Climate variability recorded by n-alkanes of paleolake sediment in Qaidam Basin on the northeast Tibetan Plateau in late MIS3

• DOI: 10.1007/s11430-010-0075-2
• Publication Date: 2010-05-17T21:20:57Z
• Authors: Yang Pu; HuCai Zhang; GuoLiang Lei; FengQin Chang; MingSheng Yang; WenXiang Zhang; YanBin Lei; LunQing Yang; YouZhi Pang
• Keywords: 13. Climate action; 01 natural sciences; 0105 earth and related environmental sciences

Here we combine n-alkanes preserved in a shell bar section from Qarhan paleolake, Qaidam Basin with the other sedimentary proxies to elucidate the lake evolution process during the period 39.7 to 17.5 14C ka BP (calibrated age ranges from 43.5 to 22.4 cal. ka BP). In different stages, the n-alkane homologues exhibited different distribution modes indicative of variations in the surrounding vegetation and the hydrologic condition of the lake. The n-alkanes proxies (CPIh, ACLh, Paq) have the same trends as the summer solar insolation variation, implying that the summer insolation is the most important climatic factor driving the environmental changes and also indirectly controls lake evolution on the Tibetan Plateau. CPIh and ACLh as well as the total pollen concentration appear to show a trend comparable with methane concentration record from the GRIP ice core that reflected the Dansgaard-Oeschger events. This demonstrates that the paleoclimate variations in Qarhan area generally agree with global climate change and show rapid oscillations in late MIS3. These findings provide the latest molecular fossil evidence from paleolake sediments to confirm that lake evolution on Tibetan Plateau in late MIS3 was closely associated with enhanced summer insolation.