Lake Level and Climate Changes between 42,000 and 18,000 ¹⁴C yr B.P. in the Tengger Desert, Northwestern China

Abstract

Multiple lines of stratigraphic, geochemical, and fossil data suggest that fresh-mesohaline paleolakes were widespread in the Tengger Desert of northwestern China and underwent major fluctuations during the late Pleistocene. The paleolakes started to develop at ca. 42,000 14C yr B.P. The lake levels were the highest between 35,000 and 22,000 14C yr B.P., during which Megalake Tengger dominated the landscape. The climatic conditions at this time were unique for this area and have no modern analogue. After an episode of decline between 22,000 and 20,000 14C yr B.P. and an episode of rebound between 20,000 and 18,600 14C yr B.P., the paleolakes started to desiccate and completely disappeared around 18,000 14C yr B.P. The environmental proxy data indicate that the Megalake Tengger formed under warm–humid climates. The reconstructed climatic variations appear to be correlative with the abrupt climatic events reconstructed for the North Atlantic.

AMS Dating on the Shell Bar Section from Qaidam Basin, Ne Tibetan Plateau, China

“…It reveals geological facts that indicate the existence of a huge uniform paleolake in the area, which is an indication of the readjustments and changes in the regional climate. This conclusion is consistent with study results in other arid areas in NW China (Peng et al 1998;Zhang et al 2001Zhang et al , 2002Zhang et al , 2004 and supports the Thompson et al (1997) Guliya ice-core study results in the western Tibetan Plateau. The fossil shells preserved in the sediments indicate a mild, warm climate suitable for Corbicula.…”

Palaeo-moisture evolution in monsoonal Central Asia during the last 50,000 years

“…Further evidence of a comparatively wet period on the Tibetan Plateau at this time comes from dated lake sediments, which indicate lake levels above the present-day conditions for example, in western Tibet at Tianshuihai (Li et al, 1991), Akesaiqin (Fang, 1991), Bangong Co (Li et al, 1991) and in central Tibet at Zabuye Lake and Selin Co (Li et al, 1991). Large lakes, which have been reported for the Qaidam Basin (Chen and Bowler, 1986) and the Alashan Plateau (Pachur et al, 1995;Wu¨nnemann et al, 1998a, b;Zhang et al, 2002) do not prove that similar wet conditions prevailed also in other areas of north-west China, since these lakes have been fed by rivers which originate in the Tibetan Plateau or in bordering mountain ranges. The occurrence of such extended lakes, however, is further evidence for strongly increased precipitation values over the Tibetan Plateau area itself.…”

Branched aliphatic alkanes of shell bar section in Qarhan Lake, Qaidam Basin and their paleoclimate significance

“…Kenig et al [22] suggest that the paleoenvironmental distribution of these compounds points to nonphotosynthetic, thermophollic bacteria living at redox boundaries. Because such thermophollic bacteria live in mild-warm conditions and bear important climate signal for paleolake research in Northwest China [23][24][25] .…”