Paleo-glaciations of the Shaluli Shan, southeastern Tibetan Plateau
Abstract
Reconstructing regional paleoclimates of the Tibetan Plateau is critical to understanding linkages between regional climate changes and global climate changes; here we focus on the paleo-glaciations of the Shaluli Shan, situated on the southeastern margin of the Tibetan Plateau that receives much of its precipitation from monsoon flow. The Quaternary glacial history of the Shaluli Shan area in the southeastern region of the Tibetan Plateau is examined by geomorphologic mapping, field investigation, and 10Be terrestrial cosmogenic nuclide (TCN) dating. Our geomorphologic studies provide the first detailed glacial landform map of this region, where the glacial landforms are characterized by extensive Alpine glacial landforms centered on high mountain ranges, and zonal distributions of glacial landforms on low relief plateaus, indicating regional, polythermal ice caps. Combining the TCN ages, glaciations with diminishing size are identified: Post-global Last Glaciation Maximum (17-13 ka), global Last Glaciation Maximum (21-17 ka) and older glaciations during MIS 6 or older stage. During the older glaciations, significant ice caps covered the Haizishan Plateau and Xinlong Plateau with large outlet glaciers extending far down outlet valleys, and extensive valley glaciers and piedmont glaciers in the high mountains. During the global Last Glaciation Maximum (gLGM), ice caps and/or ice fields were present on the Haizishan and Xinlong plateau surfaces, in stark contrast to more central regions of the Tibetan Plateau where there was very limited ice expansion during the gLGM. Given the location of the Shaluli Shan area, this work provides insights into the paleoclimate pattern and monsoon evolution of the Tibetan Plateau. It shows that the Shaluli Shan has a glacial chronology more consistent with the Northern Hemisphere paleo ice sheets than other areas of the Tibetan Plateau.
Degree
M.S.
Advisors
Harbor, Purdue University.
Subject Area
Geomorphology
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