MDBC Airborne Geophysics Project: Final Reportdata.daff.gov.au/.../BBC_ABARES_MDBC_final.pdfMDBC Airborne Geophysics Project: Data Acquisition and Interpretation –Final Report 5

MDBC Airborne Geophysics Project: Data Acquisition and Interpretation –Final Report

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MDBC Airborne Geophysics Project: Final Report

B i l l a b o n g C r e e k ____________________________

Bureau of Rural Sciences August 2003

Consultancy D 2018

© Commonwealth of Australia 2003

This work is copyright. Apart from any use as permitted under the Copyright Act 1968, no part may be reproduced by any process without prior written permission from the Commonwealth available from the Department of Communications, Information Technology and the Arts. Requests and inquiries concerning reproduction and rights should be addressed to the Commonwealth Copyright Administration, Intellectual Property Branch, Department of Communications, Information Technology and the Arts, GPO Box 2154, Canberra ACT 2601 or at http://www.dcita.gov.au/cca.

The Commonwealth of Australia acting through the Bureau of Rural Sciences has exercised due care and skill in the preparation and compilation of the information and data set out in this publication. Notwithstanding, the Bureau of Rural Sciences, its employees and advisers disclaim all liability, including liability for negligence, for any loss, damage, injury, expense or cost incurred by any person as a result of accessing, using or relying upon any of the information or data set out in this publication to the maximum extent permitted by law.

Postal address: Bureau of Rural Sciences GPO Box 858 Canberra, ACT 2601

Internet: http://www.affa.gov.au/brs


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Executive Summary

The MDBC Airborne Geophysics Project was set up to demonstrate the usefulness of airborne geophysics for the management of salinity at a catchment scale. This was to be achieved by providing substantial airborne geophysical coverage, and on-ground calibration of the airborne data, for areas with perceived salinity problems. Prior to the adoption of this MDBC program several recent studies had identified the increasing potential for the latest generation of airborne geophysics data to provide a basis for improved mapping of sub-surface salt. However it was acknowledged that a more integrated, multidisciplinary interpretation approach combining ground observations and expert hydrogeological interpretations was essential. This new generation mapping and interpretation offers the potential for improved prediction of future salt mobilisation It was also intended to support the MDBC / CSIRO Heartlands Program, which is developing sustainable farming systems for salt-affected land. Therefore, one of the key catchments of the Heartlands Program was selected:

- The upper Billabong Creek catchment around Culcairn in the River Murray catchment of Southern NSW, some 40km east-west and 30km north-south, bounded by latitudes 350 36’ and 350 49’ E and longitudes 1460 36’ and 1470 5’ E (Figure 16, page 29);

The airborne geophysics products specified were airborne electro-magnetics, displayed as conductivity depth images (CDIs) and layered earth inversions; magnetics; and gamma-radiometrics. The Bureau of Rural Sciences (BRS) was also contracted to undertake a drilling program in the Billabong Creek catchment to validate the airborne data. Subsequently, the Goulburn-Broken CMA and Goulburn-Murray Water contracted the BRS to undertake a drilling program at Honeysuckle Creek. The Victorian Geological Survey then used the geophysical logs obtained through this drilling program to re-calibrate the CDI’s as a separate initiative, on their part, to this project. The airborne data are lodged with the MDBC and, also, Geoscience Australia. The bore data are lodged with the MDBC and, also, BRS.

Section 1 presents a preliminary interpretation of the data from the Billabong Creek catchment, salt stores are restricted to less than a third of the area surveyed, comprising: the alluvial terrace of Kangaroo Creek; a shallow clayey blanket in the Simmons Creek sub-catchment; and a deeper sump downstream of Walbundrie in the Billabong Creek alluvium. Based on historical work done by BRS, DLWC and CSIRO, only Simmons Creek contributes significant saline drainage to Billabong Creek. Magnetics reveals prior stream systems that hold significant fresh water reserves. The combination of airborne geophysical techniques affords a three-dimensional perspective, providing new insights into the location of salt in the landscape and its delivery to streams and to the land surface. First, large parts of the landscape are salt-free. Secondly, salt is lodged in various facets of the landscape, and these may be unique to a particular landscape, related more to soil (or regolith) than to geology. Salt is stored in clays, whilst the conduits that carry groundwater (and salt) through the landscape are interconnected sands and gravels: commonly current and prior stream beds and alluvial fans; sometimes thick, coarse-textured colluvium. Mobilisation of this salt can now be addressed by hydrogeological modelling using the 3-dimensional framework. Management options identified with greater confidence; and the precise areas where this management is required can be specified. The economic and social implications are profound. Cost is a key issue. At current prices for airborne geophysical survey and drilling, the kind of information provided for the areas overflown in the Billabong Creek and Honeysuckle Creek catchments can be provided at a cost of $5/ha. But once the nature and patterns of salt stores and conduits are established for key areas with the full range of airborne geophysics and ground calibration, this knowledge can be extrapolated to the wider landscape using existing information that often includes airborne magnetics as demonstrated in Steps in Solving Salinity Braaten et al (2002). In this way, management recommendations for whole catchments may be developed at a cost of the order of 50cents/ha. With this information, effective management can be applied rationally to the areas where it will be effective, rather than to whole landscapes or to those areas where opportunity happens to arise. Airborne data as collected for this project may be used at both the catchment and farm scale, since the line spacing used may be translated to maps at 1:25 000 scale without loss of detail, although farm-level planning will require the appropriately detailed level of interpretation.


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Detailed specifications are included with full meta-data in Appendix 1, Billabong Creek. In the first instance, the contractors using standard algorithms processed the airborne data. Drilling was undertaken to calibrate the airborne data and to provide samples for laboratory determination of salts. The down-hole geophysical data and laboratory measurements are presented in Appendix 2, Billabong Creek.

Acknowledgements

The Murray Darling Basin Commission commissioned the airborne surveys and the drilling program at Billabong Creek. The BRS Salinity Team acknowledges, in particular, the direction provided by Mr Scott Keyworth and Mr Bob Newman of the MDBC. Goulburn-Broken Catchment Management Authority and Goulburn-Murray Water commissioned calibration drilling at Honeysuckle Creek, on the initiative of Mr Phil Stevenson and Mr Stephen Feiss, respectively. Kevron Geophysics and Fugro Airborne Surveys carried out the flying program, with project management and quality control by Geoscience Australia. Drilling was accomplished by Exploration Drilling Pty Ltd under the direction of the BRS team. The Geophysics Section of the Victoria Geological Survey subsequently independently recalibrated the Honeysuckle Creek conductivity depth imaging. Mr Ross Brodie of Geoscience Australia prepared the initial airborne data for a review by all stakeholders in October 2001. We acknowledge the scientific input freely given at that time by Mr Dave Gibson, Dr Andy Green, Mr David Heislers, Mr Richard Lane, Mr Richard McEwan, Dr Tim Munday and Mr Alan Willocks. Tim Munday also convened a further stakeholders meeting in May 2002 to plan the calibration-drilling program. Dr Hamish Cresswell, Dr Mirko Stauffacher and Dr Pauline English of CSIRO have given valued input to the interpretation of the Billabong Creek data. Mrs Aleksandra Plazinska, Mr John Spring and Mr John Jaycock carried out the laboratory determinations. Mr Dom Galloway prepared the figures for publication and Ms Kerrie McQuaid and Mr Ian Mullen undertook the text layout.


