Embed Size (px)
Citation preview
Middle Pleistocene glacial outwash in poljes of the Dinaric karst
K. R. Adamson1, J. C. Woodward2, P. D. Hughes2
1 Geography and Environmental Management, School of Science and the Environment, Manchester Metropolitan University, Manchester, M1 5GD, UK2 Quaternary Environments and Geoarchaeology Research Group, Geography, School ofEnvironment, Education and Development, The University of Manchester, Manchester, M13 9PL, UK
ABSTRACT
Poljes are distinctive features of Mediterranean karst landscapes but their Pleistocene sedimentary fills have not been widely investigated. Most previous research has focused on their formation and hydrology. Many Mediterranean poljes are situated downstream of high mountains that were glaciated during the cold stages of the Pleistocene so that meltwater streams delivered glacially-derived sediment into these basins. This study examines the Pleistocene alluvial records in karst poljes surrounding Mount Orjen in western Montenegro and explores their wider significance. There is a record of at least four glaciations preserved on Mount Orjen - two from the Middle Pleistocene (MIS 12 & 6) and two from the last cold stage (MIS 5d-2), including the Younger Dryas. Detailed sedimentological analysis and Uranium-series dating indicate that the Orjen poljes were filled with thick deposits of coarse and fine-grained alluvium prior to 350 ka, during the major glacial phase of MIS 12. During the cold stages that followed MIS 12, ice was less extensive and limited to the Orjen plateau – there is little evidence of outwash deposition during these later glaciations. Surface runoff and sediment supply were greatly reduced after MIS 12 and largely channelled into the subterranean karst network. The poljes around Orjen contain some of the best-preserved records of Middle Pleistocene glacial outwash in the Mediterranean. These thick deposits of permeable coarse-grained alluvium are an important element of regional hydrogeology. This paper highlights the dominant control of the glaciokarst system on the formation and preservation of the region’s polje sedimentary records. The thick outwash deposits in the poljes of Montenegro represent an important legacy of an extensive Middle Pleistocene glaciation whose wider impacts have not been fully appreciated. Indeed, we argue that many of the poljes in the classic karst landscapes of the wider Dinaric Alps were also filled with glacial outwash during the Middle Pleistocene.
INTRODUCTION
Poljes (derived from the Serbo-Croat term meaning ‘field’) are enclosed, flat-bottomed depressions
bounded by steep slopes. They are widespread in limestone karst and can extend over several
hundred square kilometres (Gams, 1978; Ford and Williams, 1989; 2007; Bognar et al., 2012). Due
to the widespread occurrence of carbonate lithologies, and the extreme base level falls (>1500 m) of
the Late Miocene Messinian Salinity Crisis (Audra et al., 2004; Mocochain et al., 2006; Bakalowicz et
al., 2008), the Mediterranean contains some of the world’s deepest and well-developed karst
networks (Lewin and Woodward, 2009). The Balkan Peninsula contains extensive subterranean
1
123456789
1011121314151617181920212223242526272829303132333435363738
39
40
41
42
43
44
drainage networks and surface karst features, including poljes and dolines. Many of these poljes are
located within or adjacent to high mountains. It is now well established that large ice caps and
glaciers developed across much of the high Mediterranean mountain karst during the cold stages of
the Pleistocene (Cvijić, 1900; Messerli, 1967; Woodward et al., 2004; Hughes et al., 2006a, Hughes
and Woodward, 2009). Several aspects relating to the role of glaciers in the development of karst
terrain in Montenegro and the wider Dinaric region were discussed in classic papers by Liedtke
(1962) and Nicod (1968). Some of the largest ice masses developed at high elevations in the Dinaric
Alps, including parts of Slovenia (Bavec et al., 2004), Croatia (Bognar et al., 1991 1992; Marjanac and
Marjanac 2004; Bognar and Faivre 2006; Bočić et al., 2012), Montenegro (Cvijić, 1900; 1917; Liedtke,
1962; Nicod, 1968; Hughes et al., 2010; 2011; Stepišnik and Žebre, 2011; Žebre and Stepišnik, 2014),
and Albania (Cvijić, 1913; 1914; Milivojević et al., 2008) as well as further to the south in the
mountains of Greece (Woodward et al., 2004; Hughes et al., 2006b). These glaciers contributed large
volumes of meltwater and sediment to surrounding basins (Nicod 1968; Gams, 1978; Woodward et
al., 2008; Adamson et al., 2014a).
Some of the earliest work on the Dinaric karst was published by Jovan Cvijić in 1893 (for a review of
this early work see Sanders, 1921). Since then, the poljes in this region have become some of the
most intensively studied in the world with regards to their formation and hydrological characteristics
(Liedtke, 1962; Riđanović, 1966; Nicod, 1968, 2003; Malez et al., 1975; Bonacci, 1987; Bognar et al.,
2012; Bonacci et al., 2013). The late Ivan Gams was one of the first to highlight the potential role of
large poljes in preserving the downstream sedimentary record of headwater glaciation and related
fluvial activity. Gams (1973) referred to these as piedmont poljes. Polje formation has been
discussed in detail (Jennings, 1985; Gams 1978; Ford and Williams, 1989; 2007; Nicod, 2003), but
there has been little systematic study of the Pleistocene sedimentary fills in the poljes of the Dinaric
karst and most of these records are not well dated. Against this background, this study focuses on
the Pleistocene deposits within the poljes surrounding the Orjen massif in western Montenegro (Fig.
1 and 2). It has four key aims:
To document the stratigraphy and sedimentology of the Pleistocene deposits in karst poljes.
To establish the source of these sediments
To establish the timing of polje infilling using uranium-series dating.
To consider the implications of the polje fills around Mount Orjen for the wider Dinaric
region.
2
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
BACKGROUND: POLJES OF THE DINARIC KARST
Geological setting
The dominance of limestone lithologies, often of considerable thickness and purity, in a humid
climate setting means that large areas of the Dinaric Alps have been exposed to intense
karstification during the Quaternary and earlier periods. This is the classic region for the study of
karst geomorphology – distinctive landforms including poljes, sinkholes, sinking streams, enclosed
depressions, and fluted rock outcrops are widespread. Caves and subterranean drainage networks
are also well-developed. Areas of high rainfall, such as Montenegro, have particularly active karst
systems (Lewin and Woodward, 2009; Telbisz, 2010a; 2010b). Gams (1969) pointed out that high
concentrations of poljes frequently coincide with areas of highest annual precipitation, including
Inner Carniola (Notranjsko), East Bosnia-Hercegovina, and western Montenegro. Djurović and
Petrović (2007) have suggested that karst processes have also aided the formation of over 20 large
canyons across Montenegro – many of which drain glaciated mountain terrains. The Eastern Adriatic
coast comprises a Mesozoic-Early Palaeogene carbonate platform (c. 8000 m thick), which has been
extensively karstified during tectonic folding, faulting, and uplift (Surić et al., 2005; 2009). Sea level
rise during the Late Pleistocene and Holocene has flooded this carbonate platform, submerging
many karstic forms (Surić et al., 2009).
