specifically, the results of GIS data queries revealed a number of sites suitable
for easy, moderate and advanced tourism access (p. 30 Table 6). This geosite database
aims to facilitate in the development and implementation of geosites for geotourism
on the island. In particular, the geosites identified in this research could be
incorporated into the Rottnest Island Authority Coastal Walk Trail plan.
28
GENERIC CRITERIA IDENTIFIED VIA DESKTOP REVIEW
The results of the desktop review found that there are three key criteria required for
determining suitable locations of geological interest (geosites). These criteria include
geology, access and management factors that involve, respectively:
1) Assessing and identifying whether there are visible and interpretable geological
features and processes present in the natural area.
2) Reviewing current and proposed access infrastructure within the natural area
that will provide suitable access for various types of tourists, and
3) Identifying and evaluating management factors and constraints associated with
both the geological features and accessibility to the geosites.
Table 5 details factors associated with the geology, access and management criteria
that have been identified and utilised to assess the suitability of potential sites of
geological interest on Rottnest Island for the three tourism access categories (p. 30
Table 6).
TABLE 5: ESSENTIAL FACTORS ASSOCIATED WITH THE GEOSITE SUITABILITY CRITERIA, GEOLOGY, ACCESS AND
MANAGEMENT.
GEOLOGY FACTORS ACCESS FACTORS MANAGEMENT FACTORS
Visible geology
Interpretable geology and geomorphology
Longevity of the geological feature and the geosite o natural erosion of
geological feature o extent and impact of
environmental change (climate change, rising sea levels) longevity of the geological feature?
Current modes of travel (walking, bicycle, public or private vehicles)
Identify distance from a focal point (bus stop, road &/or settlement) to the geosite
Determine accessibility for various tourist types (tourism categories)
Tourism categories based on distance from a focal point
Management strategies (current & required) that include;
Hazard and risk associated with the geosite or access to geosite
Environmental sensitivities o sensitive habitat (e.g. bird
nesting grounds, rehabilitation areas, government protected areas)
Geological sensitivities o type and extent of erosion
29
The results of this research further revealed that safe access to a geosite is an
important criterion. A review of methods and standards for assessing tourism access
also indicate that in the context of geotourism and access to sites of geological interest,
there is little information on how to determine the accessibility of a geosite for various
tourist types. However this review did reveal that accessibility needs to be based on
the ability or willingness to travel to a site according to various tourist types and the
modes of access available to the tourist (Gunn 1988; Newsome et al. 2002; Drew et al.
2003; Arias et al. 2007; Jacobs et al. 2008; King 2010). Table 6 shows the specific
tourism access categories developed for this research, and provides examples of field
site location on Rottnest Island for each category; easy, moderate and advanced
tourism access.
TABLE 6: FIELD GEOSITE EXAMPLES ON ROTTNEST ISLAND FOR EACH TOURISM ACCESS CATEGORY.
TOURISM CATEGORY DESCRIPTION EXAMPLE ON ROTTNEST ISLAND
EASY TOURISM ACCESS
Access via public bus to the focal point of interest Requires walking ≤ 200m from the focal point (bus stop) to geosite on even surface
Geosite SZ_S9 Little Salmon Bay snorkel trail and beach site, showing extensive calcrete layer on limestone, rhizoliths, large solution channels and karst marine weathering
MODERATE TOURISM
ACCESS
Access via bus and/or bicycle and walking to focal point Requires walking 200m to 500m from focal point to geosite on any surface
Geosite CZ_S4 East end of the Causeway on the shores of Government House Lake, showing evidence of Sea level change (e.g. double notches, Herschell limestone shell deposits and fossil emu foot prints)
ADVANCED TOURISM
ACCESS
Access via bicycle and walking to the focal point Requires walking ≥ 500m from the focal point to geosite on any surface
Geosite SZ_S22 One Tree Hill (West End) Collapsed limestone cave, intertidal terraced platforms, no formal trail access and requires cycling to Radar Hill at the West End
30
GEOLOGICAL REPRESENTATIVENESS ON ROTTNEST ISLAND
A comprehensive outline of Rottnest Island’s geology and coastal geomorphology is
detailed in a literature review conducted for this project (refer to Appendix 1). The
following paragraphs are a summary of that review, highlighting the main geological
features found on Rottnest Island.
Rottnest Island is part of what is recognised as one of the world’s most extensive
Quaternary eolian limestone dune systems (Playford 1997; Brooke et al. 2010), and is
part of a chain of eolian dunes known as the Spearwood Dune complex that formed
some 140,000 to 130,000 years ago (Playford 1988; Hearty 2003; Hearty et al. 2007).
Marine bathymetry shows a late Quaternary history of dune systems, parallel ridges,
reefs and evidence of previous shorelines (Richardson et al. 2005). The islands
geological phenomena have played a significant role in the understanding global
Holocene and Pleistocene sea-level events (Fairbridge 1961; Playford 1988; Hearty
2003; Hearty and O'Leary 2008).
The island is composed of bays and beaches separated by rocky limestone cliffs that
back onto undulating active parabolic dunes (Playford 1997; Gozzard 2011). The
coastline is fringed by shallow marine platforms that cut into Pleistocene and Holocene
eolianite cross-bedded limestone known as Tamala Limestone (Figure 5). Tamala
Limestone consists of eolian sediments of the Spearwood dune complex, comprised of
quartz sand, marine fragments and fossilised root structures (Figure 6) (Playford 1988;
31
Hearty 2003). The island has an extensive system of saline lakes containing
stromatolites, algal mats and stratigraphy of marine mulluscan assemblages (eg.
Herschell Limestone). The elevated platforms, notches and visors in the Tamala
Limestone along the inland lakes provide evidence of Quaternary sea-level change.
FIGURE 5: WELL-DEFINED EOLIAN CROSS-BEDDING IN THE TAMALA LIMESTONE AT JENNIES LOOKOUT AND
INTERTIDAL PLATFORMS CUT INTO SOFTER LIMESTONE (INSERT IMAGE).
32
FIGURE 6: DISTINCT IN SITU SOLUTION CHANNELS EMBEDDED AMONGST THE HONEYCOMB WEATHERED
LIMESTONE WITH CALCIFIED RHIZOLITHS STRUCTURES, AT LITTLE SALMON BAY.
Rottnest Island thus contains an extensive array of classic carbonate features, and
according to the geoheritage “significance” grading system outlined in Brocx (2008),
geological attributes range from global to local significance. For example, the fossilised
corals found ~3m above the present high tide line (image D in Figure 7) and the
elevated shoreline feature around the inland lakes (image E in Figure 7), provide
evidence of sea-level change events of global relevance (Playford 1988). The extensive
limestone cliffs rich in marine assemblages and fossil root channels and the active
parabolic dunes terrain, are locally important because they explain the geological
processes occurring in that region (Brocx and Semeniuk 2007; Brocx 2008). Additional
images showing other geological features are indicated in Appendix 5.
33
FIGURE 7: A SELECTION OF PHOTOGRAPHS FROM VARIOUS LOCATIONS ON ROTTNEST ISLAND SHOWING THE
RANGE OF GEOLOGY AND COASTAL GEOMORPHOLOGY AVAILABLE FOR GEOTOURISM OPPORTUNITIES.
34
Furthermore, the results of this research identified that the geological features on
Rottnest Island provide evidence of major environmental changes, specifically in the
context of Quaternary sea-level change events. This information is useful for the
development of interpretative educational content for geotourism products.
Table 7 briefly draws attention to some geological interpretative themes that can be
introduced as the educational content for geotourism products on Rottnest Island.
Furthermore, Table 7 is a modification of the literature review contained in Appendix 1,
organising the key literature into the three main themes, i.e. sea-level change,
environmental change and historical conditions, and carbonate geology of the island.
35
TABLE 7: GEOLOGICAL INTERPRETATIVE THEMES ON ROTTNEST ISLAND DERIVED FROM A REVIEW OF THE
LITERATURE. Themes Sub Themes Global Significance References
Stories of sea-level change
Elevated fossil corals in eolian carbonate limestone
Elevation and age correlation to support global Holocene sea-level curve, surface and water temperature paleo-records
(Playford 1983, 1988; Kendrick et al. 1991; Wyrwoll et al. 1995; Playford 1997)
Shell beds & sediment stratigraphy
Historical geological processes of the earth and regional climatic indicators. Herschell Limestone and Rottnest Limestone
(Bailey 1977; Szabo 1978; Murray-Wallace and Kimber 1989; Backhouse 1993)
Rottnest Island’s connection to the mainland (bathymetry, fossil Emu foot prints, Aboriginal artefacts)
Evidence to support how to plan for future changes in the earth’s climate. Aboriginal occupation post separation from the mainland (~5.6ka).
(Playford 1988; Richardson et al. 2005; Brooke et al. 2010) (Bindon et al. 1978)
Elevated shore line platforms, notches and visor along the inland lakes
Historical global eustatic sea-level change information, planning for climate impact (development and geotourism)
(Fairbridge 1961; Playford and Leech 1977; Brooke 2001; Hearty 2003; Hearty et al. 2007; Brooke et al. 2010)
Environmental change and historical conditions
Stromatolites Early evidence of life on earth, oxygen production and present environmental change
(Grey et al. 1990; Geological Survey of Canada 2008; McNamara 2009; Hovland et al. 2010)
Salt lakes & swamp Connection to mainland; global Holocene sea-level correlations; collapsed cave systems; salt production and road building materials
(Playford and Leech 1977; Playford 1988; Backhouse 1993; Carew and Mylroie 1997; Vacher and Quinn 2004)
Modern corals & past coral assemblages
Climate Change & Ocean temperatures (Leeuwin Current)
(Szabo 1978; Church and White 2006; Spooner et al. 2011)
Carbonate-island geology
Eolian cross-bedding, marine shorelines (intertidal platforms, notches, visors and storm-benches
Coastal geomorphological processes in carbonate geology; knowledge for management planning and land use
(Playford 1988, 1997; Hearty 2003; Brooke et al. 2010; Gozzard 2011)
Origin of the Tamala Limestone sands
Complete illustration of carbonate sand and shoreline features and eolinate transport of sediments (Late Pleistocene and Holocene)
(Tapsell, Newsome et al. 2003; Hearty and O'Leary 2008),
Fossilised soils, calcified root structures (rhizoliths, solution-pipes) and calcrete layers
Paleo-records land processes and formations, historical vegetation coverage
(Playford 1988; Hearty 2003)
Tamala Limestone erosion, fragility and vulnerability
Risk assessment & management, planning for climate impacts, and the preservation of significant geologic regions
(Short 2005; Nageswara et al. 2008; Joyce 2010)
Fossil root channels (rhizoliths, solution-pipes)
Tuart forest –deforestation and reduction of atmospheric carbon dioxide
, changes to vegetation cover
(Storr 1963; Bowdler 1990; Playford 1997; Copp 2001; Church and White 2006; IPCC 2007; Greenstein and Pandolfi 2008)
36
RESULTS OF FIELD INVESTIGATION
Initial results of the desktop review identified 56 potential areas to survey, and a
further 7 sites were surveyed during field investigation. Field sites are distributed
throughout the island in the three regional zones (Figure 8), which incorporates the
inland lake system (central zone).
FIGURE 8: FIELD INVESTIGATION RESULTS SHOWING 63 FIELD GEOSITES ON ROTTNEST ISLAND.
Observations from the field investigation indicate that there are a number of locations
of geological interested that can be incorporated into interpretative geotourism
content for Rottnest Island. These field sites can be linked with the coastal walk trail,
providing the geo-interpretative content for geotourism opportunities. One area that
can be developed via the proposed coastal walk trial is the inland lake system. The
lakes contain an extensive array of geological features, particularly in relation to
Quaternary sea-level change events (Figure 9), and (the) access can be developed by
37
utilizing the existing spatial mapped location of the proposed coastal walk trail for the
lake system. Appendix 4 provides a summary of the specific geological attributes of the
63 field sites and a word document file with captioned photographs were created for
each of the 63 field geosites (not submitted with this thesis).
38
FIGURE 9: A SELECTION OF THE KEY GEOLOGICAL FEATURES FOUND AROUND THE INLAND LAKE SYSTEM ON ROTTNEST ISLAND.
Serpulid worm tube in Tamala limestone double -notches
Saltbush shoreline & walk trail
bush
Double Notches: Sea-level change
Coquina: Calcified shell deposits
Herschel Limestone shell stratigraphy: Sea-level change deposits
Pink Lake: microscopic algae Dunalella sailina
Rottnest Island Lakes
Moderate Access
Advanced Access RIA Proposed Lake Trail Road
Stromatolites
Government House Lakes
Serpentine Lakes
Herschel Lakes
Lakes Baghdad
Pink Lakes
Lakes Vincent
39
RESULTS OF GIS ANALYSIS
The analysis of geology layers help to formed direction for the field work and identify
access to the potential field sites. The MCE identified many potential locations were
less than 50 metres from field sites identified in the field investigation, and identified a
number of geosites suitable for each tourism access category.
COMPILATION OF FIELD DATA
Field data for the 63 field sites were combined with existing data layers, producing a
geosite database of sites of geological interested on Rottnest Island. Data queries were
conducted on the new geosite database file in order to gain information for access
suitability. Results of geology and access data queries revealed there are a number of
site per tourism access categories. Specifically, there are 12 easy, 19 moderate and 32
advanced tourism access sites (Figure 10).
40
FIGURE 10: SPATIAL LOCATION OF FIELD GEOSITES FOR EACH TOURISM ACCESS CATEGORY, EASY, MODERATE AND ADVANCED.
63 Field Geosites
Easy tourism access Moderate tourism access Advanced tourism access Settlement buildings Sealed roads
41
Initial investigations of the data considered the distance from bus stops and sealed
roads, based on the maximum distance for each tourism access category that
geotourists would have to travel to view the geological feature. Originally the
definition for the easy tourism category was assigned a distance to geosite of ≤ 100 m
from the bus stop; however, data query results found 7 sites with limited geology
available for the easy tourism option. Extending the distance from bus stop to a
maximum of ≤ 200 m generated 12 sites that provided a greater range of geological
features. However, there were limited geological features present in some of the easy
tourism access sites and these do not provide the complete range of geology available
on the island. This is indicative of the specified distance required to walk to the geosite,
as the access criteria is based on walking a specific distance from the bus stop (focal
point). As the deciding factor for each tourism access category is the distance from the
bus stop therefore, the greater the distance, the greater the opportunity for the tourist
to view more geological. Table 8 provides a summary of the results from various data
queries relating to tourism access, management considerations and available geology,
and Figure 10 shows the distribution of sites for each tourism access category.
42
TABLE 8: SUMMARY OF RESULTS GENERATED FROM DATA QUERIES PERFORMED ON 63 FIELD GEOSITES, SHOWING THE NUMBER OF SITES PER ACCESS CATEGORY AND
THE NUMBER OF THE SITES WITH HIGH MANAGEMENT CONCERNS AND SPECIFIC GEOLOGICAL FEATURES.