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CONTENTS

Executive Summary .......................................................................... 3

Acknowledgements ........................................................................... 6

Contents .......................................................................................... 7

Figures ............................................................................................ 8

Tables ............................................................................................. 8

1. Interpretation: Billabong Creek .................................................. 9 1.1 Survey area .......................................................................... 9 1.2 Geology ................................................................................ 9 1.3 Validation of AEM models ...................................................... 15 1.4 Airborne electro-magnetics ................................................... 16 1.5 Airborne magnetics .............................................................. 21 1.6 Airborne radiometrics ........................................................... 25 1.7 Geological models & hydrogeological association ..................... 25 Billabong Creek ........................................................................... 31

REFERENCES .................................................................................. 33

Appendix 1: Billabong Creek: Airborne Geophysical Surveys Metadata.. 37 Terms and Conditions ................................................................ 48

Appendix 2: Billabong Creek: Drilling locations, downhole logs and laboratory data ...................................................................... 49

Figures

Figure 1: Example of geological log, BC7 ........................................... 10 Figure 2: Comparison of manual texture with laser grain size analysis,

BC17D .................................................................................. 11 Figure 3: Laser grainsize distribution, BC17D. .................................... 12 Figure 4: Comparison of manual texture with laser grain size analysis,

BC18D .................................................................................. 13 Figure 5: Laser grain size distribution, BC18D .................................... 14 Figure 6: Relationships between conductivity and salt and clay, BC7 ..... 15 Figure 7: Billabong Creek, conductivity 0-5m draped over DEM ............ 17 Figure 8: Billabong Creek, conductivity 10-15m .................................. 18 Figure 9: Billabong Creek, conductivity 30-40m .................................. 19 Figure 10: Billabong Creek, ternary conductivity image showing bore

locations ............................................................................... 20 Figure 11: Billabong Creek, total field magnetics ................................ 22 Figure 12: Billabong Creek, first vertical derivative magnetics showing

bore locations ........................................................................ 23 Figure 13: Billabong Creek, gamma radiometrics ternary image ........... 24 Figure 14: Billabong Creek hydrogeological model .............................. 27 Figure 15: Billabong Creek surface expression and excess water model . 28 Figure 16: Locality Map, Billabong Creek ............................................ 29 Figure 17: Digital elevation model, Billabong Creek ............................. 30 TABLES Table 1: Comparison of texture (averaged over interval) with laser grain

size analysis, BC17D ............................................................... 12 Table 2: Comparison of texture (averaged over interval) verses laser grain

size, BC18D ........................................................................... 14 Table 3: Billabong Creek, conductivity models .................................... 31 Table 4: Billabong Creek, new drill sites ............................................. 32


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1. INTERPRETATION: BILLABONG CREEK Grant Jones, Peter Baker and David Dent Bureau of Rural Sciences

1.1 Survey area Billabong Creek catchment is located between the much larger Murrumbidgee and Murray River catchments in southern New South Wales. Previously, the catchment had been identified as a major contributor of salt to the Riverina but Baker et al. (2001) found waterlogging to be the greater threat in the upper catchment and only modest salt exports, chiefly from the Simmons Creek sub-catchment. The upper Billabong Creek catchment, around Culcairn, has a winter-dominant rainfall pattern with mean values ranging from 680mm in the east to 450mm in the west. Land use is almost equally divided between cropping and grazing. The survey area between Culcairn and Walbundrie (Figure 16) centres upon the broad alluvial plain associated with Billabong Creek. It is flanked by undulating, erosional rises and a few low hills. Surficial materials are diverse: from alluvial sands and silts on the plains to colluvium and weathered granites on hill slopes. There are a few, source-bordering dune sands close to present day drainage channels on the plain.

1.2 Geology Palaeozoic/Mesozoic granites with minor Silurian volcanics dominate the higher parts of the landscape. Devonian meta-sediments also occur in the upper reaches of the catchment. The bedrock outcrops in areas of moderate relief giving way to colluvium on gentler slopes. The alluvial plains are built up from sediments of the Lachlan and Cowra Formations - which host the major aquifers and, also, the salt stores as indicated by the conductivity signatures seen in the aerial survey. Materials observed in bores were logged to provide a geological framework. The interpretations link conductivity patterns to geology and soil/regolith unit, seeking relationships with regional geology and landforms that may enable extrapolation of observed conductivity responses beyond the survey area. In the logging of cores, from air-core and diamond-core drilling, materials were classified as either transported or in situ. Transported sediments and regolith (unlithified, normally consolidated material) are described in terms of an estimated particle size distribution, comprising clay-silt, sand and gravel using the United States Department of Agriculture (USDA) standard In-situ materials are segregated according to the degree of

weathering: saprolite is recorded when more than 20 per cent of weatherable minerals have been altered, and implies weathering has been essentially isovolumetric; saprock is defined as having less than 20% of weatherable minerals altered, and generally requires a hammer blow to break.

Clay- Silt Sand Gravel Figure 1: Example of geological log, BC7 Because the materials are sampled every one metre from air core, the descriptions are only an estimated average over the given depth. Diamond cores, however, were logged undisturbed in their entirety and observed units varied from 10mm to several metres thick. To calibrate or correlate these texture descriptions, laser grain size analysis was conducted from BC17D and BC18D EC 1:5 samples (analysis conducted through Andrew McPherson, ANU). Several samples were collected over consecutive units to compare textures that would be potentially logged in the course of air-core drilling. Results from laser grain size match variations in manual assessment of texture (Figure 2 and Figure 4). Laser analysis (Figure 3 and Figure 5) also details a dominant silty component (2-53um) within the clay-silt fraction.

Saprolite

Saprock Basement


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Clay-Silt Clay-Silt Sand Sand-Gravel Gravel

Figure 2: Comparison of manual texture with laser grain size analysis, BC17D

(b) (a)

(c)

Saprolite

Table 1: Comparison of texture (averaged over interval) with laser grain size analysis, BC17D Laser Grain size Interval m

Laser Clay

Laser Silt

Laser Sand & Gravel

Texture % Clay + Silt

Texture % Sand

Texture % Gravel

(a) 0.8 – 2.5

19.8 60.6 19.6 87.5 12.5 0

(b) 3.5 – 5.8

9.8 51.8 38.4 59 41 0

(c) 8.7 – 10.9

11.4 64.5 24.0 76 24 0

0

5

10

15

20

25

30

35

40

0.00006 0.0039 0.053 0.149 0.42 1.19

Grainsize (um)

%

8.7-10.9 (c)

0.8-2.5 (a)

3.5-5.8 (b)

Figure 3: Laser grainsize distribution, BC17D.

