Textural and carbon isotopic evidence of monsoonal changes recorded in a composite-type speleothem from Korea since MIS 5a

Kyoung nam Jo, Kyung Sik Woo, Hai Cheng, Larry Edwards, Yongjin Wang, Ryeon Kim, Xiuyang Jiang

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

Textural and stable isotopic records of a composite-type speleothem from Gwaneum Cave in the eastern part of the Korean peninsula show prominent paleoenvironmental changes since MIS (marine oxygen isotope stage) 5a. Based on 230Th/234U dating, the speleothem experienced growth from 90.9±6.5ka to 1.2±0.5ka with several hiatuses. Four growth phases (A, B, C and D) are recognized based on speleothem type and texture. Very irregular and laterally discontinuous growth laminae in Phases B and C indicate that the cave coralloids grew over the stalagmite (Phase A) when the supply of dripping water became limited. Variations within the δ13C time series of Phase A are interpreted as responses to millennial-scale fluctuations of the East Asian monsoon intensity during MIS 5a. The monsoonal interpretation is based on the idea that δ13C values reflect the isotopic composition of soil-derived CO2, which, in turn, should relate to monsoon-driven changes in terrestrial productivity above the cave during the MIS 5a. Our reconstruction reveals that the significant monsoonal changes on the Korean peninsula occurred in conjunction with changes in sea level and/or oceanic circulations during the transition period from MIS 5a to MIS 4.

Original languageEnglish (US)
Pages (from-to)100-112
Number of pages13
JournalQuaternary Research
Volume74
Issue number1
DOIs
StatePublished - Jul 1 2010

Keywords

  • East Asian monsoon
  • Korean peninsula
  • MIS 5a
  • Speleothem
  • Stable isotope

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