CRITERIA DATA QUERY & NUMBER OF SITES PER DATA QUERY COMMENTS
TOURISM ACCESS
* distance from bus stop & paved road
Easy (≤200m) * Moderate (200-500m) * Advanced (≥500m) * The number of sites are within distances from the focal point For details refer tourism access category table
12 sites 19 sites
31 sites (combined)
32 sites
45 site (combined sites, ≤1000m*) 63 sites (combined sites ≥5000m*)
MANAGEMENT (based on highest value)
Query factor # of Sites
Query factor # of Sites
Query factor # of Sites
** = moderate hazard
Data collected during field investigation
High hazard 4** High hazard 9** High hazard 6
Environmental sensitivity 0
Environmental sensitivity
3 Environmental sensitivity
2
Human vulnerability 1 Human vulnerability 0 Human Vulnerability 2
Erosion vulnerability 0 Erosion vulnerability 4 Erosion Vulnerability 6
Lakes 1 Lakes 3 Lakes 11
GEOLOGY (presence/absence)
Stromatolites 0 Stromatolites 1 Stromatolites 3 Geology data collected during field investigation
Fossil coral 0 Fossil coral 0 Fossil coral 1
Sea-level change 0 Sea-level change 3 Sea-level change 10
Rhizoliths 6 Rhizoliths 6 Rhizoliths 8
Herschell Limestone 1 Herschell Limestone 4 Herschell Limestone 11
Tamala Limestone 6 Tamala Limestone 16 Tamala Limestone 24
Eolian-morphology 10 Eolian-morphology 16 Eolian-morphology 28
Active Spearwood dune barrier complex
7 Active Spearwood dune barrier complex
9 Active Spearwood dune barrier complex
13 (Gozzard 2011)
Quindalup parabolic dune complex
4 Quindalup parabolic dune complex
6 Quindalup parabolic dune complex
7 (Gozzard 2010)
43
Furthermore, results of the data interrogation regarding hazards found that there were
six unsuitable sites, based on the two-way hazard analysis (Table 9). An additional two
sites were not suitable based on field observations, because they contain no specific
visible geology, due to the vegetation cover.
TABLE 9: COMPARISON OF HAZARD ASSESSMENT AT GEOSITES USING DATA COLLECTED IN THIS STUDY AND
EXISTING SITE HAZARD ASSESSMENTS (SYRINX 2010B).
Hazard Data
* No hazard This study Gordon’s study (Syrinx 2010b)
Total number of site locations 63 140
Hazard Severity
Low 37 * 12
Moderate 20 15
High 6 18
Subtotal: number of sites with hazards 26 45
Subtotal: number of hazard sites that consistently flagged as moderate or high
26 10
Total: number of sites that are consistently flagged as high in both hazard data layers
6 6
UTILITY OF GIS FOR IDENTIFYING POTENTIAL AREAS OF GEOLOGICAL INTEREST
The GIS software as well as specific MCE processing tools, generated a range of
potential geosites either through simple logic of presence/absence or a sophisticated
approach of weighted analysis in MCE (Johnston 1998; Bolstad 2005; Eastman 2012).
Specifically MCE produced locations indicating potential sites that could be further
surveyed and explored in the field for geological features. The results of the MCE
analysis (Figure 11), demonstrate the creation of the potential locations image with the
geology, access and hazard layers.
44
Quick Bird 4 band satellite image of
Rottnest Island, 2.4m pixel resolution
Water-mask and Land-cover Image
Step 1: Remove water
bodies & create water -mask
Bare Areas indicated in black
(potential geosite locations)
Step 2: Remove vegetation type pixels (via CLUSTER) create
Boolean image of bare areas
Surface geology in Bare Areas
Access Layers: Distance from Bus Stops & Roads to Bare Areas
Management considerations:
Hazards in Bare Areas
Step 3: OVERLAY Geology, Access and Management
criteria to Bare Areas Image
FIGURE 11: VISUAL REPRESENTATION OF DELINEATING BARE AREAS (POTENTIAL LOCATIONS FOR GEOSITES) AND OVERLAYING SPECIFIC CRITERIA PERTAINING TO GEOLOGY, ACCESS
INFRASTRUCTURE AND MANAGEMENT CONSTRAINTS (E.G. HAZARDS).
45
In addition MCE revealed that various combinations of constraints and factors, with
equal weighting, roughly generated the same potential locations within the bare areas,
and appear to cover most of the bare areas (Lillesand et al. 2004). However, when the
hazard images are specified as a constraint in the MCE module, specific locations are
delineated within the bare areas and appear as distinct locations (Figure 12). Removing
the hazard layer or specifying the hazard layer as a factor shows a greater range of
potential areas, yet does not pin point a specific location within the bare areas, as seen
in the comparison between the two images shown in Figure 12. Furthermore, the bare
area images containing potential sites, overlaid with the field geosite layer, revealed
that potential locations were within the bare areas and in proximity of the surveyed
field sites identified in the field investigation (Figure 13). This suggests that using MCE
for suitability is useful in determining a potential location to verify in the field.
46
FIGURE 12: MCE ANALYSIS RESULTS SHOWING THE COMPARISON OF DESIGNATING A HAZARD RASTER IMAGE AS A CONSTRAINT (TOP IMAGE) AND REMOVING HAZARDS FROM
CONSTRAINTS (BOTTOM IMAGE). MCE WITH HAZARDS LAYER PRODUCES SPECIFIC LOCATIONS WITHIN BARE AREAS AND MCE WITHOUT HAZARDS LAYER DELINEATES LARGE ZONES FOR
POTENTIAL SITES.
No Hazard as Constraint (MCE Trial) Potential locations Bare areas
No Hazard as Constraint: Equal Weighted MCE Analysis, Potential Locations in Bare Areas
Hazard as Constraint (MCE Trial) Potential locations Bare areas
Hazard as Constraint: Equal Weighted MCE Analysis, Potential Sites in Bare
47
bare areas potential locations field geosites
bare areas potential locations
Potential Sites in Bare Areas
Field Geosites & Potential Sites in Bare Areas
FIGURE 13: POTENTIAL LOCATIONS IN BARE AREAS (TOP IMAGE) AND FIELD GEOSITES OVERLAYED WITH POTENTIAL SITES, SHOWING THE RESULTS OF MCE
FOR IDENTIFYING POTENTIAL SITES OF GEOLOGICAL INTEREST.
48
The results of this project generated a complete geology database to promote geosites
on Rottnest Island. Additionally this research revealed that by incorporating a desktop
review of literature and existing environmental GIS data sets, coupled with field
investigations and GIS data analysis, it was possible to identify suitable sites of
geological interest for the development of geo-interpretative content for the
educational dimension of geotourism.
49
CHAPTER 4: DISCUSSION
Balancing the economic and environmental needs of natural area tourism destination
creates demand for sustainable systematic planning and management (Newsome and
Dowling 2010). Those responsible for natural area tourism destinations are looking
towards the development of geotourism as a means of providing nature based tourism
product delivery of underutilized natural resources (e.g. RIA 2009; Paik et al. 2010;
Schutte and Booysen 2010; Henriques et al. 2011; Hose 2012b; RIA 2012b). In the
context of geotourism planning and management, this research generated four main
topics of discussion. They include criteria for selection of geosites, the importance of
access in geological tourism, the utility of GIS in geotourism planning and the need for
geo-interpretative themes for the development of geotourism on Rottnest Island. In
addition, the limitations and opportunities of this research approach, discussed in this
section, are recognized as avenues and considerations for further research.
PRIMARY CRITERIA IN THE SELECTION OF SITES FOR GEOTOURISM
Geotourism, a niche form of ecotourism embedded in nature based tourism is founded
on providing safe access to sites of geological interest and interpretation of geological
features and processes (Newsome and Dowling 2010; Hose 2012a). Like any form of
tourism, geotourism has the potential to generate beneficial and adverse impacts that
require careful planning and management (Reynard and Panizza 2005; Newsome and
Dowling 2006). Mitigating adverse impacts and determining suitable sites that will have
maximum benefits and minimal impact can be achieved by identifying the primary
50
criteria for field site selection. Focusing on the foundations of geotourism recognized
by previous research (Pralong 2005; Hose 2006; Reynard 2008; Newsome and Dowling
2010; Pereira and Pereira 2010; Hose 2012a), this research identified that criteria for
the selection of sites for geotourism can be summarized into three main categories,
geology representation, tourism access and safety (management).
Geology and geomorphological processes can be difficult to view and complex to
interpret for the geo-tourist. Hence, geotourism demands visible and interpretable
features or processes, while identifying specific access factors has proven to be critical,
as safety and accessibility for the tourist is imperative (Hose 2006; King 2010).
However, as revealed in this study, sites with extraordinary geology and sites that are
easily accessible may not be the most suitable site for geotourism development. Access
and management criteria may be suitable, but the value of a geological feature due to
site sensitivity, perhaps due to high geoheritage values or high cultural significance
may mean that management may not deem the site suitable for promotion as a tourist
attraction (Brocx and Semeniuk 2007; Brocx 2008). For example, two sites (SZ_S24, and
SZ_S25) located at the west end of Rottnest Island provide an excellent display of
fossilized roots structures and collapsed sea caves, while another site contains 140,000
year old fossil coral. However, at present, these sites are not promoted or made
accessible to the general public because they contain significant environmental
management considerations (e.g. high hazard area and bird nesting grounds) and have
the potential for adverse impact (e.g. removing of fossilized coral).
51
ACCESS IN CONTEXT OF GEOTOURISM
Access is a vital component of any functioning tourism system (Gunn 1988; Newsome
et al. 2013). Central to geotourism planning and management is identifying the balance
between visitor access and visitor safety (King 2010; Paik et al. 2010). Understanding
the various components of access can facilitate the development of protocols to
mitigate adverse effects on the geosite. Therefore, determining access for various
types of tourist requires understanding and identifying fundamental components, such
as available transport, tourist profile, safety issues and potential impacts on field sites
(Gunn 1988; Newsome and Dowling 2010).
In the case of Rottnest Island, access to the island is via the public ferry, private marine
vessels or air transport. Once on the island, specific access to tourist sites is by public
bus, bike or foot. Therefore, recognition of the specific limitations to tourism access is
required to identify accessible field locations for the tourism demographic on Rottnest
Island. In this research, the three tourism categories (as described in Table 6), provided
the basis for understanding access to the geosites identified in this study.
Fundamental to the approach taken was the ability to link human and natural
geospatial data (e.g. hazard issues, bus stop, roads, settlements and geomorphological
processes) to field sites through the component of GIS. Results show (refer to figures
and tables in result section) the approach taken was successful in determining several
field geosites in providing safe access for the Rottnest Island tourist. Geosites were
assessed according to their accessibility in relation to the three tourism categories
52
(Table 6). In addition, sites that had the highest category of hazard, based on a two way
comparison between existing hazard data (Syrinx 2010b) and hazard information
specific to field sites were deemed unsuitable to be proposed as geosites.
The tourism access categories created in this research limit the range of accessible
geological features for some categories because the distance specified is only based on
walking a distance from a focal point. Increasing the number of focal points (e.g. a bus
stop) extends the range of available geology for all categories. Further research is
required in order to refine the tourism access categories and to establish a systematic
approach to determining access criteria.
APPLICATIONS AND LIMITATIONS OF GIS IN GEOSITES IDENTIFICATION
Incorporating Global Positioning Systems (GPS) in conjunction with GIS in geotourism
planning is underutilized. GIS is frequently used in various forms of management
planning from residential development, habitat assessment and geological resource
extraction (Bolstad 2005; Radiarta et al. 2008; Eastman 2012), yet GIS is not fully
embraced as a critical tool for geotourism planning. Some studies have incorporated
elements of GIS through spatially linking sites via GPS points (Gavrila et al. 2011; Vujicic
et al. 2011). For example Schutte and Booysen (2010) identified specific sites of
geological interest in the Kruger National Park by plotting GPS recorded geosites into a
1:500 000 geological map. In this thesis the applications of GIS in assessing the
geotourism potential, demonstrates the value of GIS in depicting areas of geological
interest. Utilizing GIS in geotourism planning can form part of an integrated approach
53
to balancing environmental management and the economic needs of a tourism
destination.
GIS can also provide the spatio-thematic characteristics for geotourism, especially
when combining the human and natural geospatial factors associated with geological
representation, tourism access and information to support management
(requirements) (Bolstad 2005; Schutte and Booysen 2010). Depending on the type of
existing data layers available, geotourism planners can identify specific access and
management factors associated with a natural area allowing planners to avoid areas
that are inaccessible and of high management concern (e.g. high risk or hazard areas)
(Johnston 1998; Nageswara et al. 2008; Musungu and Motala 2012). Using GIS data for
identifying suitable sites of geological interest has proved to be valuable in this
research and demonstrates that the approach is applicable for other natural areas.
GPS linked field data provided the necessary information for the creation of a geosite
database. Having spatial data on access (e.g. bus stops, roads) and management issues
(e.g. hazardous areas, sensitive habitat) allows the planner to determine what areas
can be surveyed in the field. For example, the hazards data layer used in this study
helped to delineate potential locations and unsuitable field geosites. Furthermore,
linking existing data with specific information pertaining to field geosites allowed for
further analysis of the suitability of the geosite for the three tourism access categories.
There are, however, shortcomings in using GIS for identifying specific geological
features. Even with data layers of surface geology and geomorphological processes,
54
determining specific locations of geological features was unattainable. Nevertheless,
having a geology layer in GIS allows the geotourism planner to make inference to
where geological features may be located making these areas potential sites for
survey.
Although this project had a comprehensive data set to work with it was also recognized
in this research that there are potential limitations associated with available existing
GIS data sets. For example, in less geospatially documented areas identifying locations
to survey in the field and combining field data with existing layers could prove
challenging and require further analysis of available topographical geospatial data (e.g.
digital elevation models (DEM) and aerial photographic imagery). Topographic analysis
can aid in a better understanding of various landscape cover (e.g. flood zones, hazard
assessment type data) (Johnston 1998; Bolstad 2005). Comprehensive analysis of DEM
can determine steep surfaces including cliffs and areas facing a specific direction
(facing a prevailing wind) that are subject to erosion. In addition, using DEM and aerial
photography can determine access routes to potential sites. Furthermore, where there
is limited geospatial data available, further research is required to incorporate GIS
analysis into geotourism planning, especially in preliminary field investigations. Where
there is limited geospatial data, sourcing publically available data sets (e.g. world
digital elevation model at 90 m pixel resolution, Google earth imagery) could be used
as surrogates, for obtaining access and land cover information for field investigations.