Clay Silt Very Fine Fine Medium Coarse Sands


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Clay-Silt Clay-Silt Sand Sand-Gravel Gravel

Figure 4: Comparison of manual texture with laser grain size analysis, BC18D

(a) (b)

(c)

(d)

(e)

(f)

(g)

SAPROLITE

Table 2: Comparison of texture (averaged over interval) verses laser grain size, BC18D Laser Grainsize Interval m

Laser Clay

Laser Silt

Laser Sand & Gravel

Texture % Clay+ Silt

Texture % Sand

Texture % Gravel

(a) 1.75 – 3.1

20.5 69.7 9.8 92 8 0

(b) 4.7 – 7.3

11.3 58.7 30 83 17 0

(c) 13 – 17.75

6.1 27.2 66.7 40 48 12

(d) 26.6 – 28.1

9.1 60.3 30.6 92.5 7.5 0

(e) 46.5 – 47.2

1.3 15.8 82.9 12 88 0

(f) 52.1 – 54.8

34.7 59.4 5.9 98 2 0

(g) 76.7 – 79.0

7.9 43 49.1 38 60 2

0

10

20

30

40

50

60

70

80

0.00006 0.0039 0.053 0.149 0.42 1.19

Grainsize (um)

%

76.7-79.0 (g)

52.1-54.8 (f)

46.5-47.2 (e)

25.6-28.1 (d)

13-17.75 (c)

4.7-7.3 (b)

1.75-3.1 (a)

Figure 5: Laser grain size distribution, BC18D

Clay Silt Very Fine Fine Medium Coarse Sands


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1.3 Validation of AEM models The initial conductivity models derived from the AEM (Section 2, Table 1) were confirmed. Situations modelled as high conductivity were values above 400 mS/m; medium between 200 and 400 mS/m; and values below 200 mS/m deemed low. A general relationship is observed between a high clay-silt content and elevated conductivity. Thick high models (BC7, BC16D & BC19D) relate to a dominant basal alluvial clay/silt unit, which extends to depths greater than 80m. Conductivity in this unit is a factor of water content and salt, not clay per se. This may be observed in BC7 (Figure 6) where the regression of conductivity against %clay gives an r2=0.39, compared with r2=0.66 against EC 1:5. Previously, Cresswell et al. (2003) have demonstrated very high correlations between detailed down-hole conductivity and the bulk salt content (concentration x total solute volume) of pore fluid.

BC7EC 1:5, Clay-Silt % vs Conductivity mS/m

R2 = 0.3966

R2 = 0.6694

R2 = 0.7423

0

500

1000

1500

2000

2500

0 100 200 300 400 500 600

Conductivity mS/m

EC

1:5

uS

/cm

0

10

20

30

40

50

60

70

80

90

100

Cla

y-S

ilt

%

EC v Cond

EC x Clay v Cond

Clay v Cond

Figure 6: Relationships between conductivity and salt and clay, BC7 All low and shallow high to low models (BC3 & BC8) are dominated by sandy and/or saprolite sequences. Saprolite tends to have a low conductivity signature, except those in volcanic provinces (which have a higher clay content - BC7 & BC16). But low conductivities indicate low salt content, regardless of clay content. In the case of thick colluvial sequences, this uniform, low conductivity reflects a consistent transported unit, whether sandy or clay/silt dominated, which tends to vary little until

it grades into in situ saprolite in which the conductivity tends to be lower still (BC6).

1.4 Airborne electro-magnetics The spatial pattern of conductivity is closely associated with landforms (Figure 40). Substantial salt stores are restricted to three areas Figure 40 and Figure 42):

- The alluvial terrace associated with Kangaroo Creek to the east; - A shallow, triangular blanket over the lower Simmonds Creek sub-

catchment; - A deeper-seated salt store within the main Billabong Creek alluvium

to the west of Walbundrie.

In addition, there are several small, very shallow salt stores that appear only in the 0-5m CDI slice, where salt is held in clayey colluvium on the lower slopes (BC1, BC2).

The pattern is depicted most clearly by the ternary conductivity image (Figure 43) in which relatively high conductivity in the 0-5m layer is coloured blue, the 15-20m layer in green and the 40-60m layer in red. Relatively high conductivity in all three layers becomes white. The ternary image also distinguishes a continuous belt of medium conductivity in the 15-20m layer in the Billabong Creek alluvium, which we interpret as a conduit rather than a store. The Kangaroo Creek Terrace (BC16d, BC7) exhibits high conductivities, in the range 400-600 mS/m, associated with clay/silt alluvial units. Sandy layers exhibit lower values. In the underlying saprolite, there is a secondary peak of conductivity below about 70m, which tapers quickly through the saprock to the resistive basement volcanics. EC 1:5 values follow the down-hole conductivity closely, also distinguishing sandy layers as low salt. The relatively high alkalinity of the pore waters from some of these sandy layers indicates that they are conduits of fresh, surface-derived water. Simmons Creek sub-catchment shows a quite different conductivity pattern that appears to disperse quickly after 10–15m (BC8, 9, 17d). There is no strong landform association, in contrast to Kangaroo Creek. In this case, there may be a surficial component of redistributed, Aeolian silt/clay material in the upper salt-bearing layer. Once again, however, conductivity is dominated by salt-bearing regolith rather than bedrock. The pattern is closely associated with the restricted catchment of Simmons Creek and all drainage is confined to areas of sediment deposition, carrying leached salt out through the small creek and the adjacent prior stream.

MDBC Airborne Geophysics Project: Data Acquisition and Interpretation – Final Report

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Fig

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7:

Bil

lab

on

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con

du

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-5m

dra

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over

DEM

18 MDBC Airborne Geophysics Project Data Acquisition and Interpretation – Final Report

Fig

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8:

Bil

lab

on

g C

reek,

con

du

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ity 1

0-1

5m


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Fig

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9:

Bil

lab

on

g C

reek,

con

du

ctiv

ity 3

0-4

0m


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The Walbundrie Sump in the Billabong Creek alluvium exhibits medium conductance at the near-surface but elevated values below 20m. Bore BC19d confirms this pattern. There is close correspondence between down-hole conductivity and both EC 1:5 and pore fluid EC in the upper (Cowra Formation) alluvium to 50m below surface. Below this the lower (Lachlan Formation) alluvium exhibits medium conductivity associated with clay texture, high water content but low salt content. Within the upper alluvium, low salt is associated with high alkalinity, indicating flushing with surface-derived low salt water. A striking feature in several bores is the high water content and transmissivity of thick colluvium derived from the deeply weathered, granitic, saprolite. Almost universally, this groundwater is low in salt and this is confirmed by the low conductivity values exhibited by the colluvial cover over much of the landscape.