Polje formation and classification
In the Dinaric karst, poljes vary in size from c. 1 to 474 km2 and demonstrate a range of formation
mechanisms and hydrogeological characteristics (see Jennings, 1985; Gams 1978; Ford and Williams,
1989; Nicod, 2003). Three criteria are considered common to most poljes (Gams, 1978; Ford and
Williams, 1989; 2007). They are:
Flat bottomed and floored by bedrock or unconsolidated sediment.
Closed basins constrained on at least one side by steeply rising slopes.
Associated with a karst drainage system.
In the 1970s, based on observations in the region of Postojna Cave, Slovenia, Gams (1973; 1978)
proposed a five-fold classification of polje formation (Table 1) that has been distilled into three basic
morphogenic types by Ford and Williams (1989):
3
79808182
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
9899
100
101
102
103
104
105
106
107
108
109
110
111
112
113
Border poljes: These are dominated by allogenic sediment inputs and develop where, during
fluvial activity, lateral planation and alluviation dominate over incision.
Structural poljes: These are geologically controlled and are associated with grabens and
fault-angle depressions. This type of polje is an important feature of the Dinaric karst
landscape where polje morphology is conditioned by geological characteristics.
Base level: These poljes are controlled by water table fluctuations and occur where the
epiphreatic zone intersects the surface.
Hydrological characteristics have also been used as a basis for polje classification. Bonacci (1987)
identified four types of polje in the Bosnian Dinarides, based on their drainage pathways: 1) closed
poljes, which are the most dominant in the Bosnia-Herzegovina region; 2) upstream open poljes; 3)
downstream open poljes; 4) upstream and downstream open poljes. Types 1 and 2 have only
subterranean drainage systems. Types 3 and 4 have both surface and subterranean drainage
networks. The geological and topographic configuration of poljes leaves many of them prone to
seasonal flooding (Gams, 1978; López-Chicano et al., 2002; Bonacci et al., 2013), and these wetland
areas were favoured locations for Palaeolithic humans (van Andel and Runnels, 2005). These basins
may contain valuable sedimentary records of regional Quaternary landscape dynamics and
Palaeolithic archaeology.
Quaternary glacial history
Much of the Mediterranean mountain karst above c. 1500 m has been shaped by Pleistocene
glaciation, leading to the production of widespread ‘glaciokarst’ terrain (Liedtke, 1962; Nicod, 1968;
Smart, 1986; Bogdan and Leszek, 1999; Lewin and Woodward, 2009; Woodward and Hughes, 2011).
This forms the dominant landscape in many upland parts of the Balkans (including the Dinaric Alps in
Montenegro and the Pindus Mountains of Greece) and elsewhere in the Mediterranean, including
the Cantabrian Mountains in Spain (Serrano et al., 2013; Hughes and Woodward, 2009). The first
radiometric ages (Uranium-series) from the glacial karst of the Balkans were published from the till
deposits on Mount Tymphi in northwest Greece (Woodward et al., 2004). Detailed mapping and the
development of robust geochronologies has, over the last decade, transformed our understanding of
the regional glacial record. There is now evidence, from the Pindus Mountains of Greece, the upland
massifs of Montenegro, and the Julian Alps of Slovenia for example, of glaciation during Marine
Isotope Stages (MIS) 12 (478-424 ka), 8 (300-243 ka), 6 (191-123 ka), 5d-2 (109-11.7 ka) and the
Younger Dryas (12.9 - 11.7 ka) (Woodward et al., 2004; Bavec et al., 2004; Hughes et al., 2006, 2010,
4
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
2011; Woodward et al., 2008). A few small glaciers still survive today in the highest karst peaks of
Slovenia (Gabrovec, 1998), Montenegro (Hughes, 2007, 2008; Djurović, 2013) and Albania
(Milivojević et al., 2008; Hughes, 2009). Evidence of Pleistocene glaciation has also been identified in
the gypsum karst of the Pyrenees (Lewis et al., 2009); the limestone karst of central Italy (Giraudi et
al., 2010); the carbonate terrain of southwest Turkey (Zahno et al., 2010) as well as in the limestones
of the High Atlas (such as around Irhil M’Goun) in Morocco and even in the relatively low-lying peaks
of the Djurdjura in the Kabylie region of Algeria (Hughes et al., 2004). In some locations, ice
extended down from the high mountains to below 500 m a.s.l., and into lowland poljes and valleys.
Gams (1969) argued that, during the Neogene and Quaternary, large areas of the Dinaric karst would
have been covered by allogenic clastic sediments (including alluvium, colluvium, and aeolian
sediments), and much of this would have been preserved within karst depressions such as poljes. It
was suggested that many poljes located downstream of the glaciated mountains would have been
filled with alluvial sands and gravels (glacial outwash) during the Pleistocene. In fact, even in 1969,
Gams speculated that glacial-fluvial processes may have played an important role in the infilling of
these basins, but the absence of radiometric dates did not allow him to establish the timing of
sediment deposition. Poljes can accommodate very thick Quaternary fills. The recent application of
seismic surveys and electrical tomography in the karst poljes of Crete, for example, has shown that
the Quaternary sedimentary fill can reach thicknesses of 40 to 130 m (Hamdan et al., 2010, 2012).
The development and wider application of U-series, radiocarbon, and luminescence dating
techniques, and an improved understanding of the sedimentary products of glaciation on limestone
terrains, mean that polje records can now be securely dated and the classic hypotheses on polje
infilling can be tested.
Mount Orjen: karst landscape and Quaternary glacial history
Orjen (1894 m) is a large upland limestone karst massif (>1000 m a.s.l.) with dolines, sinkholes (e.g.
Lisac and Duboki Do), and poljes (e.g. Pirina Poljana, Grahovo, and Dvrsno). The plateau is bounded
by steep slopes and a radial network of gorges, many of which drain into the surrounding poljes (Fig.
2). An extensive network of caverns and subterranean passages has also been reported (Tisserant,
1974; Groupe Spéléologique Muséum National d’Histoire Naturelle, Paris, 2003; Stepišnik et al.,
2009). All of these features are characteristic of the classic karst landscapes across Montenegro
(Stepišnik and Žebre, 2011; Žebre and Stepišnik, 2014) and other parts of the Dinaric Alps (Gams,
1969, 1978, 2005; Lewin and Woodward, 2009; Telbisz, 2010a, 2010b; Bočić et al., 2012).
5
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
Montenegro is one of the wettest parts of Europe. In some locations, such as Crkvice on the eastern
margins of the Orjen massif, annual average recorded precipitation may exceed 4500 mm (Magaš,
2002; Ducić et al., 2012) Precipitation totals are likely to be significantly greater in the highest
mountains where large ice caps developed during the Middle and Late Pleistocene. There is well-
preserved evidence, in the form of moraines and related glacial features, of at least four glacial
phases on Mount Orjen (Hughes et al., 2010). These have been correlated, on the basis of
morphostratigraphy and U-series dates from secondary carbonates, to MIS 12, and 6, and to two
periods of glacier development during MIS 5d-2, including the Younger Dryas (Fig. 2). The largest ice
cap, which developed during MIS 12, covered an area of 136 km2 on the Orjen plateau above 1000 m
a.s.l. and reached a maximum thickness of 450 m. Outlet glaciers from this ice cap extended below
1000 m into the surrounding valleys and poljes. In places the glaciers reached down to c. 500 m
above modern sea level. This is consistent with the glacial evidence from the massifs of central
Montenegro (Hughes et al., 2006, 2011) and the Pindus Mountains of Northwest Greece (Hughes et
al., 2006; Woodward et al., 2008; Woodward and Hughes, 2011) which also indicate a major glacial
phase during MIS 12. On Mount Orjen, during the cold stages that followed MIS 12, ice masses were
constrained to the plateau above 1000 m (MIS 6) and highest peaks (MIS 5d-2 and Younger Dryas).