55
GEOTOURISM OPPORTUNITIES FOR ROTTNEST ISLAND ACCORDING TO GEOLOGICAL
THEMES
In the context of geotourism, geological features provide the educative platform to
generate awareness and understanding of the importance of geology and geological
processes, through modes of interpretation that demonstrate and explain the
significance of earth’s fluctuating climates (Hose 2006; Sharples 2012). Results of this
research identified that Rottnest has extraordinary local, regional and globally
significant geological features, including fossilized coral, stromatolites, rhizoliths and
evidence of major Quaternary sea-level change events (Brocx 2008). The globally
significant geological evidence of high and low sea-levels is useful information for
determining the focus of a number of interpretative themes (pg. 36 Table 7) where the
intention is to provide educational content on the geology of Rottnest Island. This
material can then be used to match the visible geological and geomorphological
evidence of the island to information provided in the interpretative products (e.g.
interpretative panels, maps, guidebooks, visual displays and phone applications).
In addition, the results revealed that the inland lakes system offers Rottnest Island
Authority the platform to launch geotourism on the island. The lake area contains an
abundance of geological features, has the potential for suitable tourism access and has
minimal environmental management considerations, making this area an excellent
focus area for the development of geo-educational content. Furthermore, a
combination of the RIA Coastal Walk Trail spatial data with the geosite database
produced in this research can be used for the creation of a geo-interpretative trail
56
around the lakes, with the major educational focus on environmental change,
specifically in relation to Quaternary sea-level changes and the connection of Rottnest
Island to the mainland.
This study found that Rottnest Island has suitable sites of geological interest for the
delivery of interpretative education content, and this research provides an systematic
approach which incorporated field studies and GIS analysis tools for exploring the
geotourism value of any natural area based on its geological representativeness,
tourism access and environmental management considerations. However, more
specific information (e.g. surface geology, geomorphology, hazard considerations) and
further research through field verification, geared towards collecting geospatial data
(specific for) geotourism planning is required and offers an area of future research.
57
CHAPTER 5 CONCLUSION
The aim of this research was to investigate the geotourism potential of a natural area
by utilizing an approach that combined desktop reviews, field investigation and GIS
analysis. In particular, this research investigated the geotourism opportunities available
on Rottnest Island by assessing potential sites of geological interest based on
geological representativeness, tourism access and management constraints. This study
has confirmed that Rottnest Island has sites with geotourism potential and that GIS,
combined with field studies, has been instrumental in helping to identify potential sites
for geotourism.
Assessing the geotourism potential of Rottnest Island provided the context and
information for evaluating how to develop geotourism as a means to expand the
tourism profile of the area. In addition, this research provides a guide to the geo-
interpretative content and valuable data that can support geotourism product planning
and site specific information regarding environmental management considerations.
Although this research provides a valuable information for geotourism product
planning, it is recognised that further research is required in order to refine the primary
criteria for field site selection. This will help mitigate adverse impacts by determining
suitable sites that will have maximum benefits and minimal environmental impact.
The research has created a GIS geosite database that contains information for a
number of suitable sites of geological interest that can be used for the development of
geotourism on Rottnest Island. The main findings from this project will contribute to
58
existing tourism access and environmental management strategies (e.g. coastal walk
trail) on Rottnest Island. In particular, the information gathered in this research can
assist in the creation of geo-interpretation products (e.g. geo-tour guide books, oral
content for educative geo-tours, interactive mobile phone applications, interpretative
panels) and specifically the creation of a geo-interpretative trail on Rottnest Island.
Having the geosites and specific geological data attached to a GPS location not only
provides the tools for implementing interpretative geosites in the field, but also
provides bilateral interest for the visitors. The data can be linked to interactive geo-
interpretation technology, such as hand held devises (e.g. mobile phones or interactive
touch screens) and interactive maps. There are additional opportunities for further
research in developing geotourism products for RIA, which will provide scientific
educative content, with the aim of generating an understanding, appreciation and
awareness of the geological environment of Rottnest Island.
59
REFERENCES
ArcGIS (2012a). Desktop 10 Tutorials, Spatial Analysis Tutorial Pdf. ArcGIS Resourse Centre, . California, USA, 1995-2012 Environmental Systems Research Institute, Inc. (ESRI) Online tutorials.
ArcGIS. (2012b). Desktop 10 Tutorials,Overlay Toolset ArcGIS Resourse Centre, Retrieved October 15, 2012, from http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#/Overlay_analysis_approaches/009z000000rt000000/.
Arias, A., Bent, R. and Wadsworth, R. (2007). Overview of Exisiting Walking Trail Classification Systems: Walking Trails Classification and Improvement Project. Department of Sustainability and Environment. Melbourne, Victoria, Australia: 1-46.
Backhouse (1993). Holocene Vegetation and Climate Record from Barker Swamp, Rottnest Island, Western Australia. Journal of the Royal Society of Western Australia. 76: 53-61.
Bailey, G.N. (1977). Shell Mounds, Shell Middens, and Raised Beaches in the Cape York Peninsula. Mankind 11(2): 132-143.
Bindon, P., Dortch, C. and Kendrick, G. (1978). A 2500 Year Old Pseudo Shell Midden on Longreach Bay, Rottnest Island, Western Australia. Australian Archaeology 8: 162-171.
Bolstad, P. (2005). GIS Fundamentals, a First Text on Geographic Information Systems. White Bear Lake, Minnesota, USA, Eider Press.
Bowdler, S. (1990). Before Dirk Hartog: Prehistoic Archeaological Research in Shark Bay, Western Australia. Australian Archaeology 30: 46-57.
Brocx, M. (2008). Geoheritage: From Global Perspectives to Local Principles for Conservation and Planning. Perth, Western Australia, Western Australian Museum. 1-175.
Brocx, M. and Semeniuk, V. (2007). Geoheritage and Geoconservation -History, Definition, Scope and Scale. Journal of the Royal Society of Western Australia 90: 53-87.
Brooke, B. (2001). The Distribution of Carbonate Eolianite. Earth-Science Reviews 55(1–2): 135-164.
Brooke, B., Creasey, J. and Sexton, M. (2010). Broad-Scale Geomorphology and Benthic Habitats of the Perth Coastal Plain and Rottnest Shelf, Western Australia, Identified in a Merged Topographic and Bathymetric Digital Relief Model. Journal of Remote Sensing 31(23): 6223-6237.
Carew, J.L. and Mylroie, J.E. (1997). Chapter 3A. Geology of the Bahamas. Geology and Hydrogeology of Carbonate Islands. Developments in Sedimentology. L.H. Vacher and T.M. Quinn. Florida, USA, Elsevier: 91-139.
Church, J.A. and White, N.J. (2006). A 20th Century Acceleration in Global Sea-Level Rise. Geophysical Research Letters 33(L01602): 1-4.
60
Clark Labs (2012). Using Multi-Criteria Evaluation Tools for Sustainable Forest Management. CS_LP_SustainForest1-6.doc. C.U. Clark Labs. Worcester,Massachusetts, USA: 2.
Congalton, R.G. and Green, K. (2009). Assessing the Accuracy of Remotely Sensed Data, Principles and Practices. Boca Raton, Florida, USA, Taylor and Francis Group, CRC Press.
Copp, L., Ed. (2001). Geology & Landforms of the South-West. Bush Book. Kensington, WA, Australia, Department of Conservation and Land Management. 72.
Dowling, R. and Newsome, D. (2010). Chapter 1. Geotourism: A Global Activity. Global Geotourism Perspectives. R. Dowling and D. Newsome. London, United Kingdom, Goodfellow Publishers: 1-17.
Drew, G., Grocke, C. and Cahalan, P. (2003). Guidelines for Producing Trail Signage: Direction, Interpretation and Management. Prepared for: SA Tourism Commission and Recreation Trails Signage and Interpretation Working Group 2002/03. Adeliade, South Australia, Australia: 1-43.
Eastman, J.R. (2012). Idrisi Selva Manual: Version 17, IDRISI Production source code 1987-2012, Clark University: 322.
Fairbridge, R.W. (1961). Eustatic Changes Is Sea Level. Physics And Chemistry Of The Earth. Pergamon, London. (4): 99-185.
Fung, L.W. and Newsome, D. (2010). Geoheritage of Hong Kong: Interpretation for Geotoursim. School of Environmental Science. Perth, Murdoch University. Ecotoursim Honours: 140.
Gavrila, I.G., Man, T. and Surdeanu, V. (2011). Geomorphological Heritage Assessment Using GIS Analysis for Geotourism Development in Macin Mountains, Dobrogea, Romania. GeoJournal of Tourism and Geosites 8(2): 198-205.
Geological Survey of Canada. (2008). Past Lives: Chronicles of Canadian Paleontology, Pethei Stromatolites. Retrieved Oct 20, 2011, from http://gsc.nrcan.gc.ca/paleochron/03_e.php
Gozzard, J.R. (2011). Wa Coast -Rottnest Island Digital Datasets. Geological Survey of Western Australia. Perth, WA, Australia.
Greenstein, B.J. and Pandolfi, J.M. (2008). Escaping the Heat: Range Shifts of Reef Coral Taxa in Coastal Western Australia. Global Change Biology 14(3): 513-528.
Grey, K., Moore, L.S., Burne, R.V., Pierson, B.K. and Bauld, J. (1990). Lake Thetis Western Australia: And Examaple of Saline Lake Sedimentation Dominated by Benthis Microbial Processess. Australian Journal of Freshwater Research 41: 275-300.
Gunn, E. (1988). Tourism Planning: Basics, Concepts, Cases (2nd Edition). New York, United States of America, Taylor and Francis.
Hearty, P.J. (2003). Stratigraphy and Timing of Eolianite Deposition on Rottnest Island, Western Australia. Quaternary Research 60: 211-222.
Hearty, P.J., Hollin, J.T., Neummann, C.A., O'Leary, M.J. and McCulloche, M. (2007). Global Sea-Level Fluctuations During the Last Interglaciation (Mis 5e). Quaternary Science Reviews, Elsevier 26: 2090-2112.
61
Hearty, P.J. and O'Leary, M.J. (2008). Carbonate Eolianites, Quartz Sands, and Quaternary Sea-Level Cycles, Western Australia: A Chronostratigraphic Approach. Quaternary Geochronology 3: 26-55.
Henriques, M., dos Reis, R., Brilha, J. and Mota, T. (2011). Geoconservation as an Emerging Geoscience. Geoheritage 3(2): 117-128.
Heywood, I., Cornelius, S. and Carver, S. (2002). Chapter 6. Data Analysis. An Introduction to Geographical Information Systems. United Kingdom, Prentice Hall. 2nd: 295.
Hose, T. (2012a). 3g’s for Modern Geotourism. Geoheritage 4(7): 1-18. Hose, T. (2012b). Editorial: Geotourism and Geoconservation. Geoheritage 4(1): 1-5. Hose, T.A. (2005). Geo-Tourism: Appreciating the Deep Time of Landscapes. . Niche
Tourism: Contemporary Issues, Trends and Cases. Novelli. London, Elsevier: 27-37.
Hose, T.A. (2006). Geotourism and Interpretation. Geotourism. R.K. Dowling and R. Newsome. London, Elsevier Ltd,: 221-241.
Hovland, M., Ruestlatten, H. and Pederson, R.B. (2010). Seepage-Related Stromatolites? Retrieved April 7, 2012, from http://www.geolsoc.org.uk/page7328.html.
IPCC (2007). Climate Change 2007: Synthesis Report, Summary for Policymakers. Key findings and uncertainties contained in the working group contributions of the Fourth Assessment Report. Intergovernmental Panel on Climate Change. Geneva: 22.
Jacobs, K., Nannup, N. and Revell, G. (2008). Rottnest Island (Wadjemup) Coastal Walk Trail: Concept Plan. G. Macgill. North Fremantle, Western Australia, Prepared by Ecoscaped Australia for, The Government of Western Australia, Rottnest Island Authority.
Johnston, C.A. (1998). Geographic Information Systems in Ecology. Oxford, United Kingdom., Blackwell Science Publications. 239.
Joyce, E. (2010). Australia’s Geoheritage: History of Study, a New Inventory of Geosites and Applications to Geotourism and Geoparks. Geoheritage 2(1): 39-56.
Kendrick, G.W., Wyrwoll, K.-H. and Szabo, B.J. (1991). Pliocene-Pleistocene Coastal Events and History Along the Western Margin of Australia. Quaternary Science Reviews 10(5): 419-439.
King, L.M. (2010). Geotourism in the Hawaiian Islands. Chapter 9 in Geotourism: The tourism of geology and landscape. D. Newsome and R. Dowling. Oxford, United Kingdom, Goodfellow Publishing Limited: 115-125.
Lewis, I.D. (2010). Chapter 14. Kanawinka, Australia: Setting up, Marketing and Ensuring the Future of a Large Geopark. Global Geotourism Perspectives. R. Dowling and D. Newsome. London, United Kingdom, Goodfellow Publishers: 192-214.
Lillesand, T.M., Kiefer, R.W. and Chipman, J.W. (2004). Remote Sensing and Image Interpretation. New Jersey, USA, John Wiley and Sons. 753.
McNamara, K. (2009). Stromatolites. Whelshpool, WA, Western Australia Museum.
62
Murray-Wallace, C.V. and Kimber, R.W.L. (1989). Quaternary Marine Aminostratigraphy: Perth Basin, Western Australia. Australian Journal of Earth Sciences 36(4): 553-568.
Musungu, K. and Motala, S. (2012). Participatory Multi-Criteria Evaluation and GIS: An Application in Flood Risk Analysis. FIG Young Surveyors Conference: Knowing to Create the Future. Rome, Italy, Europe. Workshop 1.2, 6204: 1-14.
Nageswara Rao, K., Subraelu, P., Venkateswara Rao, T., Hema Malini, B., Ratheesh, R., Bhattacharya, S., Rajawat, A. and Ajai, A. (2008). Sea-Level Rise and Coastal Vulnerability: An Assessment of Andhra Pradesh Coast, India through Remote Sensing and GIS. Journal of Coastal Conservation 12(4): 195-207.
Newsome, D. and Dowling, R. (2006). Chapter 1: The Scope and Nature of Geotourism. Burlington, Elsevier Ltd.,. 3-25.
Newsome, D. and Dowling, R. (2010). Geotourism: The Tourism of Geology and Landscape Oxford, Goodfellow.
Newsome, D., Dowling, R. and Leung, Y. (2012). The Nature and Management of Geotourism: A Case Study of Two Established Iconic Geotourism Destinations. Tourism Management Perspectives 2-3: 19-27.
Newsome, D., Moore, S.A. and Dowling, R.K. (2013). Natural Area Tourism: Ecology, Impacts, and Management Clevedon ; Buffalo, In print at Channel View Publications.
Newsome, D., Moore, S.A., Dowling, R.K. and NetLibrary, I. (2002). Natural Area Tourism: Ecology, Impacts, and Management. Clevedon ; Buffalo, Channel View Publications. 340.
Paik, I.S., Huh, M., Kim, H., Kim, S.J. and Newsome, D. (2010). 10. The Cretaceous Fossil Sites of South Korea: Identifying Geosites, Science and Geotourism. Chapter 10 in Geotourism: The Tourism of Geology and Landscape. D. Newsome and R. Dowling. Oxford, United Kingdom, Goodfellow Publishing Limited: 126-141.