1.5 Airborne magnetics Several prior stream networks can be observed in the total field magnetics image (Figure 44) and these features are emphasised on the first vertical derivative image (Figure 45). Four locations (BC10, BC11, BC12 and BC13) were drilled to elucidate these features; each bore intersecting magnetic signatures of varying intensity and thickness. The large feature, targeted by BC12, shows a thick sandy sequence of moderate conductivity (250mS/m). The dispersed (large) magnetics signature indicates sediments deposited in a broad alluvial system, and potentially further travelled than those identified by smaller signatures. This hole was abandoned due to excess water - which was a good sign for water exploration using magnetics data. The sediments observed in the smaller drainage features were poorly sorted sand and gravel units, intersected from 10 to 30 metres. Water was found only in the deeper unit (BC10), where a mix of sands and magnetic gravels appears to have been deposited by fluvial and sheet-flow processes. These sediments had a strong magnetic intensity derived from Fe-coated nodules and detrital ferruginous sediments, with the major water-bearing zone comprising large (50mm), angular, clean quartz gravels in the middle of the intense magnetic zone at 26m. The shallow, less intense signature above is minor magnetic gravel mixed with sandy clays. The shallow responses in BC11 (10-20m) were large detrital gravels from the surrounding sediments, often highly ferruginous, deposited on the floor of narrow valleys by colluvial processes. This forms the strong, fingering magnetic signatures in the higher parts of the landscape. The gravel is often surrounded by a matrix of strong Fe-coloured silts, which may be Aeolian.


Fig

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11

: B

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bo

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Cre

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tota

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1.6 Airborne radiometrics Figure 46 shows the ternary gamma radiometric image in which the potassium signal is coloured red, thorium in green and uranium in red. A strong signal from all three radioelements becomes white. The most prominent feature of the image is the very intense potassium (red) signal from granite outcrops, notably Goombargana Hill and Mullemblah Hill and the strong thorium-uranium signal from the granite south of Walla Walla. Outcrops of metasediments (siltstone-sandstone) on the NEW-SE trending ridges of the Burrumbuttock Hills and the big ridgebacks that form the neck of the Upper Billabong Creek valley north and south of Culcairn are picked out by in pink. Downslope of the summits and crests, the intense signal from the aprons of locally transported material gives way on the footslopes to a weak (grey) signal that indicates thick, strongly weathered colluvium. The Murray alluvium to the southwest and the Billabong Creek alluvium exhibit distinctive patterns. The radiometrics picks out the intricate pattern of leaves, back swamps and circular ponds, with different mixes of clayey sediment identified by distinctive signals, and flooded ground showing black. (The clay floor of the swamp west of Henty is also picked out by a high-potassium rich signal). The Billabong Creek alluvium appears much more homogeneous, the dull grey signal indicating strongly weathered material, similar to the slope colluvium, with active and recent channels picked out by lighter values. The Kangaroo Creek alluvial terrace, already identified as a salt store, is sharply delineated but the Simmons Creek salt store is not. The only distinguishing feature on the ternary image is a green (high thorium) hue draped over the lower Simmons Creek valley. Its position in the lee of Mullemblah Hill suggests that this may indicate Aeolian material, similar to that mapped further north in the Murrumbidgee and Bland Creek catchments by Wilford et al. (2001). The very sharp differentiation of soil parent materials by this high intensity imagery and combination with the digital elevation model offers an excellent basis for enhanced soil mapping at a scale of 1:25 000. Good use can also be made of some of the associations between salt stores and landform/regolith unit to extrapolate the mapping of salt stores beyond the areas covered by AEM.

1.7 Geological models & hydrogeological association See below Figure 14 and Figure 15. Materials observed during drilling indicate a variation or break in sedimentation within the larger transported unit. An upper (Cowra Formation) and lower (Lachlan Formation) are observed, with the lower formation often thicker and more extensive than previously described. The


Cowra Formation is defined based on poorly-sorted sands and clay sequences and shoestring sands. Its goethite mottling is attributed to wetting and drying through a fluctuating watertable. This mottling is due to water fluctuations and subsequent wetting and drying of the sediments. The base of the unit is often defined by a single, transmissive sand unit. A large (2-3m thick) basal (clean) sand and gravel unit defines the underlying Lachlan Formation. This is very transmissive and is overlain by thick, plastic, dark grey clay, often iron-mottled. This combination forms a potentially confined or semi-confined aquifer system. This aquifer may be seen in the pore fluid analysis with the basal unit having very low salt concentration compared to the upper formation. Three aquifer systems can be deduced from the bore data, with up to four different water levels being produced. The upper formation and lower formation each have one dominant aquifer system. The basal unit of the lower formation is the most transmissive and is under pressure with water levels reaching +8m after drilling at BC16D. There are potentially 2 water levels within the upper formation, the shallowest associated with perched groundwater within the top 5m and the other within the shoestring sandy unit. The perched flux system within the top 5 metres will produce most of the surface expression across the region, especially within Simmons Creek which has a shallow sandy unit along the line of the creek, base-flow driven, and flushing saline groundwater out of the catchment.


27

Figure 14: Billabong Creek hydrogeological model

Saprock to Basement Granite

SIMMONS CREEK CATCHMENT N

Simmons

Walbund

Alluvial

Saprolite

Cowra Formation

Lachlan

Redox Front

Palaeo-Simmons C eek

Shoestring sands Cowra Formations

Lachlan Formation

Highly weathered Saprolite

Saprock grading to basement (Granite)

BC14 & BC18D BC17D

Simmons Creek


Figure 15: Billabong Creek surface expression and excess water model


29

NEW SOUTH WALES

BAIRNSDALE

WAGGA WAGGA

DENILIQUIN

MELBOURNE

ALBURY

WODONGASHEPPARTON

CANBERRA

GEELONG

BENDIGO

BALLARATVICTORIA

144°0'0"E

144°0'0"E

145°0'0"E

145°0'0"E

146°0'0"E

146°0'0"E

147°0'0"E

147°0'0"E

148°0'0"E

148°0'0"E

149°0'0"E

149°0'0"E

39°0'0"S 39°0'0"S

38°0'0"S 38°0'0"S

37°0'0"S 37°0'0"S

36°0'0"S 36°0'0"S

35°0'0"S 35°0'0"S

°

BILLABONG CREEKSALINITY STUDY

GENERAL LOCATION

Legend

Billabong AEM

Billabong Catchment

RoadsHighway

Major Road

Built Up Areas

Waterbodies

Lake

Reservoir

Flood Area

Swamp

Major Watercourse

Streams & Rivers

0 125 250 375 50062.5Kilometers

Figure 16: Locality Map, Billabong Creek


Figure 17: Digital elevation model, Billabong Creek


31

Billabong Creek An initial 15-hole air-core program followed by 4 diamond holes was planned. Bores were completed during March and April 2002, with an additional 2 air-core bores after the diamond program. In total, 18 complete conductivity profiles were obtained with chemistry analysed except for BC9, 12 and 21. Tables 1 and 2 list the conductivity models described prior to drilling and their final positions and depths. Table 3: Billabong Creek, conductivity models Bore Model Geology Estimated

depth, m BC1 Medium to low conductor Sandy clays – escarpment fan 40 BC2 High to low Clay into saprolite (volcanic) 60 BC3 Long low Sands – Billabong creek sediments 100 BC4 Shallow medium to low Clays over saprolite 40 BC5 Medium to low Sands & clays into saprolite 60 BC6 Shallow high to low Sands & clays into saprolite 60 BC7 Long high Dominate clay unit into rock 80 BC8 Shallow high to low Thin sands over saprolite 60 BC9 High, medium to low Sands & clays over saprolite 80 BC10 Minor magnetics Thin cover with gravels –

