Lake-level records support a mid-Holocene maximum precipitation in northern China  

作　　者：Jiantao CAO Zhiguo RAO Fuxi SHI Ergang LIAN Guodong JIA 

机构地区：[1]State Key Laboratory of Marine Geology,Tongji University,Shanghai,200092,China [2]Key Laboratory of Ecological and Environmental Change in Subtropical Zone,College of Geographic Science,Hunan Normal University,Changsha,410081,China [3]Wuyishanxipo Observation and Research Station of Forest Ecosystem,Key Laboratory of State Forestry Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed,College of Forestry,Jiangxi Agricultural University,Nanchang,330045,China

出　　处：《Science China Earth Sciences》2021年第12期2161-2171,共11页中国科学（地球科学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(Grant Nos.42171156&42003055).

摘　　要：Lake level and its inferred East Asian summer monsoon(EASM)evolution in northern boundary of EASM during the Holocene are highly debated.Here,we present a 15-ka record of glycerol dialkyl glycerol tetraethers(GDGTs)in a closed lake in northern China to address this issue.Surface and downcore sediment data demonstrate sedimentary GDGT-0 and branched GDGTs(brGDGTs)are of aquatic production.Contents of GDGT-0 and brGDGTs increase but brGDGT-based paleo-temperature proxy decreases with water depth in surface sediments along a nearshore to offshore transect.This trend is likely due to an increasingly hypoxic condition,favored by anaerobic microbes producing these GDGT-0 and brGDGTs,in bottom water.Accordingly,brGDGT-derived water temperature and pH would reflect bottom water conditions that are largely regulated by water depth of the lake.Downcore GDGT data and their derived temperature and pH consistently reveal a gradually increasing lake level from the late Pleistocene to the early Holocene,a high level during 9.5-5 ka BP and a decreasing trend afterward.The lake-level records from independent and robust proxies in this study largely agree with pollen records in the region,supporting a mid-Holocene maximum EASM precipitation.

关 键 词：Lake level membrane lipids East Asian summer monsoon HOLOCENE northern China 

分 类 号：P426.6[天文地球—大气科学及气象学]