FIELD AND LABORATORY METHODS
The sedimentary records within seven of the poljes around Mount Orjen have been investigated in
detail. The largest poljes lie beyond the margins of the plateau, and outside the MIS 12 ice margins,
at elevations below 1000 m a.s.l. Two small poljes are situated at the edge of the high altitude massif
and downstream of the MIS 6 ice limits (Fig. 2).
Geomorphological mapping and sedimentology
Poljes were mapped using aerial photographs, satellite imagery, and field observations. Gravel
quarries are present in most poljes and these provided excellent exposures throughout the study
area. A total of 25 sedimentary exposures were logged in detail using standard sedimentological
techniques noting changes in sedimentary structures, grain size, colour, and clast fabric (see
Adamson et al., 2014a, 2014b).
Geochronology
Soil profile development index
6
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200201202
203
204
205
206207208
209
210
211
212
213
214
215
216
217
Soil profiles (20-50 cm thick) have developed at the surface of all poljes. The Harden Index of soil
profile development (Harden, 1989; Birkeland, 1999) was used for relative dating to correlate land
surfaces. This method, which has been used elsewhere in the Dinaric karst region (Hughes et al.,
2006; 2010), uses nine parameters (including soil pH; colour; the characteristics of soil structure; and
clay films) to develop a soil profile development score.
Uranium-series ages
Ten samples of secondary carbonates that had formed within the coarse-grained fluvial sediment
matrix in polje fills were U-series dated (for sample preparation and analysis procedure see
Adamson et al., 2014a). These provide minimum ages for the timing of alluviation, and are used, in
association with other data, to correlate the polje records with other Quaternary deposits
surrounding Orjen (Adamson et al., 2014a), including the glacial record upstream. The glacial record
has also been dated using U-series methods (n=12) (Hughes et al., 2010).
RESULTS
Polje morphology and sedimentology
The seven poljes around Mount Orjen vary in size from 0.5 to 20.5 km2 (Table 2), and observed
sedimentary exposures in these poljes can exceed 10 m in height (Fig. 3-5). It is likely that the depth
of many of the polje fills is considerably greater than this (Gams, 2005; Hamdan et al., 2010, 2012),
but the maximum extent has not yet been observed in any of the studied poljes. Kruševice (0.6 km 2)
and Unijerina (0.5 km2) are considerably smaller than the other poljes at Orjen, but their
morphological characteristics and deep exposures are entirely consistent with the standard polje
classification (Nicod, 2003; Fig. 5).
Poljes beyond the maximum MIS 12 ice margins
In the poljes situated beyond the former ice limits, thick sequences of coarse grained, flat bedded,
limestone gravels and sands dominate the sedimentary fills. Sand lenses and fine sediment (silt and
clay) interstratifications are also common.
7
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234235
236
237238
239
240
241
242
243
244
245
246
247
248
249
250
251
At Dvrsno, northeast Orjen (Fig. 2), ice extended into the polje during MIS 12 and a large moraine is
now preserved at its northeastern margins (Hughes et al., 2010). Several exposures along a transect
extending from the moraine to the centre of the polje have been analysed (Fig. 3). The polje is filled
with massive, coarse-grained alluvium, which becomes increasingly stratified, and often cross-
bedded, with distance from the ice margin. Clast density decreases from 60 to 30% towards the
centre of the basin, as the fine sediment matrix becomes increasingly dominant. At the southern end
of the polje, furthest from the ice margin, a key feature of the sediments is the predominance of
well-stratified cross-bedded sands and silts. A 50 cm-thick soil horizon has developed at the polje
surface; it yielded PDI values of 11.80 close to the former ice margins, and 7.35 towards the centre
of the polje (Table 2). Secondary carbonates were not observed in Dvrsno polje. Determining the age
of these deposits relies on correlation with other polje records through the Harden Index and
sedimentological characteristics.
At Grahovo, the polje sediments closely resemble those observed at Dvrsno and present massive,
stratified sands and gravels (Fig. 4). Again, a soil has developed at the polje surface (PDI 9.91) and
the here the sediments are weakly cemented with secondary carbonate accumulations. U-series
analysis of a secondary carbonate sample close to the sediment surface provided an infinite age of
>350 ka (Section G1; Table 2).
Pirina Poljana is the most extensive polje in the vicinity of Mount Orjen (20.5 km 2) and is located
downstream of one of the largest outlet glaciers that drained the Orjen ice cap during MIS 12.
Sediments on the ice proximal side of the polje comprise poorly stratified coarse-grained sands and
gravels with interbedded fine sand and silt horizons (soil PDI 9.12). The sequence is weakly
cemented throughout and two secondary carbonate samples have been dated to 213.5 ± 11.3 ka
and 77.2 ± 2.0 ka (Fig. 4).
The poljes in southwest Orjen are much smaller than those in the north (Table 2), and are separated
by a series of bedrock ridges. Unlike the other poljes, Vrbanje (2.8 km2) lies both beyond the MIS 12
limits and on the high altitude plateau. During MIS 12, three outlet glaciers drained into the polje
and a series of moraines are now well-preserved on its margins. Exposures at the ice distal side of
the polje show well-stratified, matrix-supported alluvium (clast density 20-60%). A 30 cm-thick soil
profile yielded a PDI of 4.88 and a well-cemented secondary carbonate sample from close to the
surface has been U-series dated to 126.6 ± 4.5 ka (Fig. 4).
8
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
Kruševice is one of the smallest poljes at Orjen (0.6 km2). During the Pleistocene, the ice cap was
restricted to the high altitude plateau and meltwater and sediment would have drained into the
polje via bedrock gorges. As in the other polje sequences, its sediments are dominated by limestone-
derived, coarse-grained alluvium with frequent sand and gravel lenses. Fine sediments become
increasingly abundant, and clasts more rounded, with distance from the ice margin (Fig. 4).
Secondary carbonate development has not been observed here, but the sequence is capped by a 60
cm-thick soil profile with a PDI value of 13.75 and this is consistent with the values obtained from
Dvrsno and Pirina Poljana.