palaeomagnetic feature 60

BC11 Minor magnetics Very thin cover over rock - gravels 40 BC12 Major magnetics Alluvial sediments sands 60 BC13 Medium to low minor

magnetics Sands & clays over saprolite 40

BC14 High, medium to low Sands and clays 80 BC15 Shallow high to low Clays grading to sands into saprolite 80 BC16d BC7 80 BC17d Shallow high grading to

low Clays over saprolite 50

BC18d BC14 80 BC19d Long high Sands & clays, possible billabong

creek sediments 80


Table 4: Billabong Creek, new drill sites Bore Easting Northing RL (m) End of Hole Reamed End of Log BC1 0503571 6043563 280 60 NO 32.5 BC2 0495788 6045027 211 72 YES 75.6 BC3 0502396 6050743 217 108 YES 90.5 BC4 0498162 6061854 214 36 NO 36.5 BC5 0497477 6061369 221 54 NO 49.3 BC6 0494294 6061039 216 55 NO 52.5 BC7 0495166 6055358 214 62 YES 60.75 BC8 0485768 6059794 209 69 NO 61.9 BC9 0483617 6055378 208 97 YES 96.2 BC10 0470313 6055378 201 78 YES 72.25 BC11 0474293 6033819 224 44.1 NO 42.4 BC12* 0475639 6027896 205 30 NO 12.85 BC13 0471742 6043253 201 72 NO 33.46 BC14* 0479907 6051522 200 96 YES 49.88 BC15 0494602 6053134 218 80 YES 78.4 BC16d 0493835 6054520 215 94.3 YES 93.65 BC17d 0484067 6051230 205 104 NO 104.3 BC18d 0479924 6051517 200 104.2 YES 104.44 BC19d 0471139 6051380 192 104.4 NO 103.93 BC20 0476555 6051372 189 62.2 NO 56.31 BC21* 0476116 6048452 189 71 YES 8

* Incomplete hole, full conductivity profile not obtained (BC21 not attached with report). Also note BC18d (diamond core hole) next to BC14.


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REFERENCES

Allen M J 1996 Method for assessing dryland salinity in Victoria. Centre for

Land Protection Research Technical Report 34, Dept of Natural Resources and Environment, Victoria

Baker PA, Please P, Coram J, Dawes, W, Bond W, Stauffacher M, Probert

M, Huth N, Gaydon D, Keating B, Moore A, Simpson R, Salmon L, and Stefanski A, 2001. Assessment of salinity management options for Upper Billabong Creek catchment, NSW: Groundwater and farming systems water balance modelling. National Land and Water Resources Audit Report.

Braaten R, Baker P and Dent D 2002 Steps to Solving Salinity – A systems

approach to salinity management at Billabung Creek, NSW Canberra Bureau of Rural Sciences

Brodie R, R Lane and D Gibson 2002 Gilmore Project: comparison of AEM

and borehole conductivity data. Unpublished Brown C M and A E Stephenson 1991 Geology of the Murray Basin,

southeastern Australia. BMR Bulletin 235 Cheng X 1999 Goulburn-Broken dryland salinity prioritisation. Centre for

Land Protection Research, Technical Report 58 Cheng X and M Reid 2001 Targeting suitable areas for farm forestry in the

Broken and North Goulburn plains and surrounding uplands. Centre for Land Protection Research, Tech. Rept 65

CLPR 2002 Goulburn Broken Groundwater Flow Systems 1:750 000.

Centre for Land Protection Research, Vic Dept Nat Resources and Environment 18/3/2002

Cook SE, RJ Corner, RJ Groves and G Grealish 1996 Application of

airborne gamma radiometric data for soil mapping. Australian J. Soil Research 43,1,183-194

Cresswell RG, DL Dent RC Brodie and DS Galloway 2003 Calibration of

airborne conductivity surveys for the quantitative determination of salt at a regional scale. Submitted to Soil and Plant Analysis, Marcel Dekkar, New York

Dahlhaus PG, M Reid and X Cheng 2000 Broken and Northern Goulburn

Plain salinity study: salinity processes summary. Centre for Land Protection Research, Technical Report 66


Dent D L, T J Munday, R C Brodie and K C Lawrie 2002 Implications for salinity and land management – Honeysuckle Creek Victoria: a preliminary interpretation of high-resolution airborne geophysical data 223-233 in G N Phillips and K S Ely (eds) Victoria undercover, Benalla 2002, CSIRO, Collingwood

Lane R, A Green, C Golding, M Owers, P Pik, C Plunkett, C Sattel and B

Thorn 2000 An example of 3-D conductivity mapping using the TEMPEST airborne electromagnetic system. Exploration Geophysics 31, 225-235

Lawrence M, R Lane and S Baron-Hay 2001 Acquisition and processing

report, Honeysuckle Creek, Victoria. Fugro Airborne Surveys, FAS Job#903

Mackie TE and M Baccin 1997 Total magnetic intensity (reduced to pole)

with northeast illumination colour pixel-image map of Wangaratta, Victoria, and Scale 1:250 000. Australian Geological Survey Organisation, Canberra

Macnae J and Lamontagne 1987 Imaging quasi-layered conductive

structures by simple processing of transient electromagnetic data. Geophysics 562,545-554

Macnae J, A King, N Stolz, A Osmakoff and A Blaha 1998 Fast AEM data

processing and inversion. Exploration Geophysics 29,163-169 McNeill, J.D., 1986, Geonics EM39 borehole conductivity meter. Theory of

Operation: Geonics Technical Note TN-20. Maher S, A H V Vanderberg, P A McDonald and P Sapurmas 1997 The

geology and prospectivity of the Wangaratta 1: 250 000 map sheet area. VIMP Report 46, Minerals and Petroleum Victoria

Sattel D 1998 Conductivity information in three dimensions. Exploration

Geophysics 29, 1&2, 157-162 Schwertmann U, H Fechter, RM Taylor and H Stanjek 1995. A lecture and

demonstration for students on iron oxide formation, 11 to 14 in GJ Churchman et al. (Editors) Clays controlling environment, Proc. Tenth Int. Clays Conf., Adelaide July 18-23 1993. CSIRO Publishing, Melbourne

Wilford JR, PN Bierwith and MA Craig 1997 Application of airborne

gamma-ray spectrometry in soil/regolith mapping and applied geomorphology. AGSO J. Australian Geology and Geophysics 17,2,201-216


35

Wilford JR, DL Dent, R Braaten and T Dowling 2001 Running down the salt in Australia 2: smart interpretation of airborne radiometrics and digital elevation models. The Land (Ghent) 5,2,79-100


37

Appendix 1: Billabong Creek: Airborne Geophysical Surveys Metadata

ANZLIC IDENTIFIER: ANCW1201001001

TITLE: Billabong Creek Airborne Geophysical Surveys

CUSTODIAN: Geoscience Australia

JURISDICTION: Australia

ABSTRACT: As part of the National Action Plan for Salinity and Water Quality, the Murray Darling Basin Commission (MDBC) commissioned airborne geophysical surveys over the Billabong Creek catchment in New South Wales during 2001. Fugro Airborne Surveys Pty Ltd (Fugro) and Kevron Geophysics Pty Ltd (Kevron) were contracted to undertake the data acquisition and processing of the airborne geophysical data. Their work was contracted through the Bureau of Rural Science (BRS). Geoscience Australia managed and supervised the contractor’s work. Two airborne geophysical surveys were flown using different aircraft and instrumentation. They were; 1. An electromagnetic survey utilising the TEMPEST time domain airborne

electromagnetic system described by Lane et al (2000b). This survey is hereinafter referred to as the AEM survey.

