DOI: 10.1016/j.quascirev.2015.03.017
Scopus记录号: 2-s2.0-84926432161
论文题名: Late Pleistocene piedmont glaciations in the Eastern Mediterranean; insights from cosmogenic 36Cl dating of hummocky moraines in southern Turkey
作者: Çiner A. ; Sarikaya M.A. ; Yildirim C.
刊名: Quaternary Science Reviews
ISSN: 2773791
出版年: 2015
卷: 116 起始页码: 44
结束页码: 56
语种: 英语
英文关键词: Geyikdağ
; Hummocky moraine
; Last Glacial Maximum
; Late-glacial
; Paleoclimate
; Piedmont glacier
; TCN dating
; Younger Dryas
Scopus关键词: Climate change
; Glacial geology
; Sea level
; Hummocky moraines
; Last Glacial Maximum
; Late-glacial
; Paleoclimates
; TCN dating
; Younger Dryas
; Landforms
; cosmogenic radionuclide
; glacial debris
; glacial landform
; glaciation
; hillslope
; moraine
; piedmont
; Pleistocene
; Turkey
英文摘要: We report the presence of Late Pleistocene piedmont glaciers represented by the largest hummocky moraine field observed in the Eastern Mediterranean. The piedmont glaciers originated from the Geyikdağ ice cap (~40km2), situated between 2350 and 2650m above sea level (a.s.l.) (Central Tauride Mountains of Turkey), and deeply carved the north-facing hillslopes before reaching the Namaras Valley (2000-2050m a.s.l). The hummocky moraines resulted from in-situ deposition of stagnant glacier ice where debris cover was heterogeneously distributed on the glacier surface. Thirty-four boulders from hummocky, disintegration, lateral and terminal moraines from the Namaras Valley and the tributary Susam Valley (2100-2200m a.s.l.) were dated by cosmogenic 36Cl surface exposure dating. The moraine ages indicate three phases of deglaciation during the Late Pleistocene. The oldest deglaciation occurred in the Namaras Valley at 18.0±1.1ka (ka: thousand years ago) towards the end of the Last Glacial Maximum (LGM) and is recorded entirely by hummocky moraines. We speculate that hummocky moraine forming processes with cycles of relief inversion gave rise to boulder apparent ages up to a few thousand years younger in our study area. Therefore, 18.0±1.1ka should be regarded as a minimum age with a probable true age much closer to the local-LGM values (~20ka) as observed in the surrounding mountains. Paleo-piedmont glaciers also deposited several lateral moraines that are ~50m higher than the hummocky moraines. Although the lateral moraines probably represent the build-up and the hummocky moraines the final phase of the same local-LGM-pulse, both lateral moraines started to retreat from the Late-glacial (14.0±2.7ka) and gradually disappeared by mid-Holocene (5.2±1.0ka), encompassing the Younger Dryas (YD) stadial. In the Susam Valley, the Late-glacial is represented by a terminal moraine (13.4±1.5ka). The glacier retreat was very fast as indicated by an almost instantaneous disappearance of 5km long Susam Valley glacier, represented by disintegration and hummocky moraines (14.0±1.3ka). Alternatively, in case the oldest boulder age is taken into account, the Susam Valley glacier can be also attributed to the late LGM (~17ka) to Late-glacial (~14ka) transition. Near the exit of the Susam Valley a right lateral moraine was deposited 11.6±1.3ka ago, confirming the presence of the YD in Geyikdağ. Comparable glacial chronologies were obtained from other Turkish and Mediterranean mountains. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/59947
Appears in Collections: 过去全球变化的重建
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作者单位: Eurasia Institute of Earth Sciences, Istanbul Technical University, Maslak-Istanbul 34469, Turkey
Recommended Citation:
Çiner A.,Sarikaya M.A.,Yildirim C.. Late Pleistocene piedmont glaciations in the Eastern Mediterranean; insights from cosmogenic 36Cl dating of hummocky moraines in southern Turkey[J]. Quaternary Science Reviews,2015-01-01,116