Poljes within the maximum MIS 12 ice margins
In comparison to the large depocentres beyond the massif, the preservation of coarse-grained fluvial
sediments at higher altitudes is limited. The thickest exposures (up to 10 m) are within two small
poljes at Crkvice and Unijerina on the eastern side of the plateau (Figs. 2 and 5). These are situated
downstream of a suite of MIS 6 moraines (Hughes et al., 2010; Adamson et al., 2014a) and the
sedimentary sequences are more complex than those seen beyond the plateau. Three exposures at
Unijerina present a stacked sequence of three facies: well-stratified alluvial sands and gravels; a
massive diamicton (soil PDI: 6.29); and a second facies of well-stratified alluvium (soil PDI: 1.43) (Fig.
5). Fine silt and clay horizons are abundant here and attain thicknesses of up to 30 cm; these are a
product of relatively low energy cold stage fluvial systems that periodically flooded these poljes.
Crkvice contains a similar sequence, with a unit of stratified alluvium (soil PDI: 4.12) adjacent to a
thick unit of massive diamicton (soil PDI: 3.92). The soil development indices are considerably lower
than those within the poljes beyond the ice margins, and suggest a much later phase of landscape
stabilisation as the ice retreated to its MIS 6 position. This is supported by the U-series ages from
secondary carbonate rinds at both Unijerina (16.6 ± 0.4 ka to >350 ka) and Crkvice (144.2 ± 5.1 ka
and 18.5 ± 0.4 ka) (Table 2; Fig. 5), which also suggest a more complex depositional history on the
plateau.
DISCUSSION
The nature and timing of sediment deposition
Previous research in the glaciokarst of Montenegro (see Liedtke, 1962; Nicod, 1968) has highlighted
the potential significance of glacial meltwater streams in the transfer of coarse- and fine-grained
9
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313314315316
317
318
319
320
sediment, and the infilling of karst depressions, but without systematic investigation of the deposits
or the development of any geochronological framework. All of the large lowland poljes beyond the
Orjen plateau contain thick sequences of coarse-grained, limestone-rich, glacial outwash with
exposures >10 m deep. These sediments are identical to the limestone-dominated Pleistocene
glaciofluvial deposits described by Lewin et al. (1991) and Woodward et al. (1992; 1995) in the
Voidomatis Basin of northwest Greece. A key feature of the polje outwash sediments is the presence
of a very significant component of limestone-derived silts. This material can only be produced by
grinding and abrasion in a glacial environment (Woodward et al. 1992; Adamson et al. 2014b). The
polje outwash sediments generally become finer and increasingly matrix-dominated with distance
from the Pleistocene ice margins. This results from the progressive infilling of the poljes and is
consistent with alluvial fan-type sedimentology involving multiple gravel bed channels with high
sediment loads. Importantly, buried soil horizons and/or major sediment unconformities have not
been observed within the outwash deposits filling the poljes surrounding the plateau. Since deposits
of this composition have been observed to become strongly weathered under interglacial climates
(Woodward et al., 1994), this suggests that the bulk of the sediments were deposited during a single
cold stage and perhaps quite rapidly. Based on the U-series ages (Table 2), this infilling occurred
prior to 350 ka. This is consistent with the morphological and stratigraphic evidence and U-series
ages from the glacial record of Orjen (Hughes et al., 2010), and elsewhere in the Dinaric and Balkan
region, including Greece (Hughes et al., 2006; 2011), where all the records indicate that the largest
glacial phase occurred before 350 ka, and is correlated to MIS 12 (Skamnellian Stage of Greece;
Hughes et al., 2006). This was a phase of major landscape transformation. At Orjen, ice advanced
beyond the plateau and into the poljes depositing large volumes of glacially-derived sediment. As
glacial outwash was deposited across these basins, they would have formed a major source of
aeolian fine-grained silt (Wright, 2001; Marković et al., 2009; Zöller et al., 2009; Stevens et al., 2011;
Adamson et al., 2014b). This carbonate-rich fine material was susceptible to aeolian entrainment
and long distance transport (Wright, 2001; Giraudi, 2010). It may have been an important
contributor to the loess deposits within the major basins of Eastern Europe including those in Serbia
and the wider Pannonian basin, for example (Adamson et al. 2014b). The presence of great
thicknesses of highly permeable, coarse-grained outwash deposits in all of these poljes (Figs 3 and 4)
also constitutes a key feature of local and regional hydrogeology. This is another legacy of the
region’s glacial past.
All of the secondary carbonate samples were taken from near-surface horizons, often at the base of
thick soil profiles (up to 60 cm). This indicates that many polje surfaces became stabilised following
10
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
the initial infilling, and have since received very limited clastic sediment input. Vrbanje, west Orjen,
is an exception to this, and some of the U-series ages may indicate a phase of later outwash
deposition during MIS 6. Based on the evidence from other poljes around Orjen, and elsewhere
such as in Crete (Hamdan et al., 2010; 2012), it is also likely that these sediments are underlain by
deposits from MIS 12, but these older outwash sediments are not exposed. At Pirina Poljana and
Unijerina, younger U-series ages have been obtained from samples that are stratigraphically above
or adjacent to calcites with much older ages. These represent later phases of secondary carbonate
formation within pre-existing polje sediments (see Adamson et al., 2014a) as has been shown in a
range of depositonal contexts elsewhere (Woodward et al. 2004; Hughes et al. 2006).
Within the maximum Pleistocene ice margins, a more complex stratigraphy has been preserved
within the poljes. At Unijerina, on the eastern edge of the Orjen plateau, a facies of well-stratified
alluvial sands and gravels is overlain by a massive diamict, and the sequence is capped by well-
cemented alluvial facies. This is consistent with the sequence at Crkvice polje, and records changes
in the ice margin on the plateau when glacier ice was found only at higher elevations in the cold
stages after MIS 12 (Table 2). Thick units of fine silt and clay (up to 30 cm thick), which also contain
evidence of dropstones, are present at Unijerina. These are indicative of a small-scale shallow
lacustrine environment on the plateau perhaps on a glacial foreland. In all locations, the outwash
sediments are dominated by limestone-derived material.
Glaciokarst controls on sediment preservation: the role of poljes as a sedimentary archive
There is only very limited evidence of coarse-grained fluvial deposition in the poljes around Mount
Orjen after MIS 12, despite the evidence for glaciation on the plateau during MIS 6 and 5d-2
(Hughes et al., 2010). The absence of well defined river channels at the present surface of the
poljes, or well-defined palaeochannels within the sedimentary record, indicates that there has been
limited large-scale fluvial activity in the poljes since the major depositional phase of MIS 12. This
suggests that the surrounding karst has exerted a dominant influence on runoff hydrology and
sediment transfer since MIS 12. Present-day runoff around Orjen is dominated by subterranean flow
and this is facilitated by the extensive subterranean karst networks that were formed during the Late
Miocene (Mocochain et al., 2006). It is likely that this was also the case during earlier interglacials
and glacials. During the cold stages that followed MIS 12, the ice was constrained to the plateau
above 1000 m, exposing a greater area of the limestone karst massif beyond the ice margins. The
evidence from the poljes around Mount Orjen suggests that outwash sediments were no longer
11
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
delivered directly into the poljes, and were instead preferentially routed through the subterranean
channel networks (Fig. 6). It is also important to appreciate that the cold stages after MIS 12 were
associated with smaller ice masses and therefore much reduced meltwater and outwash sediment
fluxes (Adamson et al 2014a). The transfer of Pleistocene glaciofluvial sediments through
subterranean passages has been reported in many parts of the world including karst environments
in Colorado (Burger, 2004), Tasmania (Kiernan et al., 2001), and Croatia (Bočić et al., 2012). It has
also been observed at the present day in the limestone dominated catchments of the European Alps
(Gremaud et al., 2009). The karst system, therefore, has effectively by-passed the polje basins and
prevented reworking of the older Middle Pleistocene glaciofluvial sediments that fill the poljes. In
this respect, it has helped to preserve the oldest part of the Orjen outwash record (Fig. 6). Indeed,
these polje fills form one of the best-preserved archives of Middle Pleistocene glaciofluvial activity in
the Mediterranean. The sedimentary records within the Orjen and wider cave systems have not yet
been subjected to systematic investigation. The study of these records would provide a valuable
opportunity to test some of the ideas presented in this paper and establish correlations between the
surface and subterranean depositional records.