Palmer, S. and Newsome, D. (2010). Ecotourism on Rottnest Island: A Review of the Current Status and Opportunities Perth, Western Australia, Murdoch University: 22.
Pereira, P. and Pereira, D. (2010). Methodological Guidelines for Geomorphosite Assessment. Geomorphologie: relief, processus, environnement, 2: 215-222.
Pereira, P., Pereira, D. and Caetano Alves, M.I. (2007). Geomorphosite Assessment in Montesinho National Park, Portugal. Geographica Helvetica 62.
Playford, P.E. (1983). Geological Research on Rottnest Island. , Western Australia Geological Survey Research Report. 66. 10-15. 66: 10-15.
Playford, P.E. (1988). Guidebook to the Geology of Rottnest Island, Geological Society of Australia (WA division).Geological Survey of Western Australia. 1-67. 1-67.
Playford, P.E. (1997). 27. Chapter 27 Geology and Hydrogeology of Rottnest Island, Western Australia. . Geology and Hydrogeology of Carbonate Islands. L.H. Vacher and T.M. Quinn, 2004, Elsevier. 54 783-810.
Playford, P.E. and Leech, R.E.J. (1977). Geology and Hydrogeology of Rottnest Island. Perth, Australia, Geological Survey of Western Australia. 1-98.
63
Pralong, J.P. (2005). A Method for Assessing Tourist Potential and Use of Geomorphological Sites. Geomorphologie: relief, process, environment 3: 189-196.
Radiarta, N., Saitoh, S.I. and Miyazono, A. (2008). GIS-Based Multi-Criteria Evaluation Models for Identifying Suitable Sites for Japanese Scallop (Mizuhopecten Yessoensis) Aquaculture in Funka Bay, Southwestern Hokkaido, Japan. Aquaculture 284: 127-135.
Reynard, E. (2008). Scientific Research and Tourist Promotion of Geomorphologica Heritage. Geogr. Fis. Dinam. Quat 31: 225-230.
Reynard, E. and Panizza, M. (2005). Geomorphosites: Definition, Assessment and Mapping. Geomorphologie: relief, processes, environment 3: 177-180.
RIA (2009). Rottnest Island Management Plan 2009-2014: Revitalised and Moving Forward. Tourism Department of Western Australia. Perth, Government of Western Australia, Rottnest Island Authority,: 1-128.
RIA (2010). Rottnest Island GIS Digital Database. Fremantle, WA, Australia, Distributor, Murdoch University.
RIA (2011). Rottnest Island Authority, Annual Report 2010-2011. Rottnest Island celebrating 100 years of tourism 1911-2011. Fremantle, Rottnest Island Authority: 1-88.
RIA. (2012a). Rottnest Island Authority Home Page. Retrieved August 5, 2012, from http://www.rottnestisland.com/rottnest-island-authority.
RIA. (2012b). Rottnest Island Authority: Coastal Walk Trail. Retrieved August 4, 2012, from http://www.rottnestisland.com/industries/environmental-initiatives/coastal-walk-trail.
Richardson, L., Mathews, E. and Heap, A. (2005). Geomorphology and Sedimentology of the South Western Planning Area of Australia: Review and Synthesis of Relevant Literature in Support of Regional Marine Planning. A.G. Geoscience Australia, Geoscience Australia, Records 2005/17,: 1-124.
Schutte, I.C. and Booysen, I. (2010). 9. Geosite Identification as Elements of Promoting Geotourism in a Wildlife Hotspot: The Kruger National Park, South Africa. Chapter 9 in Global Geotourism Prespectives. R. Dowling and D. Newsome. Oxford, United Kingdom, Goodfellow Publishers Limited: 124-136.
Sharples, C. (2012). Geodiversity & Climate Change. Earth Heritage magazine:The geological and landscape conservation magazine(37): 26-29.
Short, A.D. (2005). Beaches of the Western Australian Coast: Eucla to Roebuck Bay. Sydney, Australia, Sydney University Press.
Smallwood, C., Beckley, L.E. and Sumner, N.R. (2006). Shore Based Recreational Angling in the Rottnest Island Reserve, Western Australia. Tourism in Marine Environments 5: 238-251.
Spooner, M.I., Deckker, P.D., Barrows, T.T. and Fitfield, L.K. (2011). The Behaviour of the Leeuwin Current Offshore Nw Australia During the Last Five Glacial–Interglacial Cycles. Global and Planetary Change 75: 119-132.
Storr, G.M. (1963). Some Factors Inducing Change in the Vegetation of Rottnest Island. Western Australia Naturalist 9: 19-22.
64
Syrinx (2010a). Coastal Walk Trail: Stage 2 Site Development Plan for Rottnest Island Authority. RPT-1002-001. Syrinx Environmental Pl. Perth, Western Australia.
Syrinx (2010b). Coastal Walk Trial GIS Digital Database Created for Rottnest Island Authority. RIACWT Stage 2 Development Plan. Syrinx Environmental Pl. Perth
Syrinx (2012). Coastal Walk Trial GIS Digital Database Created for Rottnest Island Authority. Updated Database from the 2010 Rottnest Island Authority Coastal Walk Trail Stage 2 Development Plan, Syrinx Environmental Pl., Perth, WA, Australia.
Szabo, B.J. (1978). Uranium-Series Age of Coral Reef Growth on Rottnest Island, Western Australia Marine Geology. Elsevier Scientific 29: M11-M15.
Tapsell, P., Newsome, D. and Bastian, L. (2003). Origins of Yellow Sand from Tamala Limestone on the Swan Coastal Plain, Western Australia. Australian Journal of Earth Sciences 50: 331-342.
Thomas, M.F. (2012). A Geomorphological Approach to Geodiversity: Its Applications to Geoconservation and Geotourism. Questions Geographicae 31(1): 81-89.
Vacher, L.H. and Quinn, T.M. (2004). Geology and Hydrogeology of Carbonate Islands. Develoment in Sedimentology, Elsevier. 54: 948.
Vujicic, M.D., Vasiljevic, D.A., Markovic, S.B., Hose, T.A., Lukic, T., Hadzic, O. and Janicevic, S. (2011). Preliminary Geosite Assessment Model (Gam) and Its Application on Fruska Gora Mountain, Potential Geotourism Destination of Serbia. Acto geographica Slovenica 51(2): 361-377.
Wyrwoll, K.-H., Zhu, Z., Kendrick, G., Collins, L. and Eisenhauer, A. (1995). Holocene Sea-Level Events in Western Australia: Revisiting Old Questions. Journal of Coastal Research 17: 321-326.
65
APPENDICES
Appendix 1: Literature review of geology of Rottnest Island……………………………………66
Appendix 2: Sample of the data collection table used for field investigation…………..93
Appendix 3: Criteria evaluation sheet used for field investigation…………………………. 94
Appendix 4: Summary table of field site and their specific geological features……… 96
Appendix 5: Additional images plates of geological features on Rottnest Island……. 98
Appendix 1
Geology of Rottnest Island and the Development of Major Interpretative Themes for Geotourism:
A Literature Review
April, 2012
1
Literature Review: Table of Contents
Table of Contents ............................................................................................................... 1
Introduction ....................................................................................................................... 2
Geological Research on Rottnest Island –A historical perspective ..................................... 4
Geology and Geomorphology of Rottnest Island ............................................................... 5
Geographical setting ........................................................................................................... 5
Shoreline Features (Geomorphology) ................................................................................. 9
Weathering and Erosion .............................................................................................. 9
Modern Reefs ............................................................................................................. 10
Sand Dunes ................................................................................................................ 10
Salt Lakes & Swamps ................................................................................................. 11
Stromatolites.............................................................................................................. 12
Geology: Sedimentation Stratigraphy ............................................................................... 15
Tamala Limestone ...................................................................................................... 15
Rottnest Limestone .................................................................................................... 15
Herschell Limestone ................................................................................................... 16
Late Pleistocene and Quaternary sea-level change history .............................................. 17
Elevated Fossil Coral Reefs ......................................................................................... 19
Elevated Platforms & Notches (evidence of sea-level change) .................................. 19
Shell Deposits ............................................................................................................. 20
Themes for Geo-interpretation ......................................................................................... 21
Conclusion ..................................................................................................................... 24
References ..................................................................................................................... 25
2
INTRODUCTION
Rottnest Island (Figure 1) is an A-class nature reserve which is located approximately
18 km west off the coast of Perth, Western Australia, and which contains important
geological, biophysical, cultural and wildlife resources (Palmer & Newsome, 2010). It
attracts approximately 560,000 visitors annually (RIA 2011) and holds an iconic local,
national and international tourism status for Australia. Rottnest Island’s unique
carbonate geologic features (stromatolites, evidence of sea level change, exposures of
Late Pleistocene aeolionite and Holocene dunes) (Playford, 1988), present (examples
of) geophysical illustrations particularly relating to global climate change, and offer
opportunities for the development of geotourism where the focus of tourism is on
geology and landforms. In particular, geotourism is founded on providing access to the
interpretation of the geologic features and processes (e.g. mechanisms of weathering,
erosion and tectonics) of a natural area. Newsome and Dowling (2010) describe it as
the context and means to incorporate geological scientific data into accessible and
engaging information, in order to generate public awareness and additional nature-
based tourism products in suitable locations. The main elements of their work
emphasise the recognition and identification of geo-sites and the importance of
interpretation via pamphlets, information panels, self-guided trails and guided tours
(Dowling and Newsome 2010).
The literature review presented here forms part of a wider study (involving the
evaluation of available literature, accessing environmental geological GIS datasets and
conducting field studies) centred on developing a strategic approach to assessing the
geotourism potential of natural areas and in this case Rottnest Island. The objectives of
this review therefore are to:
1. Document what is known about the geology of Rottnest Island.
2. Focus attention on Rottnest Island geology that can be interpreted in the
global context; and
3. Identify geological features on Rottnest Island that can be used as
interpretative themes and can subsequently be used in the development of
geo-educational materials on Rottnest Island.
3
FIGURE 1: MAP OF ROTTNEST ISLAND, WESTERN AUSTRALIA, WITH INSERT SHOWING LOCALITY OF THE ISLAND IN RELATION TO THE PERTH COASTLINE. SOURCE (RIA 2012)
4
GEOLOGICAL RESEARCH ON ROTTNEST ISLAND –A HISTORICAL PERSPECTIVE
The literature on the geology of Rottnest Island is limited to the work of a few key
researchers ( e.g. Teichert, 1950; Fairbridge, 1953, 1961; Playford, 1976, 1983, 1988).
Most of the geological research took place from the mid-1950’s to the late 1980’s. The
first substantial geology research conducted on Rottnest Island, dealt with evidence of
Quaternary sea-level change, and was carried out by Teichert (1950). Additional
research on Quaternary sea-level change was subsequently conducted by Fairbridge
(1953), Glenister, Hassell and Kneebone (1959), Hassell and Kneebone (1960) and
Fairbridge (1961). The most comprehensive and widely cited work is that of Playford
(1977), especially in relation to his work on the groundwater potential on Rottnest
Island in 1976. This and other work has resulted in three major publications (Playford,
1976, 1983; Playford & Leech, 1977), and included a guidebook, accompanied by a
geological map (Playford, 1988), which was produced as a researcher’s guide, and is
still to this day the most comprehensive geological depiction of Rottnest Island.
Table 1 presents an overview of the major published work on Rottnest Island. The
major work on Pleistocene and Holocene sea-level changes on Rottnest Island is
covered by (Teichert, 1950; Hassell & Kneebone, 1960; Fairbridge, 1961; Playford,
1976; Playford & Leech, 1977; Playford 1988, 1997; Kendrick, Wyrwoll & Szabo, 1991;
Brooke, Creasey & Sexton, 2010). Recent work on beach classification (Short, 2005)
and GIS spatial datasets (Gozzard, 1990, 2010; Syrinx Environmental Pl, 2010) has
added to the data provided by Playford (1976, 1988, 2004), and additionally present a
platform from which to investigate geotourism opportunities in the wider global
content, and particularly in the context of climate change.
TABLE 1: A SUMMARY OF THE PRIMARY RESEARCHERS AND GEOLOGIC RESEARCH CONDUCTED ON ROTTNEST
ISLAND FROM 1920 TO 2010.
Date Research area Author(s)
1921 Early research on geology and vegetation (Sommerville 1921); (Aurousseau and Budge 1921)
1950 Quaternary sea-level change evidence (Teichert 1950)
1960-1963
Quaternary vegetation (fossil soils and Tuart fossil woodlands), investigating evidence of sea-level change times and origins
(Hassell and Kneebone 1960), (Churchill 1960) (Fairbridge 1961), (Storr 1963)
1976 Hydrogeology, ground water investigation & (Playford 1976)
5
geological mapping
1977 Geology and geomorphology of Rottnest Island (Playford and Leech 1977)
1989 Geology guidebook for science research (Playford 1988)
1991 Quaternary palynology Barker Swamp & Sea level change. First environmental geographical map series
(Backhouse 1993); (Kendrick et al. 1991); (Gozzard 1990)
1997 Book chapter, Geology of Rottnest Island (Playford 1997)
2005 Coastal zone classification of Rottnest Island (Short 2005)
2010 GIS map series and RIA Coastal Walk Trail Plan and interpretative themes; Bathymetry and sea-level changes
(Jacobs et al. 2008; Gozzard 2011);(Syrinx 2010); (Brooke et al. 2010)
GEOLOGY AND GEOMORPHOLOGY OF ROTTNEST ISLAND
GEOGRAPHICAL SETTING
Rottnest Island (Figure 1) is one of three Cenozoic carbonate islands, including Carnac
and Garden Island, located in a tectonically stable region within latitude 32o S, on the
continental shelf off the coast of Perth (Figure 2) (Szabo 1978; Playford 1997; Vacher
and Quinn 2004; Brooke et al. 2010). Rottnest Island is part of what is recognised as
one of the world’s most extensive Quaternary aeolian limestone dune systems
(Playford 1997; Brooke et al. 2010), and is part of a chain of aeolian dunes known as
the Spearwood Dune System, believed to have formed some 140,000 to 130,000 years
ago during a glacial period (Playford 1988; Hearty 2003; Hearty et al. 2007). This
relatively stable latitudinal region is composed of shoals and a chain of limestone
islands stretching over the Rottnest continental shelf, which extends from Geraldton to
the north to Cape Leeuwin in the south (Richardson et al. 2005; Brooke et al. 2010).
Bathymetry shows a late Quaternary history of dune systems, parallel ridges and reefs
and evidence of previous shorelines (Figures 2 and 3) (Richardson et al. 2005).