2. A magnetic, gamma-ray (radiometric) and elevation survey utilising an industry standard system (Horsfall, 1997). This survey is hereinafter referred to as the MAGSPEC survey.

The specifications of the AEM survey were; Aircraft: CASA C212-200 Turbo Prop, VH-TEM Flight line spacing: 200 metres Tie line spacing: not flown Flight line direction: east-west Tie line direction: not flown Line kilometres: 5,522 kilometres Nominal flying height: 120 metres above ground level Along line sampling: 0.2 seconds (~12 metres) magnetics

1.0 seconds (~60 metres) GPS 13.333 microseconds streamed AEM 0.2 seconds (~12 metres) stacked AEM


The specifications of the MAGSPEC survey were; Aircraft: Aerocommander Shrike, VH-KAV Flight line spacing: 100 metres Tie line spacing: 1000 metres Flight line direction: east-west Tie line direction: north-south Line kilometres: 34,178 kilometres Nominal flying height: 60 metres above ground level Along line sampling: 0.1 seconds (~7 metres) magnetics

1.0 seconds (~70 metres) gamma-ray 1.0 seconds (~70 metres) GPS

0.1 seconds (~7 metres) altimeter SEARCH WORDS: Geoscience Geophysics Airborne Electromagnetic Magnetic Gamma-ray Radiometric Elevation Salinity Conductivity TEMPEST Billabong. GEN CATEGORY: TO BE INCLUDED BY MDBC GEN CUSTODIAL JURISDICTION: Australia GEN NAME: TO BE INCLUDED BY MDBC GEOGRAPHIC EXTENT POLYGON: 147.081 -35.529, 147.081 -35.971, 146.479 -35.971, 146.479 -35.529. (Note the AEM survey covers a smaller area – see additional metadata) NORTH BOUNDING LATITUDE: -35.529 SOUTH BOUNDING LATITUDE: –35.971 EAST BOUNDING LONGITUDE: 146.497 WEST BOUNDING LONGITUDE: 147.081 BEGINNING DATE: 2001/05/02 ENDING DATE: 2001/09/19 PROGRESS: Complete MAINTENANCE AND UPDATE FREQUENCY: As required STORED DATA FORMAT: DIGITAL – Point located data in ASCII Columns data files with descriptive header files. Gridded data in ERMapper IEEE4Byte Real data files with


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descriptive header files. Data Acquisition and processing reports compiled by contractors. NON-DIGITAL – Hard copy – Data Acquisition and processing reports compiled by contractors. AVAILABLE FORMAT TYPE(S): DIGITAL - Point located data in ASCII Columns data files with descriptive header files. Gridded data in ERMapper IEEE4Byte Real data files with descriptive header files. NON-DIGITAL – Hard copy – NIL ACCESS CONSTRAINT: Subject to MDBC protocols relating to the release of airborne geophysics data for salinity mapping current at the time of request. LINEAGE: The airborne geophysical survey data were acquired and processed by the airborne geophysical survey contractors Fugro and Kevron. Data acquisition and processing reports compiled by each contractor detail the acquisition and processing parameters. The relevant reports by Owers et. al. (2002) and Kevron Geophysics (2001) are included in the dataset. Processing steps for the electromagnetic data were: 1. High altitude calibration data were used to characterise the system

response in the absence of any ground response. 2. Routines to suppress spheric noise, powerline noise, VLF noise and coil

motion noise were applied to data from survey lines. 3. A three-second wide cosine-tapered stacking filter was then applied to

stack the data. Output from the stacking filter is drawn at 0.2 second intervals.

4. The survey line stacked data are deconvolved using the high altitude reference waveform. The effect of currents in the transmitter loop and airframe (“primary”) are then removed, leaving a “pure” ground response.

5. The deconvolved ground response data are then transformed to B-field response for a perfect 100% duty cycle square wave.

6. The evenly spaced samples are binned into 15 windows as specified in the table below. The output from this step is the “non height pitch roll and geometry corrected window data” (non HPRG data).

Window #

Start sample

End Sample

No of samples

Start time (s)

End time (s)

Centre time (s)

Centre time (ms)

1 1 2 2 0.000007 0.000020 0.000013 0.013 2 3 4 2 0.000033 0.000047 0.000040 0.040 3 5 6 2 0.000060 0.000073 0.000067 0.067 4 7 10 4 0.000087 0.000127 0.000107 0.107 5 11 16 6 0.000140 0.000207 0.000173 0.173 6 17 26 10 0.000220 0.000340 0.000280 0.280 7 27 42 16 0.000353 0.000553 0.000453 0.453


8 43 66 24 0.000567 0.000873 0.000720 0.720 9 67 102 36 0.000887 0.001353 0.001120 1.120 10 103 158 56 0.001367 0.002100 0.001733 1.733 11 159 246 88 0.002113 0.003273 0.002693 2.693 12 247 384 138 0.003287 0.005113 0.004200 4.200 13 385 600 216 0.005127 0.007993 0.006560 6.560 14 601 930 330 0.008007 0.012393 0.010200 10.200 15 931 1500 570 0.012407 0.019993 0.016200 16.200

7. The previous processing steps yield monitor values such as powerline, spherics, VLF and low frequency monitor channels.

8. Also yielded are the “geometric factor” and transmitter to receiver separation values.

9. The output from step is then used to compute “height pitch roll and geometry corrected window data” (HPRG data) via the method of Green (1998). This accounts for variations in the aircraft’s height and attitude as well as the transmitter-receiver geometry. The HPRG data are computed to yield the response that would be expected if all observations had been made with constant aircraft height, attitude and transmitter-receiver geometry.

10. Model-dependent earth conductivity predictions were then computed from the HPRG data output from step Error! Reference source not found.. Two different methods were used. The methods were;

(a) “Conductivity depth imaging” (CDI) via the software package EMFlow (version 4.00). The method is described by Macnae et al (1998). (b) “Layered earth inversion” (LEI) via proprietary Fugro software. Sattel (1998) details this method.

In both of these methods each observation point along a survey line is treated completely separately. They assume the earth to consist of a set of horizontal layers each having a constant electrical conductivity. For each observation point the conductivities and thicknesses of the layers which would generate the observed response are determined. This process is non-unique and model dependent.

11. Further products are then derived from the earth conductivity predictions resulting from step Error! Reference source not found.. These are products are; (a)“Conductivity depth slices” or “Interval Conductivities” which

represent the average of the predicted conductivity over a given depth range below surface.