The Pleistocene fills in the wider Dinaric Karst
This section discusses the wider significance of the Pleistocene sedimentary records in the poljes
around Mount Orjen in the context of the regional Pleistocene glacial history in Montenegro and
across the classic karst landscapes of the Dinaric Alps in Croatia, Bosnia and Herzegovina, and
Slovenia. To the northeast of Mount Orjen, in the Durmitor Massif of central Montenegro, large
conjoined ice caps covered an area of nearly 1500 km2 – these were more than 10 times the size of
the largest ice mass on Mount Orjen. As in the case of Mount Orjen, the largest glaciation in central
Montenegro has been dated using U-series methods and is correlated with MIS 12 (Hughes et al.
2011). Ice lobes from these central Montenegrin ice caps fed into very large poljes such as at Nikšić
and Podgorica. Very extensive and thick deposits of coarse-grained outwash sediments were laid
down. The Nikšić polje is one of the largest poljes in Montenegro fed by Pleistocene glaciers. Several
smaller poljes in the Nikšić area were also filled with glacial outwash (Fig. 7).
The equilibrium line altitudes (ELAs) of the most extensive Pleistocene glaciers in Montenegro
ranged from c. 1200-1300 m a.s.l. on the coastal mountains at Orjen and Lovcen (Hughes et al. 2011;
Žebre and Stepišnik 2014) to c. 1600 m in the Durmitor Massif in central Montenegro. In all of these
12
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
areas glaciers advanced to altitudes below 1000 m, and sometimes as low as 500 m (Hughes et al.
2010). In the northern Dinaric Alps in Croatia, Marjanac et al. (2004) have presented evidence to
suggest that the most extensive glaciers extended even down to elevations equivalent to modern
sea level. It is clear that glaciers were present throughout the Dinaric Alps on many mountains that
exceeded 1000 m. Fig. 8 shows the regional topography and the distribution of the poljes. Much of
this landscape above 1000 m could have supported glaciers. By analogy with the well-dated glacier
records in Greece and Montenegro, we would argue that the most extensive phase of glaciation in
the Dinaric Alps also took place during MIS 12. It is therefore likely that the poljes of the Dinaric Alps
that were fed by large meltwater streams during this period were also filled with coarse-grained
outwash sediments in the same way as those we have observed in Montenegro. Indeed, since the
total area subjected to glaciation increases as one moves further north, the outwash sediment fluxes
to polje basins may have been even greater in more northerly parts of the Dinaric Alps than those in
Montenegro. If our findings in the poljes around Mount Orjen are representative of the wider karst
landscape in the Dinaric Alps, it may well be that many of the poljes of the Dinaric Alps, one of the
iconic features of this classic karst landscape, were filled with outwash during MIS 12 and there may
have been comparatively limited fluvial action in these basins since that time. Further research is
needed to test these ideas.
CONCLUSIONS
The eastern Mediterranean contains some of the world’s deepest and well-developed karst terrain.
Poljes are a distinctive feature of this landscape, but there has been only very limited investigation
into the nature and age of their Pleistocene sedimentary fills. Detailed sedimentological analysis and
U-series dating of the poljes surrounding the limestone massif of Orjen in western Montenegro has
established the nature and timing of polje infilling. More than forty years after Gams (1969) first
speculated on the potential role of glaciation and glaciofluvial processes as suppliers of sediment to
polje basins in this region, we have shown that the poljes around Mount Orjen were filled with
glacial outwash during the Middle Pleistocene. This represents the first detailed investigation of the
Pleistocene sedimentary record of multiple poljes that can be securely tied to the regional glacial
record. Many poljes in the Dinaric karst are situated downstream of uplands that were glaciated
during the Pleistocene. If the records we have studied in Montenegro are representative of the
wider region, many of the poljes of the Dinaric karst may also have been filled with glacial outwash
during MIS 12.
13
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
The Orjen massif preserves evidence of at least four phases of Pleistocene glaciation but polje filling
was dominated by the most extensive phase of glaciation that took place during the Middle
Pleistocene. During MIS 12, ice extended far beyond the plateau and into the surrounding poljes,
where thick (>10 m) sequences of coarse and fine-grained limestone-rich outwash were deposited.
During subsequent cold stages, glacier ice was restricted to the high altitude plateau above 1000 m
and outwash sediment supply was greatly diminished. Much of the glacial meltwater and outwash
sediment may have entered the sub-surface karst system during the less extensive phases of
glaciation. Indeed, there is no evidence of outwash sediment delivery to the lowland poljes after MIS
12. These polje fills provide some of the best-preserved archives of Middle Pleistocene outwash
sedimentation in the Mediterranean. The poljes of Orjen illustrate the important influence of the
limestone geology and associated glaciokarst system on the nature, source, transfer, deposition, and
preservation of the polje sedimentary records. By combining radiometric dating and detailed
sedimentological analysis, these depocentres are providing new insights into long-term glacial and
fluvial interactions in karst landscapes.
REFERENCES
Adamson, K. R., Woodward J. C., and Hughes P. D., 2014a, Glaciers and rivers: Pleistocene uncoupling in a Mediterranean mountain karst: Quaternary Science Reviews, v. 98, p. 28-43
Adamson, K. R., Woodward J. C., and Hughes P. D., 2014b, Glacial crushing of limestone and the production of loess in a Pleistocene proglacial system: Geografiska Annaler, v. 96, no. 3, p. 339–356.
Audra, P., Mocochain, L., Camus, H., Gilli, É., Clauzon, G., and Bigot, J. Y., 2004, The effect of the Messinian Deep Stage on karst development around the Mediterranean Sea. Examples from Southern France: Geodinamica Acta, v. 17, no. 6, p. 389-400.
Bakalowicz, M., El Hakim, M., and El-Hajj, A., 2008, Karst groundwater resources in the countries of eastern Mediterranean: the example of Lebanon: Environmental Geology, v. 54, p. 597–604.
