A penultimate glacial monsoon record from Hulu Cave and two-phase glacial terminations
- Hai Cheng*1,
- R. Lawrence Edwards2,
- Yongjin Wang3,
- Xinggong Kong3,
- Yanfang Ming3,
- Megan J. Kelly4,
- Xianfeng Wang4,
- Christina D. Gallup5 and
- Weiguo Liu6
- 1Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA, and College of Geography Science, Nanjing Normal University, Nanjing 210097, China
- 2Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
- 3College of Geography Science, Nanjing Normal University, Nanjing 210097, China
- 4Department of Geology and Geophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
- 5Department of Geological Sciences and Large Lakes Observatory, University of Minnesota Duluth, Duluth, Minnesota 55812, USA
- 6Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710054, China
Abstract
Oxygen isotope records of three stalagmites from Hulu Cave, China, extend the previous high-resolution absolute-dated Hulu Asian Monsoon record from the last to the penultimate glacial and deglacial periods. The penultimate glacial monsoon broadly follows orbitally induced insolation variations and is punctuated by at least 16 millennial-scale events. We confirm a Weak Monsoon Interval between 135.5 ± 1.0 and 129.0 ± 1.0 ka, prior to the abrupt increase in monsoon intensity at Asian Monsoon Termination II. Based on correlations with both marine ice-rafted debris and atmospheric CH4 records, we demonstrate that most of marine Termination II, the full rise in Antarctic temperature and atmospheric CO2, and much of the rise in CH4 occurred within the Weak Monsoon Interval, when the high northern latitudes were probably cold. From these relationships and similar relationships observed for Termination I, we identify a two-phase glacial termination process that was probably driven by orbital forcing in both hemispheres, affecting the atmospheric hydrological cycle, and combined with ice sheet dynamics.
Footnotes
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↵* Corresponding author cheng021{at}umn.edu
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↵GSA Data Repository item 2006040, Figures DR1–DR5 and Tables DR1–DR2, is available online at www.geosociety.org/pubs/ft2006.htm, or on request from editing{at}geosociety.org or Documents Secretary, GSA, P.O. Box 9140, Boulder, CO 80301-9140, USA.
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- Accepted 16 November 2005.
- Received 10 October 2005.
- Revision received 14 November 2005.
- Geological Society of America