(b) “Conductive unit parameters” as described in Lane (2000a). This method identifies a conductive unit within the vertical conductivity profile and yields values for its conductivity, thickness, and conductance, depth to its top and bottom and elevation (AHD) of its top and bottom.

12. Gridding Processing steps for the magnetic data were: 1. Manual inspection and editing of profile data to remove any noise spikes

or bursts.


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2. Subtract diurnal variation. 3. Subtract International Geomagnetic Reference Field using the IGRF model

2000 and updated via the secular variation to 2001.5 and add back in the average.

4. Tie line levelling. 5. Microlevelling. 6. Calculation of X and Y gradients from horizontal gradiometer data. 7. Calculation of reduction to the pole. 8. Calculation of first vertical derivative. 9. Gridding. Processing steps for the gamma-ray data were: 1. Apply the spectral smoothing using the Noise Adjusted Singular Value

Decomposition (NASVD) method described by Hovgaard and Grasty (1997).

2. Apply dead-time correction. 3. Apply energy calibration. 4. Remove aircraft and cosmic background. 5. Remove atmospheric radon background. 6. Apply effective altitude correction. 7. Apply Compton scattering (stripping) correction. 8. Apply height attenuation correction. 9. Conversion to equivalent elemental concentrations and dose rate. 10. Tie line levelling. 11. Microlevelling. 12. Gridding. Processing steps for the elevation data were: 1. Apply post-flight differential processing of GPS data. 2. Subtract radar altimeter from GPS ellipsoidal height. 3. Apply correction for GPS antenna and radar altimeter antenna separation. 4. Convert ellipsoidal elevations to Australian Height Datum (geoidal)

elevations via subtraction of AUSGEOID N values. 5. Tie line levelling. 6. Microlevelling. 7. Gridding. POSITIONAL ACCURACY: Positioning was via post-processed differential GPS methods. Horizontal positional accuracy of the data is approximately 1 metre (standard deviation). Vertical accuracy of the derived digital elevation model is approximately 2 metres (standard deviation). ATTRIBUTE ACCURACY: This data has been acquired and processed to a standard of best good practice as of the year 2001. More sophisticated processing algorithms may be applied to these data should they become available. LOGICAL CONSISTENCY:


Not Applicable COMPLETENESS: The MAGSPEC survey digital dataset covers the entire area defined in “Geographic Extent Polygon” at consistent sample spacing. The AEM survey digital dataset (and the entire actual survey) covers the area defined in the “Geographic Extent Polygon for AEM Survey” defined under the “Additional Metadata” heading of this document CONTACT ORGANISATION: Geoscience Australia CONTACT POSITION: Data Distribution Officer

Airborne Geophysics Group CONTACT NAME: Peter Percival Cnr Hindmarsh Drive and Jerrabomberra Ave Symonston

Canberra, 2609 MAIL ADDRESS: GPO Box 378 Canberra ACT 2601 TELEPHONE: (02) 6249 9111 ELECTRONIC MAIL ADDRESS: [email protected] METADATA DATE: 2002/12/11 ADDITIONAL METADATA: GEOGRAPHIC EXTENT POLYGON FOR AEM SURVEY: 147.081 -35.529, 146.768 -35.529, 146.768 -35.647, 146.721 -35.647, 146.721 -35.600, 146.636 -35.594, 146.618 -35.756, 147.046 -35.807, 147.047 -35.736, 147.081 -35.736. AEM SYSTEM SPECIFICATION Base frequency 25Hz Transmitter area 244m2 Transmitter turns 1 Waveform Square Duty cycle 50% Transmitter pulse width 10 ms Transmitter off-time 10 ms Peak current 300 A Peak moment 73,200 Am2 Average moment 36,600 Am2 Sample rate 75 kHz Sample interval 13.33 microseconds


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Samples per half-cycle 1500 System bandwidth 25 Hz to 37.5 kHz Flying height 120m (nominal) EM receiver Towed bird with 3 component

dB/dt coils (X and Z components are recorded and processed)

Tx-Rx horizontal separation 120m (nominal) Tx-Rx vertical separation 30m (nominal) Stacked data output interval 200 ms (~12 m) Number of output windows 15 Window centre times 13 s to 16.2 ms Magnetometer Stinger-mounted caesium vapour Magnetometer compensation Fully digital Magnetometer output interval 200 ms (~12 m) Magnetometer resolution 0.001nT Typical noise level 0.2nT GPS cycle rate 1 second MAGSPEC SYSTEM SPECIFICATION Aircraft Magnetometer Geometrics G-822A Caesium vapour Magnetic Compensator RMS Instruments Automatic Aeromagnetic

Digital Compensator (AADC) Base station magnetometer Geometrics G856 proton precession Gamma-ray spectrometer Exploranium GR820, 256 channels Gamma-ray detector NaI(T1) crystals; 50 L down Altimeter Sperry AA-210 radio altimeter Barometer Rosemount 1241m Thermometer Rosemount Model 2200 temperature sensor Navigation system Fugro Omnistar Virtual Base Station mode

with 12 Ashtech GPS receiver. Flight Track Recording VHS video tracking camera with wide-angle

lens Data acquisition system RMS Instruments DAS-8 digital acquisition

system SCALE/RESOLUTION The fundamental resolution of airborne geophysical measurements is most usually quoted as the “footprint” of the system. The footprint is defined as the area upon the earth from which 90% of the measured response originates. The size of the footprint is a function of the measurement and processing system characteristics and the physics of the quantities being measured. For these surveys, it is estimated that the footprints of the various measurement and processing systems and physical quantities are as follows; Electromagnetic ~200 metre radius Magnetic NA (depends on anomaly source depth) Gamma-ray ~360 metre radius Elevation ~10 metre radius


The data resolution of airborne geophysical data is a function of the sampling density along survey lines and the spacing between survey lines (detailed in the abstract). Various fields (attributes) of the point located line data included in this dataset have been “gridded” to generate gridded data files. This involves interpolation of the semi-irregularly sampled data onto a regularly spaced positions on a grid lattice (Briggs, 1974). The size of the grid cells is one fifth of the flight line spacing. Hence the AEM survey has a grid cell size of 40 metres and the MAGSPEC survey has a grid cell size of 20 metres. As the data are not hardcopy (or digital map layouts/plot files) but fundamental digital data, the scale of the data is dependent on the preferences of the end user of the data. However, the scale of hardcopy presentation of airborne geophysical data is usually determined by the flight line spacing at which the data acquisition was undertaken. Typically, it is recommended that the AEM survey (200-metre line spacing) be presented at 1:50,000 scale while the MAGSPEC survey (100-metre line spacing) be presented at 1:25,000 scale. RESTRICTION ON USE: Subject to MDBC protocols relating to the release of airborne geophysics data for salinity mapping current at the time of request. PROJECTION AND DATUM: Note that gridded data are stored in a projected coordinate system only. Point located data are attributed with both geodetic and projected coordinates. Projection Name: Map Grid of Australia, Zone 55 Units: Metres Datum: Geocentric Datum of Australia 1994 (GDA94) Epoch: 1994.0 Ellipsoid: GRS80 Semi-major axis (a): 6,378,137.0 metres Inverse flattening (1/f): 298.257222101 Central meridian 147°00’00’’ False Easting: 500,000 metres False Northing: 10,000,000 metres

Data Dictionary: The data exist in three forms as follows; 1. Point located or line data are stored in ASCII (.asc or .dat) files formatted

via space delimited columns. Each record of the file represents one sample along a flight line. A comprehensive header file (.hdr) is associated with each file that describes the data stored within and the numeric format of each column in the file.


