A multi-proxy record of environmental changes during the Holocene from the Haolaihure Paleolake sediments, Inner Mongolia

The east Central Inner Mongolia is located near the present-day limit of the Asian Summer Monsoon (ASM) influence and therefore sensitive to both regional and global climate change. Here, we present the high-resolution proxy record of regional paleoclimate evolution over the past 12.2 cal ka BP, based on analyses of grain size and organic geochemical proxies (i.e., TOC, TN, C/N, delta C-13 and delta N-15) preserved in sediments from the Haolaihure Paleolake. The multi-proxy record reveals a cool and dry period from 12.2 to 8.7 cal ka BP and a relatively warm and wet stage from 8.7 to 2.2 cal ka BP, interrupted by a short interval of reduced precipitation at 4.6-3.7 cal ka BP. After 2.2 cal ka BP, the regional environment deteriorated as climate shifted to generally cooler and drier conditions in the area, with a brief return to a warm and wet climate during the MedievalWarm Period. The record also indicates severe drought in the region during the Younger Dryas event. Comparison with other proxy paleoclimate records in Inner Mongolia, South China and central Asia suggests that the environmental conditions in the east central Inner Mongolia were primarily controlled by the ASM in the early to mid-Holocene while the Westerlies appeared to be a major driver of environmental changes in the late Holocene. Six of the eight cool and dry events recorded in Haolaihure Paleolake sediments are in phase with the ice-rafting events in the North Atlantic, and were possibly caused by weakening of both the ASM and the Westerlies. (C) 2017 Elsevier Ltd and INQUA. All rights reserved.