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A Late Quaternary Climate Record Based on Multi‐Proxies Analysis from the Jiaochang Loess Section in the Eastern Tibetan Plateau, China
Author(s) -
Song BAI,
Ya TANG,
Chengshan WANG,
Chengmin HUANG
Publication year - 2007
Publication title -
acta geologica sinica ‐ english edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 61
eISSN - 1755-6724
pISSN - 1000-9515
DOI - 10.1111/j.1755-6724.2007.tb01030.x
Subject(s) - plateau (mathematics) , organic matter , monsoon , transect , quaternary , total organic carbon , carbonate , glacial period , climate change , arid , tropical monsoon climate , climatology , δ13c , loess , geology , physical geography , environmental science , stable isotope ratio , geomorphology , environmental chemistry , geography , chemistry , oceanography , paleontology , mathematical analysis , physics , mathematics , organic chemistry , quantum mechanics
Abstract: We compared the stable carbon isotopic records from a loess transect of the Jiaochang in the eastern Tibetan Plateau, spanning the last ∼21,000 years, with multiproxy data for pedogenesis, including magnetic susceptibility, clay fraction, Fe d /Fe t ratio, carbonate and total organic carbon content, in order to probe the mechanisms of δ 13 C values of organic matter and Late Quaternary climate variations in the eastern Tibetan Plateau. Our results indicate that there is no simple relationship between δ 13 C of organic matter and summer monsoon variations. The change in δ 13 C values of organic matter (in accordance with the ratios of C 3 to C 4 plants) results from the interaction among temperature, aridity and atmospheric p CO 2 level. Drier climate and lower atmospheric p CO 2 level contribute to positive carbon isotopic excursion, while negative carbon isotopic excursion is the result of lower temperature and increased atmospheric p CO 2 level. Additionally, our results imply that the Tibetan monsoon may play an important role in climate system in the eastern Tibet Plateau, which specifically reflects frequently changing climate in that area. The results provide new insights into the forcing mechanisms on both the δ 13 C values of organic matter and the local climate system.