6
FIGURE 2: : LIDAR IMAGE SHOWING THE MARINE BATHYMETRY AND DIGITAL TOPOGRAPICAL, ILLUSTRATING
THE PARALLEL RIDGES, PREVIOUS SHORELINES OF THE ROTTNEST SHELF AND SWAN COASTAL PLAIN, WESTERN
AUSTRALIA, AND SHOWING LOCALITY OF ROTTNEST ISLAND IN RELATION TO THE PERTH COASTLINE AND CHAIN
OF ISLANDS, OF THE SPEARWOOD DUNE SYSTEM, WITHIN LATITUDE 32O (CARNAC ISLAND & GARDEN
ISLANDS). SOURCE (GOZZARD 2011)
The large aeolian dunes that make up Rottnest Island consists of cemented windblown
(aeolian) limestone, which formed when the island was connected to the mainland,
some 140, 000 years ago, when sea-level was much lower and the coastline was 12km
west of Rottnest Island (Playford 1988; Hearty 2003). The coastline of some 20,000
years ago was also beyond Rottnest Island, when sea-level was ~130m from the
present Perth shoreline (Figure 3).
7
FIGURE 3: FLUCTUATIONS OF THE ROTTNEST ISLAND AND SWAN COASTAL PLAIN SHORELINE OVER THE LAST
18, 000 YEARS. IMAGES DEMONSTRATING THE LOCATION OF THE ANCIENT SWAN RIVER AND THE ANCESTRAL
SHORELINE (IMAGE 1) WHEN SEA-LEVEL WAS LOW AND THE SHORELINE OF ROTTNEST ISLAND WAS ~12KM
WEST OF THE ISLAND. SOURCE (PLAYFORD, 1988).
The sediments comprising the Spearwood Dune System developed from the Tamala
Limestone, which is predominantly cemented quartz sands, but also contains an
extensive coastal assemblage of shells and coral fragments (Playford 1988). The
Tamala Limestone formed as windblown deposits during the Pleistocene age. Large
aeolian dunes reflect the accumulation of sand blown inland and coastal migration of
the dunes is evident in the cross-bedding of Tamala Limestone cliffs (Copp 2001).
Results from current dating techniques show that the Rottnest Islands Tamala
limestone formed during high and intermediate sea-level conditions and can be dated
to ~140, 000 years old (Brooke 2001; Brooke et al. 2010), (Playford 1988). The islands
distinct shoreline of reef platforms, which cut into aeolionite Tamala limestone
ridges/cliffs, demonstrate historical sea-level changes, as evidenced in the notch,
ridges and marine/terrestrial cemented assemblages within limestone cliffs (Playford
1997; Short 2005).
The global context of Rottnest Island in relation to various Carbonate islands, reefs and
atolls around the world, is that aeolionite deposits are generally found in the northern
and southern hemispheres between 20o and 40o latitude (Figure 4) (Brooke 2001). The
8
islands of Bermuda, the Bahamas, Cancun Mexico and Rottnest are part of the “world’s
carbonate belt”(Fairbridge & Johnson, 1968, cited in (Vacher and Rowe 1997), and
they all exhibit classic carbonate island features (Vacher et al. 2004). Their features
comrise fresh water lenses (water located beneath limestone), undulating
topographical dune hills and steeply angled cross-bedding cliffs that often contain
fossilized marine deposits, paleosols (fossilized sediments) and rhitholiths (fossil root
structures) (Playford 1988, 1997; Vacher et al. 2004).
FIGURE 4: GLOBAL DISTRIBUTION OF QUATERNARY CARBONATE AEOLINITE IN THE CARBONATE BELT. SOURCE
(BROOKE 2001).
One major difference between Rottnest Island and other carbonate islands previously
mentioned, is that Rottnest Island is located in a relatively tectonically stable region,
whereas the islands in Bermuda and the Bahamas are located in a region of tectonic
and volcanic activity (Playford 1997; Brooke et al. 2010) (Vacher et al. 2004). Some
debate exists regarding tectonic influences on Rottnest Island during Quaternary
Holocene sea-level change events (Kendrick et al. 1991; Lambeck and Nakada 1992;
Wyrwoll et al. 1995; Playford 1997; Brooke et al. 2010). However, according to Brooke
et al. (2010), the elevated fossil corals (2-3m above present sea-level) found on some
exposed Tamala Limestone cliffs, have been dated to the Last Interglacial (120ka-130ka
years ago).This correlates with sea-levels at this time (Figure 9), and therefore verifies
the stability of the Rottnest Island Shelf during the Quaternary (Brooke et al. 2010).
9
SHORELINE FEATURES (GEOMORPHOLOGY)
Rottnest Island’s 36km coastline is composed of 63 sand beaches (Short 2005), rocky
calcarenite headlands, bays and shallow platforms (extending ~200m from the shore in
some areas). These shoreline platforms cut into the Late Pleistocene and early
Holocene dunes (Tamala Limestone) which occur as shoreline notches, and lie just
below the overhanging visor of the cliffs (Figure 10) (Playford 1997). The bays with less
wave action tend to display horizontal platforms and storm benches close to the
water, where the highest platforms are found at headlands facing the predominant
southwest swells.
WEATHERING AND EROSION
The distinctive erosion features of Rottnest Island are seen at other locations along the
West Australian coast, and there is still some debate over the exact processes
responsible for the specific notches and platform formations of the Rottnest shoreline.
It is thought, however, that erosion of the Tamala Limestone is a result of a
combination of chemical corrosion (saltwater), bioerosion (marine organisms) and
mechanical erosion (wave action) (Playford 1997). These are also main erosional
processes responsible for the shoreline platforms and notches around Rottnest Island.
The various degrees of lithification (cementation) of the limestone, therefore, give rise
to varying degrees of erosion. Limestone cliffs and intertidal shoreline platforms (such
as those seen on Rottnest Island) are subject to wetting and drying according to tidal
fluctuations and wave action, resulting in slow weathering (Masselink and Hughes
2003).
Fragility of the limestone is related to the level of lithification, the amount of rhizoliths
and solution pipes within the limestone and the extent of existing erosion
(weathering). Coastal Tamala Limestone cross-bedded dunes consist of hard calcrete
top layers underlain with softer limestone that contains well cemented calcite root
systems (rhizoliths) (Semeniuk and Searle 1987; Playford 1997). This layering system,
filled with its calcified root structures and solution pipes, forms a brittle and fragile
coastline. Figure 5 shows the crossing bedding and demonstrates bioerosion and
mechanical erosion of the Tamala Limestone.
10
5: STRUCTURAL COMPONENTS WHICH CONTRIBUTE TO THE FRAGILITY OF TAMALA LIMESTONE; CROSS-
BEDDING STRATIFICATION (BLUE ARROW) AND PALEOSOLS (RED ARROW) OF THE TAMALA LIMESTONE CLIFF AT
FISH HOOK BAY, ROTTNEST ISLAND, AND RHIZOLITHES AND SOLUTION PIPE WITH BIVALVES EROSION AT
FAIRBRIDGE BLUFF. SOURCE (RUTHERFORD, 2011)
MODERN REEFS
The geographical location and together with the south flowing warm Leeuwin Current
has allowed Rottnest Island to develop substantial reef systems. The coral assemblages
found on the island today (Pocillopora Reef) are dominated by a Hermatypic coral,
predominantly Pocillopora sp (Szabo 1978), unlike the coral found in Houtman
Abrolhos (~350 north Rottnest Island) and unlike the exposed fossil corals of the Last
Interglacial (~120ka), such as the fossil reef-building corals of the Rottnest limestone,
as these contain mostly Acropora sp (Playford 1988, 1997).
SAND DUNES
Rottnest Island dunes are part of the Spearwood dune formation of Late Pleistocene
and Holocene eras (~125,000-10,000 years ago) (Newsome 1998; Hearty 2003). The
exposed late Holocene dune and the modern dune are sub-aerial accumulations of
Coastal erosion of cross-bedded Tammal Limestone cliffs at Fish Hook Bay, Rottnest Island
Bi-valve erosion within a solution pipe Rhizolith within Tamala
Limestone
11
eroded and weathered Tamala Limestone (Playford, 1988). The dunes consist of
calcium carbonate minerals, quartz sand and various molluscan fragments (Playford
1997). The dunes form a relatively shallow layer over the Tamala limestone and sand
dunes are seen where there is little vegetation.
SALT LAKES & SWAMPS
The salt lake system on Rottnest Island (Figure 6) is thought to have formed from
natural depressions or dolines of old cave systems that collapsed when sealevels were
lower during the Pleistocene epoch (Playford, 1988). Similar salt lakes that have
formed in this way are seen in other regions of Western Australia, including Noon Reef
in the Houtman Abrolhos some 350km to the north of Rottnest (Playford, 1988). The
salinity (high percentage/amount of dissolved salts) of the lakes is much higher that
the ocean water (~35,000mg/L), and during the summer salinity ranges from
~150,000mg/L (Government House Lake) to 68,00mg/L (Lake Timperley) (Playford
1988). The high salinity of these lakes is associated with thick sediments and an algae
layer, even though they are located only metres from the ocean. It is thought that the
algae layer and the thick mud on the bottom, act as sealant for the lakes, allowing little
ground water ground water flow (Playford et al. 1977; Backhouse 1993). The shallow
depths and combined with low annual rainfall and high annual evaporation contributes
to the maintenance of lake salinity. However, Lake Serpentine, Government House
Lake and Lake Herschell are less saline due to the fresh water springs and rainfall
runoff (Playford et al. 1977).
Some of the lakes have been used for commercial salt production, peat/marl mining
for road building, and Government House Lake was once a fashionable swimming
destination. It does, however, provide the opportunity to view living cyanobacteria
(Stromatolites) (Playford 1988). The remaining three of the once eight fresh to
brackish swamps on Rottnest Island, are important water sources for birds and
wildlife. The sand dunes along Salmon Bay Swamp demonstrate the first stages of the
calcification processes in the formation of rhizoliths (Playford 1988).
12
FIGURE 6: AERIAL PHOTOGRAGH IMAGE AT 0.1 M PIXEL RESOLUTION OF THE LAKE SYSTEM ON ROTTNEST
ISLAND, WESTERN AUSTRALIA. IMAGE (RIA 2010)
STROMATOLITES
The saline lakes of Rottnest Island provide ideal conditions for ancient life forms that
date back to the Precambrian, known as stromatolites (Playford 1988; McNamara
2009b). These living organosedimentary (lithified organic matter) rock-like structures
are crystalized calcium carbonate (aragonite) structures built up by benthic microbial
communities of sediment-trapping, slime-producing, photosynthesizing bacteria and
algae (Geological Survey of Canada 2008; McNamara 2009a, 2009b). It is believed that
the photosynthesizing cyanobacteria found in living Stromatolites, which resemble the
ancient life forms, are responsible for producing the oxygen that gave rise to
subsequent life on earth (McNamara 2009a).
Fossil stromatolites dated back to 3.5 billion years have been found throughout
Australia (e.g. Pilbara region of Western Australia) and living stromatolites are present
around the world (e.g. Bahamas, Canada, Turkey) (Ohmoto 2005; McNamara 2009a).
McNamara (2009a) has shown that living ~3000-4000 year old stromatolites have been
found in Hamlin Pool at Shark Bay. The stromatolites in the salt lakes on Rottnest
Island are believed to be around the same age as the Lake Thetis stromatolites within
13
the Namburg National Park which are ~2000-3000 years old (Grey et al. 1990). Benthic
microbial stromatolitic structures are also seen around the world, generally in poor
nutrient, fresh to hypersaline waters, as the structures can be very thin-layered mats
(microbial mats of Rottnest Island), domal or columnar shaped, which can get to ~40m
high in some parts of the world (Lake Van, Turkey) (Kempe, Kazmierczakt et al. 1991).
Large columnar stromatolites have been found in deep fresh water lakes in Canada,
Pavillion Lake, British Columbia, in depths of 16 to 28 metres (Figure 7) (Reid 2012 ).
14
FIGURE 7: IMAGES OF VARIOUS STROMATOLITES AROUND WESTERN AUSTRALIA, A) HAMLIN POOLS, B) LAKE CLIFTON, C) ROTTNEST ISLAND, G & F) PILBARA), D) EXUMA SOUND, BAHAMAS AND E) LAKE PAVILLION, CANADA. WARREN’S (1982) SCHEMATIC DEPICTION ON THE FORMATION OF DOMAL-SHAPED SHAPED STROMATOLITES. SOURCE(S) (OHMOTO
2005; MCNAMARA 2009B; HOVLAND ET AL. 2010; GIBBS 2011; RUTHERFORD 2011; REID 2012 )
Halmlin Pools, Shark Bay, Western Australia. Source (Rutherford, 2011)
Lake Clifton, Western Australia. Source (Rutherford, 2011)
Domal stromatolites at Serpentine Lake, Rottnest Island, Western Australia. Source (Rutherford, 2011)
Exuma Sound, Bahamas.
Source (Gibbs, 2011)
Columnar stromatiolites at 50m depth in freshwater Lake Pavillion, B.C., Canada. Source (Reid, 2012)
Ancient fossil domal stromatolites, Pilbara, Western Australia. Source (Ohmoto, 2005)
Columnar shaped fossil stromatolite, Pilbara Western Australia. Source (McNamara, 2009)
Formation of donal stromatolites located on ground water seapage sites. Source (Warren, 1982 in Hovland et al, 2010)
A B
G
D C
F E H
15
GEOLOGY: SEDIMENTATION STRATIGRAPHY
TAMALA LIMESTONE
Tamala Limestone (Logan et al., 1970 cited in Playford 1997) is the predominant
geological feature of the Western Australian coastal islands and coastline stretching
from Shark Bay down to the south coast (Playford 1988, 1997; Brooke 2001; Copp
2001). Tamala limestone is the remnant of Pleistocene and early Holocene sand dunes
and is composed of windblown (aeolian) shell fragments (molluscan fauna) and quartz
sand that have formed as a result of cross-bed accumulation (Figure 5) and subsequent
cementation processes (Playford 1988, 1997; Lane 2011). The Tamala limestone
demonstrates various strengths of lithification, from weak to strongly cemented, and
contains calcrete layers (calcium carbonate, minerals and debris) (Playford 1988;
Brooke 2001). Fossil soils and fossilized root structures, rhizoliths and solution pipes
are generally found in weakly lithified limestone (Haig 2002; Short 2005). The rhizoliths
(small roots) and solution pipes (large tap roots) are the remnants of root structures
that have decayed due to lime precipitation around the roots of plants that grew on
the original dunes, and now have been replaced by calcium carbonate and clastic
(fragments of rocks, sandstone, debris) limestone (Playford, 1988).
ROTTNEST LIMESTONE
The Late Pleistocene inter-layer of coral reef limestone and shelly calcarenites is the
type-set Rottnest limestone and it is seen between layers of Tamala Limestone
(Fairbridge, 1953 cited in Playford 1997). It is thought to have formed around the last
interglacial period, ~120,000 years before the present, when sea-level was
approximately three or more metres higher than the present day level on Rottnest
(Figure 9) (Playford, 1988). The Rottnest limestone is unique to the island and contains
fossilized Staghorn, Brain and Tubular corals, and cemented mollusc/gastropods
(Playford 1997). The most abundant assemblage of coral species in the Rottnest
limestone is Acropora species, which is not generally seen in water this far south today
16
. Today Acropora coral species are seen further north in warmer waters at the
Houtman Abrolhos Isles (Playford, 1988).