Bavec, M., Tulaczyk, S. M., Mahan, S. A. and Stock, G. M., 2004, Late Quaternary glaciation of the Upper Soča River Region (Southern Julian Alps, NW Slovenia): Sedimentary Geology, v.165, p. 265-283
Birkeland, P. W., 1999, Soils and Geomorphology 3rd Edn: New York, Oxford University Press
Bočić, N., Faivre, S., Kovaičić, M., and Horvatinčić, N., 2012, Cave development under the influence of Pleistocene glaciation in the Dinarides – an example from Štirovača Ice Cave (Velebit Mt.,Croatia): Zeitschrift für Geomorphologie, v. 56, no. 4, p. 409–433.
Bogdan, G. and Leszek, L., 1999, Glaciokarst of subalpine and alpine zone of the Mala Laka Valley, Tatra Mts., Poland: Acta Carsologica, v. 28, no. 1, p.71-86
14
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499
Bognar, A., Faivre, S., and Pavelić, J., 1991, Tragovi oledbe na Sjevernom Velebitu: Geografski glasnik, v. 53, p. 27-39.
Bognar, A. and Faivre, S., 2006, Geomorphological Traces of the Younger Pleistocene Glaciation in the Central Part of the Velebit Mt: Hrvatski geografski glasnik, v. 68, no. 2, p. 19-30.
Bognar, A., Faivre, S., and Pavelić, J., 1992, Glaciation traces on the north Velebit: Hrvatski geografski glasnik, v. 53, no. 1, p.27-38.
Bognar, A., Faivre, S., Buzjak, N., Pahernik, M., and Bočić, N., 2012, Recent Landform Evolution in the Dinaric and Pannonian Regions of Croatia, in Lóczy, D. Stankoviansky, M., and Kotarba, A. eds. Recent Landform Evolution Springer Netherlands pp. 313-344.
Bonacci, O. 1987, Karst Hydrology with special reference to the Dinaric karst: Berlin, Springer pp. 184
Bonacci, O., Željković, I., and Galić, A., 2013, Karst rivers’ particularity: an example from Dinaric karst (Croatia/Bosnia and Herzegovina): Environmental Earth Sciences, v. 70, no. 2, p. 963-974.
Burger, P. A., 2004, Glacially-influenced sediment cycles in the Lime creek karst, Eagle County,Colorado, in Sasowsky, I. D., and Mylroie, J., eds., Studies of cave sediments: Physical and chemical records of paleoclimate: Kluwer Academic/Plenum Publishers, p. 107-122.
Civjić, J., 1898, Das Rilagebirge und seine ehemalige Vergletscherung: Zeitschrift der Gesellschaft für Erdkunde zu Berlin, v. 33, p. 200-253.
Civjić, J., 1900, L’Époque Glaciaire dans la Péninsule des Balkans: Annales de Géographie, v. 9, p. 359-372.
Cvijić, J., 1913, Ledeno doba u Prokletijama i okolnim planinama, v. XCI. Glas Srpske Kraljevske Akademije Nauka, Beograd, p. 1-149.
Cvijić, J., 1914, Eiszeitliche Vergletscherung der Gebirgsgruppen von Prokletije bis Durmitor. Maßstab 1:200,000. K.u.k. Militärgeographischen Institutes, Wien.
Cvijić, J., 1917. L’époque glaciaire dans la péninsule des Balkanique. Annales deGéographie, v. 26, p. 189-218.
Djurović, P. 2013, The Debeli Namet glacier from the second half of the 20th Century to the present: Acta geographica Slovenica, v. 52-2, p. 277–301. Djurović, P. and Petrović, A., 2007, Large canyons in the Dinaric and Prokletije Mountains region of Montenegro: Geographica Panoramica, v. 11, p. 14-18.
Ducić, V., Luković, J., Burić, D., Stanojevic, G., Mustafić, S., 2012, Precipitation extremes in the wettest Mediterranean region (Krivošije) and associated atmospheric circulation types: Natural Hazards and Earth Systems Science, v. 12, p. 687-697.
Ford, D. and Williams, P., 1989, Karst Geomorphology and Hydrology: London, Unwin Hyman
Ford, D. C. and Williams, P., 2007, Karst Hydrogeology and Geomorphology: Oxford, Wiley
15
500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550
Gabrovec M., 1998, The Triglav glacier between 1986 and 1998: Geografski zbornik v. 38, p. 89–110.
Gams, I., 1969, Some morphological characteristics of the Dinaric Karst: The Geographical Journal v. 135, no. 4, p. 563-572.
Gams, I., 1973, The terminology of the Types of Poljes: Slovenska kraška terminologija, p. 60 – 73.Ljubljana.
Gams, I., 1978, The polje: the problem of its definition: Zeitschrift für Geomorphologie, v. 22, p. 170-181.
Gams, I., 2005, Tectonics impact on poljes and minor basins (case studies of Dinaric karst): Acta Carsologica, v. 34, no. 1, p. 25-41.
Gremaud, V., Goldscheider, N., Savoy, L., Favre, G., and Masson, H., 2009, Geological structure, recharge processes and underground drainage of a glacierised karst aquifer system, Tsanfleuron-Sanetsch, Swiss Alps: Hydrogeology journal, v. 17(8), p. 1833-1848.
Groupe Spéléologique Muséum National d’Histoire Naturelle, Paris., 2003, Rapport de l’expédition le chemins d’Orjen 2003 organisée par Groupe Spéléologique Minos, Paris. Expédition du 30 juillet au 20 août 2003 au Monténégro (Crna Gora). 68 pp.
Hamdan, H., Kritikakis, G., Andronikidis, N., Economou, N., Manoutsoglou, E. and Vafidis, A., 2010, Integrated geophysical methods for imaging saline karst aquifers: A case study of Stylos, Chania, Greece: Journal of the Balkan Geophysical Society, v. 13, p. 1-8.
Hamdan, H., Economou, N. Kritikakis, G. Andronikidis, N., Manoutsoglou, E., Vafidis, A., Pangratis, P. and Apostolidou. G., 2012, 2D and 3D imaging of the metamorphic carbonates at Omalos plateau/polje, Crete, Greece by employing independent and joint inversion on resistivity and seismic data: International Journal of Speleology, v. 41, no. 2, p. 199-209
Harden, J. W., 1982, A quantitative index of soil development from field descriptions: examples from a chronosequence in central California: Geoderma, v. 28, p. 1-28.
Hughes, P. D., 2007, Recent behaviour of the Debeli Namet glacier, Durmitor, Montenegro:Earth Surface Processes and Landforms, v.10, p. 1593-1602.
Hughes, P. D., 2008, Response of a Montenegro glacier to extreme summer heatwaves in 2003 and 2007: Geografiska Annaler, v. 90, p. 259-267.
Hughes, P. D., 2009, Twenty-first century glaciers in the Prokletije mountains:Albania. Arctic, Antarctic and Alpine Research, v. 41, p. 455-459.Hughes, P. D. and Woodward, J. C., 2009, Glacial and Periglacial Environments, in Woodward, J. C., ed., The Physical Geography of the Mediterranean: Oxford, Oxford University Press pp. 353-383.
