Late Pleistocene glaciations at Lake Donggi Cona, eastern Kunlun Shan (NE Tibet): early maxima and a diminishing trend of glaciation during the last glacial cycle

Abstract

2017 (July): Late Pleistocene glaciations at Lake Donggi Cona, eastern Kunlun Shan (NE Tibet): early maxima and a diminishing trend of glaciation during the last glacial cycle.The Burhan Budai Shan in NE Tibet represents a key location for examining the variable influence of the midlatitude westerly and monsoonal circulations on late Quaternary glaciations in this sector of the Tibetan Plateau. Our study investigates the glacial history of mountains near Lake Donggi Cona (35°17 0 N, 98°33 0 E) using field mapping in combination with 10 Be surface exposure dating and numerical reconstructions of former glacial equilibrium line altitudes (palaeo-ELA). A set of 23 new exposure ages, collected from moraines in four glacial valleys, ranges from 45 to 190 ka, indicating ice expansion during the early and middle part of the last glacial cycle, and during the penultimate and possibly an earlier Mid-Pleistocene glaciation. Ice advances reaching 12-15 km in length occurred at around 190-180 ka (≥MIS 6), between 140-100 ka (late MIS 6/MIS 5), and 90-65 ka (late MIS 5/early MIS 4), with a maximum ELA depression of 400-500 m below the estimated modern snowline. Exposure ages from the valley headwaters further indicate a small glaciation between c. 60-50 ka (late MIS 4/early MIS 3), which was essentially restricted to the cirque areas. Significantly, we find no evidence for any subsequent glaciation in the area during MIS 2 or the Holocene period. These results indicate a diminishing trend of glaciation in the region since at least MIS 4, and corroborate the case of a 'missing LGM' in the more interior parts of the northeastern Tibetan Plateau. The emerging pattern suggests that the most favourable conditions for glaciation during the Late Pleistocene correspond to periods of relatively moderate cooling combined with an intermediate or rising East Asian monsoon strength.

Chronology and climate sensitivity of the post‐LGMglaciation in the Dunagiri valley, Dhauliganga basin, Central Himalaya, India

“…; Rother et al . ). It has been widely used to ascertain present and palaeo‐ELA depression (Porter ; Owen et al .…”

Neotectonic Subsidence Along the Cenozoic Kunlun Fault (Tibetan Plateau)

“…23‐20 cal. ka BP) probably correspond to fluvial deposits which were connected with youngest lateral moraines in the northern catchment dated to between 80 and 62 ka (Rother et al., 2017), enhanced by the melting process afterward.…”

Late quaternary glacial history of the La Ji Shan: Implications for the LGM on the northeastern Tibetan Plateau

“…However, the La Ji Shan, which is also located in the northeastern Tibetan Plateau, experienced a glacial advance during the LGM (Owen et al, 2003b;Murari et al, 2014). The annual precipitation in the La Ji Shan (200-400 mm; Owen et al, 2003b) is similar to that in the Bayan Har Shan (300-500 mm; Heyman et al, 2011) and Lake Donggi Cona (300-350 mm; Rother et al, 2017) areas, although the highest peak in the La Ji Shan (4898 m asl) is lower than that in the Bayan Har Shan (5267 m asl) and Lake Donggi Cona (5029 m asl) areas (Figure 1B). As such, other factors (e.g., relief and temperature) should be considered to determine the reason for the lack of the LGM glacial advance in the Bayan Har Shan and Lake Donggi Cona areas.…”

“…Previous studies have shown that the Bayan Har Shan (Heyman et al, 2011) and Lake Donggi Cona (Rother et al, 2017) areas, which are located in the interior of the northeastern Tibetan Plateau (Figure 1A), were unglaciated during the Last Glacial Maximum (LGM). However, on the northeastern Tibetan Plateau, based on 10 Be exposure ages, glacial advance occurred during the LGM in some regions (e.g., Qilian Shan (Cui, 2017;Owen et al, 2003c) and the Anyemaqen area (Owen et al, 2003a).…”

“…However, on the northeastern Tibetan Plateau, based on 10 Be exposure ages, glacial advance occurred during the LGM in some regions (e.g., Qilian Shan (Cui, 2017;Owen et al, 2003c) and the Anyemaqen area (Owen et al, 2003a). Rother et al (2017) suggested that this was because of the drier and lower altitudes of the Bayan Har Shan and Lake Donggi Cona areas, compared with these two regions. However, the La Ji Shan, which is also located in the northeastern Tibetan Plateau, experienced a glacial advance during the LGM (Owen et al, 2003b;Murari et al, 2014).…”