HERSCHELL LIMESTONE
The Herschell Limestone is composed of weakly lithified Holocene marine shell
deposits and lime sand which in places can range from strongly cemented through to
brittle and crumbly (Playford 1988). Herschell Limestone has been divided into two
formations. The type section described by Playford (1988) shows these two formations;
the upper Baghdad member at 0.6m thickness and the Vincent Member below at
~0.55m (Figure 8). Previous research shows that it is abundant in some 220 plus
molluscan fauna species and is believed to have formed in tidal zones when sea-level
was ~2.4 higher than today (Playford, 1988). Some of these mulluscan species are not
seen in the waters of Rottnest Island today.
FIGURE 8: HERSCHELL LIMESTONE STRATIGRAPHIC IMAGE AND DIAGRAM, SHOWING THE TWO LAYERS, THE
UPPER BAGHDAD MEMBER AND THE LOWER VINCENT MEMBER. SOURCE (PLAYFORD, 1988)
Herschell Limestone showing the upper Baghdad layer above the pencil, composed of Katelysia scalarina and
the Vincent member below various bivalve and gastropods. Image source (Rutherford, 2011)
Type diagram of the Herschell Limestone from Herschell Quarry. Source (Playford, 1988)
17
LATE PLEISTOCENE AND QUATERNARY SEA-LEVEL CHANGE HISTORY
The coastal regions of Western Australia, including Rottnest Island, have been
subjected to fluctuating sea-levels throughout geological history, and the
geomorphology, sedimentary deposition and coastal topography of the coastline has
been moulded and shaped by oscillating sea-levels during glacial and inter-glacial
periods (Hassell et al. 1960; Fairbridge 1961; Playford 1988, 1997; Brooke 2001). The
formation and geomorphology of Rottnest Island is essentially a result of the
fluctuations in sea-level over the last 2 million years (late Pleistocene) (Newsome,
1998). Although there is still some debate over the origin of Quaternary sea-level
change for the southwest coast of Western Australia, including Rottnest Island, it is
agreed that influence on sea-level is apparent (Wyrwoll et al. 1995; Hearty 2003;
Brooke et al. 2010). Global research and geological records show that ~120,000 years
ago, during the last interglacial period, sea-level was at its peak at around 6m-9m
higher than it is today (Church and White 2006; Hearty et al. 2007; IPCC 2007b; The
Royal Society 2010; Braganza and Church 2011). Some 20,000 years ago during the last
glacial period, sea-level retreated approximately 120m-140m below present levels
(Braganza & Church, 2011; Playford, 1988; Newsome, 1998). The global sea-level
changes correlate with the deposition of sediments on Rottnest Island, as illustrated by
the modified graph in Playford (1988) (Figure 9).
18
FIGURE 9: SEA-LEVEL CURVE IN RELATION TO LIMESTONE DEPOSITION ON ROTTNEST ISLAND. SOURCE
(PLAYFORD 1988).
Historical Quaternary sea-level fluctuations are evident in the island’s fossil reefs
exposed 2-3m above present sea-level, as seen in the elevated platforms and notches
in the limestone cliffs around the island (Kendrick et al. 1991). Furthermore, geological
features that extend below present sea-level, e.g. the submarine dunes of Tamala
Limestone, fossil roots that extend into the limestone, and the doline holes structures
of the salt lakes, mark the changes in successive sea-levels over the Pleistocene and
Holocene period (Playford 1988, 1997). The Rottnest Island Quaternary sea-level timing
and features correspond to those of other islands (Bahamas, Bermuda) located in
regions at the same latitudinal locations in the world (Szabo 1978; Carew and Mylroie
1997; Vacher et al. 1997).
Specific illustrations of sea-level change on Rottnest Island include the elevated fossil
reefs, elevated platforms and notches, and the shell deposits (beach deposits and salt
lake deposit of the Herschell and Rottnest Limestone). The shell deposits in the lakes
and the deposits found in Lake Herschell and Lake Vincent quarry, which have been
dated to 4800 to 5900 years old, are located approximately 1.3m above present sea-
19
level, suggesting sea-level was about 1m higher than present levels (Backhouse 1993;
Playford 1997). Furthermore, the elevated notches around the island and around the
lakes are consistent with sea-level being ~2.4m higher than present (Playford 1988).
ELEVATED FOSSIL CORAL REEFS
Exposed fossil corals are a predominant interpellation of past sea-level changes in
carbonate settings and are found in many parts of the world (Szabo 1978; Playford
1997; Vacher et al. 2004). Exposed fossil corals from the last interglacial period are
documented in the Bahamas (Chen, Curran et al. 1991; Carew et al. 1997), around
Australia and Western Australia (Kendrick et al. 1991; Greenstein and Pandolfi 2008),
and include exposed fossils located approximately 3 m above present sea-level on
Rottnest Island (Playford 1988). According to Playford (1988), this illustrates that sea-
level would have been much higher than this, possibly three or more metres higher
than today’s levels, since for the coral to have grown to such an extent, the tops of the
coral would have needed to be submerged in metres of water.
ELEVATED PLATFORMS & NOTCHES (EVIDENCE OF SEA-LEVEL CHANGE)
The coastal shoreline of Rottnest (Figure 10) has distinct features that illustrate erosion
processes and fluctuations in sea-level over time. The typical components of the
Rottnest shoreline include a cliff, storm bench, visor, shoreline notch and platforms
with raised calcified rims of Lithothamnion coralline algae (Playford 1997). Generally,
the weakly cemented limestone is found in the cliffs above the splash zone and the
highly cemented limestone is found below the shoreline platform. It is thought that the
precipitation of calcium carbonate, which aids in the cementation processes, is higher
here due to the wetting and drying of the limestone during tidal action (Playford 1988).
Some of the shorelines contain stepped platforms that are terraced and illustrate a
natural cascading feature, as a result of the well-defined rimmed, layered platforms.
20
FIGURE 10: SCHEMATIC DIAGRAM OF THE ELEVATED SHORELINES AND PLATFORMS OF ROTTNEST ISLAND
COASTLINE. SOURCE (PLAYFORD 1988).
SHELL DEPOSITS
Natural shell deposits (Shark Bay, Western Australia, (Bowdler 1990)) or anthropogenic
shell-middens (e.g. Cape York, Queensland Australia (Bailey 1977), Vancouver Island,
Canada) are features frequently found on many coastal environments, and the origin
and anthropogenic nature of these conspicuous deposits are a source of debate
between science disciplines (geology, anthropology, biology). There are shell deposits
of weathered “gastropods Turbo intercostalis” (Playford 1997) found on some of the
headlands around Rottnest Island, and they have been investigated for their possible
Aboriginal origin since the studies of Sommerville (1921) and Teichert (1950) (in Bindon
et al. 1978). Since the island was cut off from the mainland 6,500 years ago, it is now
believed that Rottnest has not been occupied by Aboriginals, except during the period
when it was used as a prison, for some 70 years during the late 1800’s and early 1900’s
(Bindon et al. 1978; Playford 1997). Nevertheless, the debate on shell deposits is
ongoing. The shell deposits of the Rottnest Limestone and Herschell Limestone,
however, are believed to be natural deposits from the Last Interglacial period, when
sea-levels were higher (Playford 1997).
21
THEMES FOR GEO-INTERPRETATION
Palmer & Newsome (2010) recognised opportunities to expand nature-based tourism
by adding a geology aspect to the focus on the island. They further identified four
world class geologic features (interpretative themes) on Rottnest Island which can be
explored through geotourism initiatives; these include, the exposed Tamala limestone,
the well preserved fossils and fossil reefs, stromatolites in the high saline lakes, and
evidence for sea-level change, including the platforms and notches seen along the
shoreline (Palmer et al. 2010).
Although there are limited specific publications on the geology of Rottnest Island, (e.g.
Playford et al. 1977; Playford 1988; Gozzard 1990; Short 2005; Gozzard 2011), this
literature review found that there are a number of interpretative geological themes
that can be explored in the wider content. The literature revealed, as Playford (1997)
suggested, that Rottnest Island’s geological resources provide a significant global and
regional story on fluctuations in sea-level. The key literature review here reveals a
global significance for Rottnest Island in regards to sea-level rise and geological
evidence of high and low sea-levels. This information is useful for determining the
focus of a number of interpretative themes, where the intention is to provide
educational content on the geology of Rottnest Island. This material can then be used
to match the visible geological and geomorphological evidence of the island to
information provided in the development of interpretative products (maps,
guidebooks, visual displays).
Carbonate islands, reefs and atolls within the worlds “carbonate belt” demonstrate
significant geological evidence of the earth’s ever changing climate (Vacher et al.
2004). These carbonate islands will continue to be affected by the impacts of climate
change (rising sea-levels, extreme coastal weather events), as the result of exploitation
(e.g. resource exploration, recreational tourism activities) and development (e.g.
housing infrastructure, port facilities) of these regions (Church et al. 2006; IPCC 2007a).
However, the common geological features provide a foundation to create awareness
22
and educate the public on the importance of geology and how it can be interpreted to
demonstrate the environmental significance of fluctuating climates.
A recent study (Turton, Dickson et al. 2010) found that tourism destinations are not
investing in climate change adaptive strategies, due to the conflicting perception of
climate change impacts. The lack of literature on how climate change will affect
tourism and geotourism, especially in coastal areas, such as Rottnest Island, suggests
that little research has been done into how geotourism opportunities should be used
to plan for global climate change impacts, in regions which are historically affected by
climate and will continue to be affected in the future. This further emphasises the need
to bridge the gaps between geology science and public education. By using geological
themes that are significant to the public and forming a “dialogue between the public
and earth’s history” (Gozzard 2012) through interpretive media and educational
packages attempts can be made to fill the gap in knowledge dissemination to the
public (Reynard 2008).
The remainder of this review briefly draws attention to major geological interpretative
themes that can be introduced into as a geotourism product on Rottnest Island. This
table (Table 2), organises the key literature into the three main themes, sea-level
change, early life on the island and the fragility of the geology.
23
TABLE 2: MAJOR GEOLOGICAL THEMES ON ROTTNEST ISLAND FOR INTERPRETATION DERIVED FROM
LITERATURE ON ROTTNEST ISLAND.
Themes Sub themes Global Significance References
Stories of sea-level change
Fossil Root Channels (rhizoliths, solution-pipes)
Tuart forest –deforestation and reduction of CO
2 , changes to
vegetation cover
(Storr 1963; Bowdler 1990; Playford 1997; Copp 2001; Church et al. 2006; IPCC 2007a; Greenstein et al. 2008)
Elevated fossil corals and elevated platforms and notches in dunes cliffs
Elevation and age correlation to support global Holocene sea-level curve, surface and water temperature paleo-records
(Playford 1983, 1988; Kendrick et al. 1991; Wyrwoll et al. 1995; Playford 1997)
Shell beds & Sediment Stratigraphy
Historical geological processes of the earth and regional climatic indicators.
(Bailey 1977; Szabo 1978; Murray-Wallace and Kimber 1989; Backhouse 1993)
Rottnest Islands connection to the mainland (bathymetry, fossils emu foot, Aboriginal artefacts)
Evidence to support how to plan for future changes in the earth climate. Aboriginal occupation post separation from the mainland (~5.6ka).
(Playford 1988; Richardson et al. 2005; Brooke et al. 2010) (Bindon et al. 1978)
Elevated shore line platforms and notches
Historical global eustatic sea-level change information, planning for climate impact (development and geotourism)
(Fairbridge 1961; Playford et al. 1977; Brooke 2001; Hearty 2003; Hearty et al. 2007; Brooke et al. 2010)
Early life
Stromatolites Early evidence of life on earth and oxygen product
(Grey et al. 1990; Geological Survey of Canada 2008; McNamara 2009a; Hovland et al. 2010)
Salt lakes Connection to mainland and global Holocene sea-level correlations
(Playford et al. 1977; Playford 1988; Carew et al. 1997; Vacher et al. 2004)
Modern corals & past coral assemblages
Climate Change & Ocean temperatures (Leeuwin Current)
(Szabo 1978; Church et al. 2006; Spooner et al. 2011)
Fragility of the geology
Tamala Limestone Erosion & Fragility
Risk assessment & management, planning for climate impacts, and the preservation of significant geologic regions
(Short 2005; Nageswara et al. 2008; Joyce 2010)
Origin of the Tamala Limestone sands
Complete illustration of carbonate sand and shoreline features and aeolinate transport of sediments (Late Pleistocene and Holocene)
(Tapsell, Newsome et al. 2003; Hearty and O'Leary 2008),
24
CONCLUSION
Rottnest Island is a premier local, national and international tourism destination, with a
richness of carbonate geology and associated environmental attributes (e.g. warm
ocean temperatures, warm-temperate climate, tropical marine biota). The island
attracts over 560, 000 visitors annually (RIA 2011), and demonstrates global
significance of geophysical illustrations relating to climate change (e.g. Sea-level
fluctuations, ocean temperature changes, elevated marine fossils). Given the
abundance of geological assets the island has to offer, Pleistocene and Holocene dunes
(Tamala Limestone), stromatolites, fossil corals and classic examples of historical
fluctuations in sea-levels, the development of geotourism based products and
opportunities such as interpretive panels along board walks, geo-tour guide books and
maps, would serve to improve geotourism on the island (Palmer & Newsome, 2010). It
is possible to incorporate geological scientific data into accessible and engaging
information in order to generate public awareness, with the aim of captivating and
educating the visitor about the earth’s processes and conditions that influence global
climate change (Dowling et al. 2010).
25
REFERENCES
Aurousseau, M. and Budge, E.A. (1921). The Terrace of the Swan and Helena Rivers and Their Bearing on Recent Displacement of the Strand Line. Royal Society of Western Australia 7: 24-28.
Backhouse (1993). Holocene Vegetation and Climate Record from Barker Swamp, Rottnest Island, Western Australia. Journal of the Royal Society of Western Australia. 76: 53-61.
Bailey, G.N. (1977). Shell Mounds, Shell Middens, and Raised Beaches in the Cape York Peninsula. Mankind 11(2): 132-143.
Bindon, P., Dortch, C. and Kendrick, G. (1978). A 2500 Year Old Pseudo Shell Midden on Longreach Bay, Rottnest Island, Western Australia. Australian Archaeology 8: 162-171.
Bowdler, S. (1990). Before Dirk Hartog: Prehistoic Archeaological Research in Shark Bay, Western Australia. Australian Archaeology 30: 46-57.
Braganza, K. and Church, J. (2011). Observations of Global and Australian Climate. Climate Change: Science & Solutions for Australia. H. Cleugh, M. Stafford-Smith, M. Battaglia and P. Graham. Collingwood, Victoria, Australia, CSIRO Publishing: 1-14.
