The glacial history of the Tibetan Plateau has long been a contentious topic with widely different reconstructions. For Tanggula Shan, an extensive mountain range on the central Tibetan Plateau, multiple glacial reconstruc- tions and studies on the glacial chronology have been presented. However, the glacial geomorphological record has been sparse resulting in insufficient data to fully infer the area’s palaeoglaciology. Focussing on four landform categories, glacial valleys, marginal moraines, hummocky terrain, and glacial lineations; a glacial geomorphological map was produced, using Landsat 7 ETM+ satellite imagery, SRTM digital elevation model, and Google Earth. This map, together with GIS analyses and available cosmogenic exposure and electron spin reso- nance ages from the study area, was used to investigate the extent of former glaciations. Cosmogenic exposure and electron spin resonance ages range from 18.4 ± 1.6 to 203.4 ± 33.2 ka (recalculated using the CRONUS calculator). The extent of the glacial footprint is restricted to the high mountain areas, and is similar in extent to earlier glacial reconstructions. This glacial footprint can tentatively be explained by a monsoonal influence in the southeast, with the influence diminishing to the northwest. Alternatively, the precipitation gradient might have resulted in cold-based ice in the west and warm-based ice in the east. These variations in ice regime could have left fewer traces of glaciation in the west, than in the east. There is no evidence supporting an ice sheet covering the entire Tibetan Plateau. Rather, the available data support a smaller ice field in the high mountain areas, with a maximum extent well before the Last Glacial Maximum.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:su-43145 |
| Date | January 2010 |
| Creators | Morén, Björn |
| Publisher | Stockholms universitet, Institutionen för naturgeografi och kvartärgeologi (INK) |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/masterThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
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