Open AccessHumification degrees of a lacustrine sedimentary sequence as an indicator of past climatic changes in the last c . 49 000 years in South China
Author(s) -
ZHONG WEI,
MA QIAOHONG,
XUE JIBIN,
ZHENG YANMING,
CAI YING,
OU YANGJUN
Publication year - 2010
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/j.1502-3885.2009.00119.x
Subject(s) - stalagmite , geology , swamp , sedimentary rock , period (music) , sedimentary organic matter , monsoon , precipitation , total organic carbon , glacial period , organic matter , physical geography , humus , east asian monsoon , δ13c , climatology , holocene , paleontology , stable isotope ratio , geography , ecology , soil science , soil water , biology , physics , quantum mechanics , meteorology , acoustics
Zhong, W., Ma, Q. H., Xue, J. B., Zheng, Y. M., Cai, Y. & Ou, Y. J. 2009: Humification degrees of a lacustrine sedimentary sequence as an indicator of past climatic changes in the last c . 49 000 years in South China. Boreas , 10.1111/j.1502‐3885.2009.00119.x. ISSN 0300‐9483. An 860 cm long sediment core recovered from Dahu Swamp was used to test the potential of the degree of humification (expressed as the corrected absorbance values, HD cab ) of lacustrine sediments as an indicator of past climatic changes in South China. The chronological sequence of this core was established using 10 AMS 14 C dates and 10 conventional 14 C dates and gives the bottom age of c . 48 800 cal. yr BP. Based on comparisons with multiproxy records, such as lithological variation, organic carbon isotope ratio, organic matter content and dry bulk density, we infer that the HD cab record is sensitive to local hydrological variations that are closely related to the East Asian (EA) summer monsoon precipitation. Higher HD cab values would indicate relatively drier conditions, suggesting a weakening of the EA summer monsoon and vice versa. Based on the HD cab , as well as other multiproxies, the climatic history in the last c . 49 000 years in the swamp area shows agreement with the Chinese stalagmite record and with the 25°N summer solar insolation, implying that orbitally induced insolation may have played a role in the last glacial period (LGP) climate in South China. Several millennial‐scale dry phases during the LGP show similarities with the stadials revealed by the ice core record in Greenland and from the Chinese cave stalagmites. Our study demonstrates that the HD cab of lacustrine sediments is a useful proxy of past climatic changes in South China.