Brooke, B. (2001). The Distribution of Carbonate Eolianite. Earth-Science Reviews 55(1–2): 135-164.
Brooke, B., Creasey, J. and Sexton, M. (2010). Broad-Scale Geomorphology and Benthic Habitats of the Perth Coastal Plain and Rottnest Shelf, Western Australia, Identified in a Merged Topographic and Bathymetric Digital Relief Model. Journal of Remote Sensing 31(23): 6223-6237.
Carew, J.L. and Mylroie, J.E. (1997). Chapter 3A. Geology of the Bahamas. Geology and Hydrogeology of Carbonate Islands. Developments in Sedimentology. L.H. Vacher and T.M. Quinn. Florida, USA, Elsevier: 91-139.
Chen, J.H., Curran, H.A., White, B. and Wasserburg, G.J. (1991). Precise Chronology of the Last Interglacial Period: 234u-230th Data from Fossil Coral Reefs in the Bahamas. Geological Society of America Bulletin 103: 82-97.
Church, J.A. and White, N.J. (2006). A 20th Century Acceleration in Global Sea-Level Rise. Geophysical Research Letters 33(L01602): 1-4.
Churchill, D. (1960). Late Quaternary Changes in the Vegetation on Rottnest Island. Western Australia Naturalist 7: 160-166.
Copp, L., Ed. (2001). Geology & Landforms of the South-West. Bush Book. Kensington, WA, Australia, Department of Conservation and Land Management. 72.
Dowling, R. and Newsome, D. (2010). Chapter 1. Geotourism: A Global Activity. Global Geotourism Perspectives. R. Dowling and D. Newsome. London, United Kingdom, Goodfellow Publishers: 1-17.
Fairbridge, R.W. (1961). Eustatic Changes Is Sea Level. Physics And Chemistry Of The Earth. Pergamon, London. (4): 99-185.
Geological Survey of Canada. (2008). Past Lives: Chronicles of Canadian Paleontology, Pethei Stromatolites. Retrieved Oct 20, 2011, from http://gsc.nrcan.gc.ca/paleochron/03_e.php
Gibbs, G. (2011). (Image). Stromatolites Still Alive and Thriving in the Bahamas. Exuma Sound, Bahama stromatolites. Retrieved April, 2012, from http://www.greenantilles.com/2011/04/06/stromatolites-still-alive-and-thriving-in-the-bahamas/,.
26
Gozzard, J.R. (1990). Rottnest Island Environmental Geology. Geological Survey of Western Australia. Environmental Geology, 1:250 000 Map Series. Environmental Geology. Perth, WA, Australia.
Gozzard, J.R. (2011). Wa Coast -Rottnest Island Digital Datasets. Geological Survey of Western Australia. Perth, WA, Australia.
Gozzard, J.R. (2012). Rottnest Island, Western Australias First Geopark. Perth Geological Survey of Western Australia. Presentation to Rottnest Island Authority.
Greenstein, B.J. and Pandolfi, J.M. (2008). Escaping the Heat: Range Shifts of Reef Coral Taxa in Coastal Western Australia. Global Change Biology 14(3): 513-528.
Grey, K., Moore, L.S., Burne, R.V., Pierson, B.K. and Bauld, J. (1990). Lake Thetis Western Australia: And Examaple of Saline Lake Sedimentation Dominated by Benthis Microbial Processess. Australian Journal of Freshwater Research 41: 275-300.
Haig, D.W. (2002). Guidebook for Mid-Conference Excursion:Rottnest Island. International symposium on foreaminifera. February 4-8, 2002, University of Western Australia, Perth.
Hassell, C.W. and Kneebone, E.W.S. (1960). The Geology of Rottnest Island. Department of Geology. Perth, University of Western Australia. Honours.
Hearty, P.J. (2003). Stratigraphy and Timing of Eolianite Deposition on Rottnest Island, Western Australia. Quaternary Research 60: 211-222.
Hearty, P.J., Hollin, J.T., Neummann, C.A., O'Leary, M.J. and McCulloche, M. (2007). Global Sea-Level Fluctuations During the Last Interglaciation (Mis 5e). Quaternary Science Reviews, Elsevier 26: 2090-2112.
Hearty, P.J. and O'Leary, M.J. (2008). Carbonate Eolianites, Quartz Sands, and Quaternary Sea-Level Cycles, Western Australia: A Chronostratigraphic Approach. Quaternary Geochronology 3: 26-55.
Hovland, M., Ruestlatten, H. and Pederson, R.B. (2010). Seepage-Related Stromatolites? Retrieved April 7, 2012, from http://www.geolsoc.org.uk/page7328.html.
IPCC (2007a). Climate Change 2007: Synthesis Report, Summary for Policymakers. Key findings and uncertainties contained in the working group contributions of the Fourth Assessment Report. I.P.o.C. Change. Geneva: 22.
IPCC (2007b). Climate Change 2007: Synthesis Report. Intergovernmental Panel on Climate Change. Contribution of Working Groups I, II and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Core Writing Team, R.K. Pachauri and A. Reisinger. Geneva: 1-104.
Jacobs, K., Nannup, N. and Revell, G. (2008). Rottnest Island (Wadjemup) Coastal Walk Trail: Concept Plan. G. Macgill. North Fremantle, Western Australia, Prepared by Ecoscaped Australia for, The Government of Western Australia, Rottnest Island Authority.
Joyce, E. (2010). Australia’s Geoheritage: History of Study, a New Inventory of Geosites and Applications to Geotourism and Geoparks. Geoheritage 2(1): 39-56.
Kempe, S., Kazmierczakt, J., Landmann, G., Konuk, T., Reimer, A. and Lipp, A. (1991). Largest Known Microbialites Discovered in Lake Van, Turkey. Nature 349(6310 ): 605-608.
Kendrick, G.W., Wyrwoll, K.-H. and Szabo, B.J. (1991). Pliocene-Pleistocene Coastal Events and History Along the Western Margin of Australia. Quaternary Science Reviews 10(5): 419-439.
Lambeck, K. and Nakada, M. (1992). Constraints on the Age and Duration of the Last Interglacial Period and on Sea-Level Variation. Nature 357: 125-128.
Lane, P. (2011). Geology of Western Australia's National Parks: Geology for Everyone. Margaret River, Western Australia. 108.
27
Masselink, G. and Hughes, M.G. (2003). Introduction to Coastal Processes and Geomorphology. London, Arnold, Hodder Headline Group.
McNamara, K. (2009a). Stromatolites. Whelshpool, WA, Western Australia Museum. McNamara, K. (2009b). Stromatolites -Great Survivors under Threat. Geoscientist 19(12): 16-
22. Murray-Wallace, C.V. and Kimber, R.W.L. (1989). Quaternary Marine Aminostratigraphy: Perth
Basin, Western Australia. Australian Journal of Earth Sciences 36(4): 553-568. Nageswara Rao, K., Subraelu, P., Venkateswara Rao, T., Hema Malini, B., Ratheesh, R.,
Bhattacharya, S., Rajawat, A. and Ajai, A. (2008). Sea-Level Rise and Coastal Vulnerability: An Assessment of Andhra Pradesh Coast, India through Remote Sensing and GIS. Journal of Coastal Conservation 12(4): 195-207.
Newsome, D. (1998). Brief Geological History of the Region around Perth, Western Australia. Perth, School of Environmental Science, Murdoch University.
Newsome, D. and Dowling, R. (2010). Geotourism: The Tourism of Geology and Landscape Oxford, Goodfellow.
Ohmoto, H. (2005). Evolution of Atmospheric O2, Climate, and Biosphere. Astrobiology Life in the Universe, Nasa Astrobiology Institute. Retrieved April, 2012, from http://astrobiology.nasa.gov/nai/library-of-resources/annual-reports/2005/psu/projects/evolution-of-atmospheric-o2-climate-and-biosphere-ohmoto/.
Palmer, S. and Newsome, D. (2010). Ecotourism on Rottnest Island: A Review of the Current Status and Opportunities Perth, Western Australia, Murdoch University: 22.
Playford, P.E. (1976). Rottnest Island: Geology and Groundwater Potential, Western Australia Geological Survey Records, 1976/1977
Playford, P.E. (1983). Geological Research on Rottnest Island. , Western Australia Geological Survey Research Report. 66. 10-15. 66: 10-15.
Playford, P.E. (1988). Guidebook to the Geology of Rottnest Island, Geological Society of Australia (WA division).Geological Survey of Western Australia. 1-67. 1-67.
Playford, P.E. (1997). 27. Chapter 27 Geology and Hydrogeology of Rottnest Island, Western Australia. . Geology and Hydrogeology of Carbonate Islands. L.H. Vacher and T.M. Quinn, 2004, Elsevier. 54 783-810.
Playford, P.E. and Leech, R.E.J. (1977). Geology and Hydrogeology of Rottnest Island. Perth, Australia, Geological Survey of Western Australia. 1-98.
Reid, D. (2012 ). (Image). Introduction to the Pavillion Lake Research Project. Lake Pavillion Research Project Retrieved February 4, 2012, from http://www.pavilionlake.com/.
Reynard, E. (2008). Scientific Research and Tourist Promotion of Geomorphologica Heritage. Geogr. Fis. Dinam. Quat 31: 225-230.
RIA (2010). Rottnest Island GIS Digital Database. Fremantle, WA, Australia, Distributor, Murdoch University.
RIA (2011). Rottnest Island Annual Report 2010-2011: Celebrating 100 Year of Tourism 1911-2011 Fremantle, Western Australia.
RIA. (2012). Rottnest Island Authority Home Page. Retrieved August 5, 2012, from http://www.rottnestisland.com/rottnest-island-authority.
Richardson, L., Mathews, E. and Heap, A. (2005). Geomorphology and Sedimentology of the South Western Planning Area of Australia: Review and Synthesis of Relevant Literature in Support of Regional Marine Planning. A.G. Geoscience Australia, Geoscience Australia, Records 2005/17,: 1-124.
Rutherford, J. (2011). Stromatolites Images of Western Australia
28
Semeniuk, V. and Searle, D.J. (1987). Beach Rock Ridges/Bands Along High-Energycoast in Southwestern Australia: Their Significance and Use in Coastal History. Journal of Coastal Research 3(3): 331-342.
Short, A.D. (2005). Beaches of the Western Australian Coast: Eucla to Roebuck Bay. Sydney, Australia, Sydney University Press.
Sommerville, J.L. (1921). Evidence of Uplift in the Neighbourhood of Perth. Royal Society of Western Australia 6: 5-20.
Spooner, M.I., Deckker, P.D., Barrows, T.T. and Fitfield, L.K. (2011). The Behaviour of the Leeuwin Current Offshore Nw Australia During the Last Five Glacial–Interglacial Cycles. Global and Planetary Change 75: 119-132.
Storr, G.M. (1963). Some Factors Inducing Change in the Vegetation of Rottnest Island. Western Australia Naturalist 9: 19-22.
Syrinx (2010). Coastal Walk Trail: Stage 2 Site Development Plan for Rottnest Island Authority. RPT-1002-001. Syrinx Environmental Pl. Perth, Western Australia.
Szabo, B.J. (1978). Uranium-Series Age of Coral Reef Growth on Rottnest Island, Western Australia Marine Geology. Elsevier Scientific 29: M11-M15.
Tapsell, P., Newsome, D. and Bastian, L. (2003). Origins of Yellow Sand from Tamala Limestone on the Swan Coastal Plain, Western Australia. Australian Journal of Earth Sciences 50: 331-342.
Teichert, C. (1950). Late Quaternary Changes of of Sea-Level at Rottnest Island, Western Australia. Royal Society Proc. Victoria 59: 63-79.
The Royal Society (2010). Climate Change: A Summary of the Science. S.p. centre. London: 1-16 Turton, S., Dickson, T., Hadwen, W., Jorgenson, B., Pham, T., Simmons, D., Tremblay, P. and
Wilson, R. (2010). Developing an Approach for Tourism Climate Change Assessment: Evidence from Four Contrasting Australian Case Studies. Journal of Sustainable Tourism 18(3): 429-447.
Vacher, L.H. and Quinn, T.M. (2004). Geology and Hydrogeology of Carbonate Islands. Develoment in Sedimentology, Elsevier. 54: 948.
Vacher, L.H. and Rowe, M.P. (1997). Geology and Hydrogeology of Bermuda. Geology and Hydrogeology of Carbonate Islands. Developments in Sedimentology. . L.H. Vacher and T.M. Quinn. Florida, USA, Elsevier. 54: 35-89.
Wyrwoll, K.-H., Zhu, Z., Kendrick, G., Collins, L. and Eisenhauer, A. (1995). Holocene Sea-Level Events in Western Australia: Revisiting Old Questions. Journal of Coastal Research 17: 321-326.
93
Appendix 2
Table 1: Data collection form for field investigation of site of geological interest.
Date Regional Location Rank (#) Comments
Site # Site Name Vis Landscape 5 3 1
Latitude Longitude Vis Attributes 5 3 1
Satellite image of site general location
Access 5 3 1
Hazard/Risks 5 3 1
Human Vulnerability
Erosion Vulnerability
5 3 1
5 3 1
Env. Sensitivity 5 3 1 0
Vegetation 5 3 1
Infrastructure 1 0
Stromatolites 1 0
Sea-level Change 1 0
Rhizoliths 5 3 1 0
Fossil (Coral) 1 0
Shell Deposit 1 0
Salt Lakes 1 0
Eolian Morphology 1 0 Limestone (LS) x-bedding, LS Fossil, LS Shell beds, LS Rhizoliths
Limestone Exposure 1 2 3 1=Tamala Limestone (LS) 2=Rottnest LS 3=Herschell LS
Photo #’s photos taken
General Comments
Ranking
For criteria with: 1 & 0 (1=Yes, 0=No or No Evidence) and for
Rhizolith 1=minimal exposure
1, 3, 5 (1= poor, low or ground (veg) & degraded (Vis Land); 3= med,
moderate, Shrub (veg) and modified (Vis Land); 5=good, hard, high,
trees (veg) and natural (Vis Land)
94
Appendix 3
Table 2: Evaluation criteria for assessing sites of geological interest in the field, based on the sites conditions regarding access, management and geology.
Access & Management
Criteria Evaluation Criteria Definition Ranking Rating Definition
Visual landscape (Aesthetic quality)
Indicates if the site is a: Seascape, Coastal View-scape or Island View-scape. And if the view-scape is natural or has been modified by human infrastructure
Natural 5 Natural=cliff & dunes Modified=with infrastructure (tourism facilities, roads) Degraded=natural view has been changed
Modified 3 Degrade 1
Visual Attribute Geosite obstructed or view of site obstructed. Site clearly distinguished and easily recognisable or not easily recognisable.