Hughes, P.D., Gibbard, P.L. and Woodward, J.C. 2004, Quaternary glaciation in the Atlas Mountains, North Africa. In: Ehlers, J. and Gibbard, P.L. (Eds) Quaternary Glaciation - Extent and Chronology. Volume 3: Asia, Latin America, Africa, Australia, Antarctica. Amsterdam: Elsevier. p. 255-260.
Hughes, P. D., Woodward, J. C., Gibbard, P. L., Macklin, M. G., Gilmour, M. A., and Smith, G. R.,2006, The glacial history of the Pindus Mountains, Greece: Journal of Geology, v. 114, p. 413-434.
16
551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592
593
594595596597598599600601602
Hughes, P. D., Woodward, J. C., van Calsteren, P. C., Thomas, L. E., and Adamson, K. R., 2010,Pleistocene ice caps on the coastal mountains of the Adriatic Sea: Quaternary Science Reviews, v. 29, no. 27-28, p. 3690-3708.
Hughes, P. D., Woodward, J. C., van Calsteren, P. C., and Thomas, L. E., 2011, The glacial history of the Dinaric Alps, Montenegro: Quaternary Science Reviews, v. 30, no. 3-24, p. 3393-3412.
Jennings, J. N., 1985, Karst Geomorphology Oxford: Blackwell
Kiernan, K., Lauritzen, S.-E. and Duhig, N., 2001, Glaciation and cave sediment aggradation around the margins of the Mt Field Plateau, Tasmania: Australian Journal of Earth Sciences, v. 48, p. 251–263.
Lewin, J., Macklin, M. G. and Woodward, J. C., 1991, Late Quaternary fluvial sedimentation in the Voidomatis Basin, Epirus, northwest Greece: Quaternary Research, v. 35, p. 103–115
Lewin, J. and Woodward, J. C., 2009, Karst Geomorphology and Environmental Change, in Woodward, J. C., ed., The Physical Geography of the Mediterranean: Oxford, Oxford University Press pp. 287-317.
Lewis, C. J., McDonald, E. V., Sancho, C., Peña, J. L., Rhodes, E. J., 2009, Climatic implications of correlated Upper Pleistocene glacial and fluvial deposits on the Cinca and Gállego Rivers (NE Spain) based on OSL dating and soil stratigraphy: Global and Planetary Change, v. 67, p. 141-152.
Liedtke, H., 1962, Eisrand und Karstpoljen am Westrand der Lukavica-Höchflache (Westmontenegro): Erdkunde, v. XV1, p. 289-298
López-Chicano, M., Calvache, M. L., Martın-Rosales, W., and Gisbert, J., 2002, Conditioning factors in flooding of karstic poljes—the case of the Zafarraya polje (South Spain): Catena, v. 49, no. 4, p. 331-352.
Magaš, D., 2002, Natural-geographic characteristics of the Boka Kotorska area as the basis of development: Geoadria, v. 7/1, p. 51-81.
Malez, M., Sokač, A., Šimunić, A., 1975, Quaternary sediments of Krbava polje in the Lika region. Acta Geologica VIII, p. 413-440
Marjanac, L., and Marjanac, T., 2004, Glacial history of the Croatian Adriatic and coastalDinarides., in Ehlers, J., Gibbard, P.L. eds., Quaternary Glaciations - Extent andChronology. Part I: Europe: Amsterdam, Elsevier, pp. 19-26.
Marković, S. B., Hambach, U., Catto, N., Jovanović, M., Buggle, B., Machalett, B., Zöller, L., Glaser, B. and Frechen, M., 2009, Middle and late Pleistocene loess sequences at Batajnica, Vojvodina, Serbia: Quaternary International, v. 198, no. 1, p. 255-266.
Messerli, B., 1967, Die eiszeitliche und die gegenwärtige Vergletscherung im Mittelmeerraum: Geographica Helvetica v. 22, p. 105-228
Milivojević, M., Menković, L. and Ćalic, J., 2008, Pleistocene glacial relief of the central part of Mt. Prokletije (Albanian Alps): Quaternary International, v. 190, p. 112-122
17
603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653
Mocochain, L., Clauzon, G., Bigot, J-V., and Brunet, P., 2006 Geodynamic evolution of the peri-Mediterranean karst during the Messinian and the Pliocene: evidence from the Ardèche and Rhône Valley systems canyons, Southern France: Sedimentary Geology, v. 188–189, p. 219–233.
Nicod, J., 1968, Premières recherches de morphologie karstique dans le massif duDurmitor (Crna Gora:Montenegro): Meditérraneé, v. 3, p. 187-216.
Nicod, J., 2003, A little contribution to the karst terminology: special of aberrant cases of poljes?: Acta Carsologica, v. 32, no. 2, p. 29-39.
Riđanović, J., 1966, Orjen. Travaux de L'institut de Geographie D'Universite de Zagreb, v. 5, p. 1-103
Sanders, E. M., 1921, The cycle of erosion in a karst region (after Cvijic): Geographical Review, v. 11, no. 4, p. 593-604.
Serrano, E., González-Trueba, J.J., Pellitero, R., González-García, M., Gómez-Lende, M., 2013. Quaternary glacial evolution in the Central Cantabrian Mountains (Northern Spain). Geomorphology, v. 196, p. 65-82.
Smart, P. L., 1986, Origin and development of glaciokarst closed depressions in the Picos de Europa, Spain: Zeitschrift für Geomorphologie, v. 30, p. 423–43.
Stepišnik, U., Ferk, M., Kodelja, B., Medenjak, G., Mihevc, A., Natek, K., Žebre, M., 2009, Glaciokarst of western Orjen: Cave and Karst Science, v. 36, p. 21-28.
Stepišnik, U. and Žebre, M., 2011. Glaciokras Lovčena. E-GeograFF 2. Univerza v Ljubljani, Filozofska fakulteta. Available at: http://geo.ff.uni-lj.si/sites/default/files/glaciokras_lovcena_0.pdf Last Accessed (April 25th 2014)
Stevens, T., Marković, S. B., Zech, M., Hambach, U., and Sümegi, P., 2011, Dust deposition and climate in the Carpathian Basin over an independently dated last glacial–interglacial cycle: Quaternary Science Reviews, v. 30, no. 5, p. 662-681.
Surić, M., Juračić, M., Horvatinčić, N. and Krajcar Bronić, I., 2005, Late Pleistocene–Holocene sea-level rise and the pattern of coastal karst inundation: records from submerged speleothems along the Eastern Adriatic Coast (Croatia): Marine Geology, v. 214, no. 1–3, p. 163–175.
Surić, M., Richards, D. A., Hoffmann, D. L., Tibljaš, D. and Juračić, M., 2009, Sea-level change during MIS 5a based on submerged speleothems from the eastern Adriatic Sea (Croatia): Marine Geology, v. 262, no. 1(1-4), p. 62–67.
Telbisz, T., 2010a, Morphology and GIS-analysis of closed depressions in Sinjajevina Mts (Montenegro): Karst Development: Original Papers 1, no. 1, 41-47.
Telbisz, T., 2010b, Glacio-karst features of the Sinjajevina Mts (Montenegro): an overview and DEM-Analysis: Karst Development, v. 1, p. 17-22.