45

2. Gridded data are stored in binary files as ERMapper single band IEEE4Byte Real data types. A comprehensive header (.ers) file is associated with each grid file which describes the data stored within and geographic positioning of the grid.

3. Data Acquisition and Processing reports are stored as Microsoft Word (.doc) files.

The data are stored on fourteen CD-ROMS. The contents of each is detailed in the table following. CD-ROM TITLE Contents Label Contents Billabong Creek Airborne Electromagnetic Survey

Final Non-Height, Pitch, Roll and Geometry Corrected Line Data

X and Z component line data for Non HPRG electromagnetic data. Does not include repeat calibration lines.

Billabong Creek Airborne Electromagnetic Survey

Final Height, Pitch, Roll and Geometry Corrected Line Data

X and Z component line data for Non HPRG electromagnetic data. Does not include repeat calibration lines.


Raw and Final Calibration Line Electromagnetic, Magnetic and Elevation Data.

Repeat calibration line data. Includes X and Z component Non HPRG and HPRG electromagnetics, CDI, magnetics, elevation data. Includes raw and final data.


Final Magnetic Line Data Processed magnetic line data including survey and repeat calibration lines


Final Elevation Line Data Processed elevation line data including survey and repeat calibration lines


Final Electromagnetic CDI and Derived Unit Parameter Line Data

Processed line data for the predicted earth conductivities and their derived unit parameters computed by the conductivity depth-imaging (CDI) algorithm.


Final Electromagnetic Layer Earth Inversion and Derived Unit Parameter Line Data

Processed line data for the predicted earth conductivities computed by the layered earth inversion (LEI) algorithm. Includes Microsoft Word document describing the algorithm.


Final Gridded Electromagnetic, Magnetic and Elevation Data

Gridded data derived from the processed line data. Includes magnetic grids, elevation grids, CDI depth slice grids and CDI unit parameter grids.


Data Acquisition and Processing Report

Report compiled by Fugro Airborne Surveys, which details the data acquisition and processing for the AEM survey.

Billabong Creek Airborne Magnetic, Gamma-ray and Elevation Survey.

Final Magnetic Gridded and Line Data

Processed magnetic line data and their derived gridded data. Produced from the MAGSPEC survey.

Billabong Creek Final Horizontal Magnetic Processed horizontal gradiometer


CD-ROM TITLE Contents Label Contents Airborne Magnetic, Gamma-ray and Elevation Survey.

Gradiometer Gridded Data magnetic line data and their derived gridded data. Produced from the MAGSPEC survey.


Final Elevation Gridded and Line Data.

Processed elevation line data and their derived gridded data. Produced from the MAGSPEC survey.


Final Gamma-ray Gridded and Line Data.

Processed gamma-ray line data and their derived gridded data. Produced from the MAGSPEC survey.

Honeysuckle Ck & Billabong Ck Airborne Magnetic, Gamma-ray and Elevation Survey.

Final Acquisition and Processing Report

Report compiled by Kevron Geophysics, which details the data acquisition and processing for the MAGSPEC survey.


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References: Briggs, I.C., 1974. Machine Contouring Using Minimum Curvature. Geophysics, v.39: p. 39 - 48. Green, A., 1998. Altitude correction of time domain AEM data for image display and geological mapping, using the Apparent Dipole Depth (ADD) method. Expl. Geoph. 29, 87-91. Grasty, R.L, and Minty, B.R.S, 1995: A Guide To The Technical Specifications For a Airborne Gamma-Ray Survey. AGSO Record 1995/60. Horsfall, K.R., (1997). Airborne magnetic and gamma-ray data acquisition. AGSO Journal of Geology and Geophysics, 17, 23-30. Hovgaard, J. and Grasty, R.L, (1997). Reducing noise in airborne gamma-ray data through spectral component analysis. Exploration 97, Ontario Geological Survey. Kevron Geophysics, 2001, Operations and processing report, Billabong Creek and Billabong Creek geophysical surveys. Kevron Geophysics report to the Bureau of Rural Sciences, 2001. Unpublished. Lane, R., 2000, Conductive unit parameters : summarising complex conductivity distributions: Paper accepted for presentation at the SEG Annual Meeting, August 2000. Lane, R., Green, A., Golding, C., Owers, M., Pik, P., Plunkett, C., Sattel, D., and Thorn, B., 2000, An example of 3D conductivity mapping using the TEMPEST airborne electromagnetic system:Exploration Geophysics, 31, 162-172. Owers, M., Sattel, D. and Stenning, L., 2002, Billabong Creek, New South Wales, acquisition and processing report. Fugro Airborne Surveys report to the Bureau of Rural Sciences, 2002. Unpublished. Macnae, J.C., King, A., Stolz, N., Osmakoff, A. and Blaha, A., 1998, Fast AEM data processing and inversion: Exploration Geophysics, 29, 163-169. Sattel, D., 1998, Conductivity information in three dimensions: Exploration Geophysics 29, 157-162. Terms and Conditions: Subject to MDBC protocols relating to the release of Murray-Darling Basin Mapping data sets current at the time of request.


Definition Murray-Darling Basin Mapping includes all Murray-Darling Basin Commission (MDBC) copyrighted mapping and survey information, in both digital and hardcopy formats, of the Murray-Darling Basin. Specifically, Murray-Darling Basin Mapping includes: - Landsat TM and AVHRR imagery - Vegetation mapping - Soils and lithology mapping - Wetlands GIS - Hydrogeology - Disposal basins - Socio-economic data - Climate data - Irrigation area information This information is copyright to the MDBC. Terms and Conditions The MDBC provides access to this data to cooperating users for non-commercial purposes providing they meet any formatting and transfer costs associated with the data. The terms of the copyright are: The sale, transfer or reproduction of Murray-Darling Basin Mapping or

derived products, in non-approved formats or for commercial purposes, whether by map or digital data is prohibited without a licence in writing from the MDBC.

All Murray-Darling Basin Mapping digital files and derived products will be deleted from computing and data storage systems upon completion of the approved use, unless written agreement is reached on royalties payable for retaining this data.

All mapping and publications using Murray-Darling Basin Mapping will acknowledge MDBC copyright.

The user accepts that Murray-Darling Basin Commission is not liable for any loss or damage incurred through the use of Murray-Darling Basin Mapping products.

Failure to comply with the above terms and conditions is a breach of copyright.


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Appendix 2: Billabong Creek: Drilling locations, downhole logs and laboratory data

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Documents

MDBC Airborne Geophysics Project: Final Reportdata.daff.gov.au/.../BBC_ABARES_MDBC_final.pdfMDBC Airborne Geophysics Project: Data Acquisition and Interpretation –Final Report 5