Good 5 Good = recognisable & clearly noticeable Med = recognisable but poorly visible Poor = eroding/damaged/graffiti
Med 3 Poor 1
Accessibility Ability to access the site. Take note of the site condition, trail or lack of trail, shelter, proximity to road, bus stop and obstruction to the site. Access site by foot, bike or bus? Note: Access may not be good thing for the site.
Easy 1 Easy = close to stop ≤ 50m walk Med = managed trail need to walk ≤ 200m Hard = dirt track or no trail Med 3
Hard 5
Hazard Erosion/Cliff hazards (crumbling limestone) Weather conditions (strong wind & exposure to elements) Trampling risk (heavy traffic to or at site could damage site or surrounding area): Uneven path or beach path
High 5 High = not suitable hazard very frequent (no signage) Med = limited frequency of hazard (minimal or faded signage) Low = very low risk
Med 3 Low 1
Vulnerability 1) Human impact (based on sites level to be susceptibility to be impacted and look for evidence of informal trails, trampling, ability for increased collection, damage) 2) Susceptibility to Natural Erosion (Limestone erodible)
High 5 High = high traffic area and evidence of impacts Med = medium traffic area and evidence of impact Low = Little or no traffic and evidence of impacts Note: need to note the type of impact
Med 3 Low 1
Environmental Sensitivity
Birding nesting grounds or fauna habitat (Quokka foraging) Vegetation cover (lake salt bush or trees) Dune Rehabilitation
Extreme 5 Extreme = No go area Moderate = seasonal exclusion (flora & fauna) Low = very little disturbance to environ conditions Moderate 3
Low 1
Vegetation Coverage of vegetation in respect to large trees, med shrubs and low lying flora. Note vegetation if it obstructs or provides shelter at the site locale (This is a simplistic classification of vegetation)
Trees 5 Tree = Large tree coverage Shrubs = Coastal health Ground = low lying ground coverage Shrubs 3
Ground 1 Infrastructure Existing buildings, roads, bus stops, trails or proposed trails, water
stations and toilet facilities. Cultural significance (Aboriginal occupation)
Yes 1 No 0
Geology Criteria Definition Ranking Rating Definition Stromatolites Presence of and the ability to see. Note the condition if needed Yes 1
95
No 0 Sea-level Change Evidence of sea-level change: Cliff with platforms, notches and visors
Elevated shoreline features Serpulid crust
Yes 1 No 0
Rhizoliths Level of Exposure for Root channels & rhitholiths (fossil root structures) embedded in the limestone
Extensive 5 Extensive exposure= visible, abundant, clearly defined Moderate exposure=visible, defined sparse Minimal exposure=visible and sporadic No Evidence=no visible structures
Moderate 3 Minimal 1 None 0
Fossil (coral) Fossil coral (FC)
Yes 1 No 0
Shell Deposits Shell deposit (natural or from birds and in the Limestone (Rottnest Limestone, Herschell limestone). Indicate on the individual site sheet
Yes 1 No 0
Salt Lakes Part of the lake system and swamps. Yes 1 Note the absence and distinguish between swamps and lakes No 0
Zone of Interest Site that may be of interest for Geotourism (indicate on each sheet) Yes 1
Eolian Morphology Key features of carbonate geology (Limestone)
Clearly defined beds of Eolianate (Cross-bedding) Yes 1 Yes=distinct cross-bedding No = no cross-bedding No 0
Eolianate LS with Shell Bed & Paleosol (fossilized soils and sediments)
Yes 1 Note: each of these on the individual sheets and for sites that do not show any of the key features (e.g. dune systems) indicate “No Key Features with ‘0’ in this section”
No 0 Eolianate LS with deposits of Reef complexes Yes 1
No 0 Eolianate LS with rhizoliths and solution pipes
Yes 1 No 0
Limestone Exposure (present condition)
Aeolian limestone (angled cross-bedding cliffs) Tamala Limestone Rottnest limestone Herschell limestone (Bagdhad & Vincent Membrane) Comment on the condition of the limestone (weathered, eroded)
TLS 1 TLS = presence of Tamala limestone RLS = presence of Rottnest limestone HLS = presences of Herschell limestone None= no specific features (Dune or Beach)
RLS 2 HLS 3 None 0
96
Appendix 4
Table 3: A summary of the major geological features found at the 63 field geosites surveyed during the field studies, showing the geosites regional location, name and geospatial location on Rottnest Island.
REGIONAL LOCATION SITE
NAME EASTING NORTHING GEOLOGICAL ATTRIBUTES
Government House Lake CZ_S1 362029 6458638 Introduction to the island's lake system: Holocene sea-level change -Herschell Limestone, Stromatolites
Government House Lake CZ_S2 361714 6458627 Stromatolites (1.5m below surface), Herschell Limestone, eolian bedding planes, Sea-level change (elevated notches)
Herschell Lake CZ_S3 361553 6458916 Herschell Limestone, Fossil foot prints, Sea-level change (shell deposits). Discuss opportunities: Lake salinity, seasonal bird nesting
Government House Lake CZ_S4 361498 6457608 East end of Causeway: Holocene sea-level history, elevated platforms above intermediate and lower level notches. Serpulid layers encrusted in the Tamala Limestone outcrops
Herschell Lake Quarry CZ_S5 360805 6559208 Mt Herschell Quarry showing the Baghdad & Vincent Members of the type-set Herschell Limestone, Sea-level change history
Lake Vincent/Herschell Lake CZ_S6 360704 6458968 Holocene sea-level change history; double notches, serpulid encrusted limestone, strongly lithified Herschell Limestone
Lake Vincent CZ_S7 360426 6458945 Holocene sea-level change history: Elevated, double notches, collapsed caves and exposed lithified Herschell Limestone
Herschell Lake CZ_S8 360438 6458727 Lithified or calcarinite algal mat-like features along the lake edge
Lake Vincent/Herschell Lake CZ_S9 360199 6458603 Directional marker site: No significant geological features. GPS position taken from RIA GIS dataset, 2010.
Lake Vincent CZ_S10 359633 6458551 Lake system and microscopic algae; Shell deposits of the lithified Herschell Limestone along the lake edge
Pink Lake CZ_S11 359552 6458476 Lake salinity, benthic lake habitat (natural sealant), pink algae (Dunaliella salina), and shell fragment (Vincent Member)
Bulldozer Swamp CZ_S12 359719 6458260 Swamp deposits of lime sand and organic debris; brackish water and large Tuart Trees (no significant geology)
Serpentine Lake (west end) CZ_S13 360198 6457860 Stromatolites and algal mats
Serpentine Lake (south side) CZ_S14 360875 6458161 View northern shoreline Serpentine Lake: Sea-level change (elevated platforms and notches), shell deposits and algal mats
Government House Lake CZ_S15 361394 6458334 Peninsula separating Serpentine & Government House Lake (Quarry): Sea-level change -Exposed Herschell Limestone (Vincent and Baghdad Members); double notches and honey comb weathering
Serpentine Lake (north side) CZ_S14_A 360542 6458211 Holocene sea-level change (upper-level platforms, lower & intermediate level notches, encrusted Serpulid tube worms layers on the Tamala Limestone, Stromatolites, and Limestone cliffs set back from the lake shoreline
Mable Cove Haward Cape NZ_S1 354536 6456189 Eagle Bay: eolian morphology (cross-bedding, natural marine weathering and erosion of Tamala Limestone and storm benches
Mable Cove Turn around NZ_S2 354616 6456558 Eolian morphology -steep eolian bedding planes, marine karst weathering, weakly lithified limestone cliffs
Conical Hill NZ_S3 355311 6455521 Conical Hill: Inland site demonstrating dune morphology and Tamala Limestone outcrops in a vegetated dune landscape
Margorie Bay NZ_S4 355384 6455706 Eolian morphology (cross-bedding, weakly lithified Tamala Limestone and large undercutting into the shoreline cliffs
Abraham Point NZ_S5 355439 6455831 Abraham Point: secondary view-scape site demonstrating the island coastline and dune morphology
Lady Edeline Beach NZ_S6 355752 6455711 Eolian morphology -cross-bedding at Abraham Point : opportunity to discuss formation of Narrow Neck in regards to Sea-level change
Lady Edeline Beach NZ_S7 356665 6455940 Limited exposure of eolian cross-bedding, fragile and weakly lithified Tamala Limestone
Stark Bay NZ_S8 357076 6457832 Transition zone from dune morphology to rocky headlands: Coastal eolian morphology -large extended platforms & storm benches, marine karst weathering, weakly lithified eolian limestone and shell deposit
Crayfish Rock NZ_S9 357265 6458353 Excellent representation of rhizoliths, shell sand deposits (possibly Rottnest Limestone), sea-stacks and weathered eolian limestone
Catherine Point NZ_S9a 357576 6459155 Good demonstration of eolian cross-bedding
Charlotte Point NZ_S10 358005 6459048 Foredune plain and 20m high Tamala Limestone eolian bedding
Charlotte Point Bus Stop NZ_S11 358154 6459155 Eolian morphology -cross-bedding, Transition zone from rocky headland to dune morphology
Little Armstrong Bay NZ_S12 359194 6458902 Coastal view-scape: Eolian morphology -cross-bedding, notches, visors and elevated storm benches, karst marine weathering, natural and induced weathering and paleosols (fossil soils)
Parekeet Isand NZ_S13 360260 6459686 Eolian morphology -cross-bedding, limestone under-cutting and sea-stacks
Little Parakeet Bay NZ_S14 360900 6459202 Illustration of dune erosion, limestone fragility, marine karst weathering and eolian cross-bedding
97
REGIONAL LOCATION SITE
NAME EASTING NORTHING GEOLOGICAL ATTRIBUTES
Geordie Bay NZ_S15 360403 6458887 Small Cove in Geordie Bay: Eolian cross-bedding, deep under-cutting and rhizoliths
Geordie Bay NZ_S16 360566 6458704 View-scape site of lake system: Opportunity to interpret the relationship to the inland lakes and the marine environment
Fays Bay NZ_S17 361188 645976 Fays Bay/Point Clune: Excellent eolian cross-bedding planes and marine karst weathering in Tamala Limestone
East Longreach Bay NZ_S18 361606 6459366 Eolian morphology -bedding planes, erosion and marine karst weathering
The Basin NZ_S19 361872 6459308 Modern shoreline features with reef platforms, sea-stacks and marine weathering in the Tamala Limestone shoreline
Bickley Bay SZ_S1 363687 6458326 Eolian morphology -cross-bedding, marine karst weathering and steep sloped dune sands; Site is not recommended for Geotourism
Bickley Bay SZ_S2 363421 6457759 Geological features are not well represented, due to natural erosion of the limestone and dune sands. Eolian bedding planes are hard to recognize and old signage has fallen down the cliff on the north side; Not a recommended site for Geotourism
Bickley Bay SZ_S3 363393 6457634 View-scape geosite, demonstrating the connection to mainland. Limited geology at GPS location, coastal region provide eolian bedding planes and calcrete layers.
Bickley Bay SZ_S4 363242 6457393 Eolian morphology -cross-bedded plains, rhizoliths, concaved calcrete hardening on beach shoreline
Henrietta Rocks SZ_S5 362236 6457207 Geological interpretation on the connection to the mainland. Good view of Garden and Carnac Island
Old Gunnery SZ_S6 361092 6456545 Tree Hill/Old Gunnery: Binocular viewing site of the island topography and geological formations
Parker Point SZ_S7 361020 6456069 Eolian morphology -cross-bedding, calcarinite Tuart root channels, marine karst weathering (honey-comb patterns in limestone) and calcarenite plaster on Tamala Limestone
Jennies Lookout SZ_S8 360890 6455754 Binocular view-scape site. Eolian morphology -cross-bedding, under-cutting, notches, marine karst weathering and erosion. Good example of weathered sea-stacks. Hazard management is in place.
Little Salmon Bay SZ_S9 360729 6455898 Well-defined calcrete layer on the limestone rocks, solution channels with some calcrete intrusions, honey-comb marine weathering
Parker Point SZ_S10 360455 6455951 Osprey Site/Parker Point Loop Road: Carbonate shoreline erosion -deep under-cutting into the limestone cliffs, containing rhizoliths, solution channels, limestone pillars and shell beach deposits
Salmon Bay Bus Stop SZ_S11 360422 6456208 Well managed site with formal access to Salmon Bay beach. Examples of honey-comb weathering, calcrete layers in solution channels in beach outcrops of marine weathered Tamala Limestone
Fairbridge Bluff SZ_S12 359736 6456934 Fossil corals, large Tuart root channels and calcrete plaster layer on limestone and corals. Rottnest Limestone and fossil coral fragment
Salmon Bay West SZ_S13 359071 6457221 Eolian morphology -cross-bedding, storm benches, notches and visor in the ~8 metre cliffs
Salmon Bay West end SZ_S14 358578 6457063 Carbonate shoreline erosion and weathering -deep under-cutting in the Tamala Limestone
Green Island SZ_S15 358198 6456816 Eolian morphology -cross-bedding, marine weathering and notches and visors on Green Island.
Kitson Point Sanctuary Zone SZ_S16 357725 6456502 Geologically rich region with extensive representation of rhizolith formations, caves and double notches with fossilized soil layer
Strickland Bay Surf Hut SZ_S17 357272 6456493 Eolian morphology -cross-bedding, large notches/undercutting, reef-platforms and karst honey-comb weathering
Strickland Bay SZ_S18 355974 6456700 Distant view of eolian cross-bedding of the South Point headland, storm bench platforms and beach erosion
Strickland Bay SZ_S19 356194 6455872 View-scape site of Wilson Bay: No significant geology at location
Wilson Bay SZ_S20 356093 6455624 Eolian morphology -high cliffs with well-defined bedding planes of Tamala Limestone, terrace intertidal platforms.
One Post Hill SZ_S21 355459 6455738 Wide paddy-field terraced platforms cut into Tamala Limestone, with deep notches and high visors
One Post Hill SZ_S22 355121 6455549 Natural arch (collapsed sea-cave) eolian bedding planes; paddy-field terraced platforms cut into the Tamala Limestone
Wilson Bay Radar Hill SZ_S23 354741 6455082 Plover nesting site: Eolian morphology bedding planes and extended reef platforms cut into shoreline.
Radar Hill SZ_S24 354577 6455294 Shell deposits, fossilized/calcified soil layers in the dune sands; fragile and crumbly limestone cliff
Radar Hill SZ_S25 354341 6455322 Extensive display of rhizoliths, large solution channels and pillar-type limestone structures; Collapsed cave-like formations with an abundance of rhizoliths and calcified root channels; shell deposit and eolian bedding planes
West End CWT SZ_S26 353671 6455897 Eolian morphology -cross- bedding, calcified soil layers and marine Karst weathering in Tamala Limestone; Osprey nest
West End Cathedral Rocks SZ_S27 353962 6456056 Poor representation of geological features. The main geology is the marine weathering of Cathedral Rock
98
Appendix 5
Figure 1: A collection of photographs showing some of the geological feature and geomorphological processes evident on Rottnest Island.