Tisserant, J., 1974, Troisième campagne à l’Orjen (Yougoslavie – Monténégro 1976): Bulletin du Spéléo Club des Ardennes, v. 5, p. 1- 25.
18
654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704
van Andel, T. H. and Runnels, C. N., 2005, Karstic Wetland Dwellers of Middle Palaeolithic Epirus, Greece: Journal of Field Archaeology, v. 30, no. 4, p. 367-384.
Woodward, J C., Lewin, J., and Macklin, M.G., 1992. Alluvial sediment sources in a glaciated catchment: the Voidomatis basin, northwest Greece: Earth Surface Processes and Landforms, v. 17, p. 205-216
Woodward, J.C., Macklin, M. G. and Lewin, J. 1994, Pedogenic weathering and relative-age dating of Quaternary alluvial sediments in the Pindus Mountains of northwest Greece: Rock Weathering and Landform Evolution, p. 259-283.
Woodward, J. C., Macklin, M. G. and Smith, G. R., 2004, Pleistocene glaciation in the mountains of Greece, in Ehlers, J. and Gibbard, P. L., eds., Quaternary Glaciations – Extent and chronology Part 1: Europe: Amsterdam, Elsevier pp. 155-173.
Woodward, J.C., Lewin, J. and Macklin, M.G. 1995, Glaciation, river behaviour and Palaeolithic settlement in upland northwest Greece, in Mediterranean Quaternary River Environments, Rotterdam, Balkema, 115-129.
Woodward, J. C., Hamlin, R. H. B., Macklin, M. G., Hughes, P. D. and Lewin, J., 2008, Glacial activity and catchment dynamics in northwest Greece: Long-term river behaviour and the slackwater sediment record for the last glacial to interglacial transition: Geomorphology, v. 101, p. 44-67.
Wright, J. S., 2001, “Desert” loess versus “glacial” loess: quartz silt formation, source areas and sediment pathways in the formation of loess deposits: Geomorphology, v. 36, no. 3, p. 231-256.
Zahno, C., Akçar, N., Yavuz, V., Kubik, P. W. and Schlüchter, C., 2010, Chronology of Late Pleistocene glacier variations at the Uludağ Mountain, NW Turkey: Quaternary Science Reviews, v. 29, no. 9-10, p. 1173-1187.
Žebre, M. and Stepišnik, U. 2014, Reconstruction of Late Pleistocene glaciers on Mount Lovćen, Montenegro. Quaternary International. DOI: 10.1016/j.quaint.2014.05.006
Zöller, L., Glaser, B.,and Frechen, M., 2009, Middle and late Pleistocene loess sequences at Batajnica Vojvodina, Serbia: Quaternary International, v. 198, p. 255-266.
19
705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741
Figure 1 – Location map of the sites discussed in the text
20
742
743744745
746747
Figure 2 - The Pleistocene glacial and outwash records of Mount Orjen (after Hughes et al., 2010) and the surrounding poljes. Study sites and U-series ages (after Adamson et al., 2014a) are shown.
21
748749750
Figure 3 – Sediment logs along a transect of exposures in Dvrsno polje, east Orjen. The photographs show the coarse material deposited at the ice proximal side of the polje (Section D1), which fines downstream to interstratified sands and silt at Sections D6, and D8-D9. Facies codes follow the legend in Figure 4. See Figure 2 for transect locations.
22
751752753754755
Figure 4 – Sediment logs from poljes beyond the maximum MIS 12 ice margins surrounding the Orjen massif at: Pirina Poljana, north west Orjen; Kruševice and Vrbanje, west Orjen (see also inset photographs); and Grahovo, northeast Orjen.
23
756
757758759
760761762
Figure 5 - Sediment logs from poljes outside the maximum (MIS 12) Pleistocene ice margins and on the eastern margins of the Orjen massif, at Unijerina (see inset photograph), and Crkvice. Facies codes follow the legend in Figure 4.
24
763764765766767768769
Figure 6 – Schematic representation of the topographic and glaciokarst controls on sediment transfer pathways from the ice margins to the surrounding poljes during the Pleistocene
25
770771772773
774
775
776
Figure 7 – Map of the maximum Pleistocene ice margin and surrounding poljes on the southeastern margins of the Durmitor massif in central Montenegro.. Adapted from the work of Liedtke (1962). The Pleistocene ice limits in this part of Montenegro have recently been updated and dated by Hughes et al. (2011).
26
777
778779780781
782
783
784
Figure 8 - Map of the Dinaric karst showing the location of the major poljes (after Gams, 1969) in relation to the regional topography. A significant portion of the landscape above 1000 m has been affected by glacial processes – see text for discussion.
27
785
786787788
789
790
791
792
793
794
795
796
797
Polje typeGams (1973) Characteristics Polje type (Ford and
Williams, 1989)
Border Located at a geological contact and receives allogenic surface runoff.
BorderPiedmont Situated in an alluviated valley, downslope of glaciated terrain.
Peripheral Receives surface runoff from a large surface of rock.
OverflowUnderlain by relatively impermeable rock that acts as a dam forcing groundwater to flow at the polje surface towards stream sinks on the other side of the basin.
Structural
Base level The floor is cut entirely across karst rock and is located in the epiphreatic zone. Base level
Table 1 – Polje classifications based on the observations of Gams (1973) in the Dinaric karst of Slovenia, linked to the streamlined classifications of Ford and Williams (1989).
28
798
799
800801802803804
Polje Area (km2)
Exposure depth (m)
U-series age of secondary
carbonates (ka)Soil PDI Sediment fill characteristics
Beyond the MIS 12 ice margins and below c.1,000 m a.s.l.
Dvrsno 7.5 10 -
11.80(proximal
)7.35
(distal)
Massive limestone sands and gravels, fining with distance from the ice margin. Sand and silt lenses become increasingly abundant in the centre of the polje.
Grahovo 7.0 3 >350 8.91 Massive limestone sands and gravels with some sand and silt horizons.
Pirina Poljana 20.5 4 213.5 ± 11.377.2 ± 2.0 9.12 Massive to stratified limestone sands and
gravels. Weakly cemented.
Kruševice 0.6 9 - 13.75Massive limestone sands and gravels, fining with distance from the ice margin. Sand and silt lenses abundant.
Vrbanje 2.8 7 126.6 ± 4.5 4.88 Massive to stratified limestone sands and gravels. Weakly cemented.
Within the MIS 12 ice margins and at the edge of the Orjen plateau
Unijerina 0.5 11
>350248.6 ± 16.7
80.3 ± 5.916.6 ± 0.4
6.29 (diamict)
1.43(alluvium)
Multiple facies: well-stratified sands and gravels with abundant silt and clay interstratifications; and massive matrix-supported diamicton.
Crkvice 1.7 2 144.2 ± 5.118.5 ± 0.4
3.92(diamict)
4.12(alluvium)
Multiple facies: well-stratified sands and gravels with abundant silt and clay interstratifications; and massive matrix-supported diamicton.
Table 2 – Summary of the main morphological, sedimentological and chronological features of the polje fills around Mount Orjen. Based on data presented in Adamson et al. (2014a).
29
805
806807808
