Xinya Cave, China Glacial Speleothem Oxygen Isotope Data Li, T.-Y.; Yuan, D.X.; Li, H-C.; Yang, Y.; Wang, J.L.; Wang, X.Y.; Li, J.Y.; Qin, J.M.; Zhang, M.L.; Lin, Y.S. Li, T.-Y. Yuan, D.X. Li, H-C. Yang, Y. Wang, J.L. Wang, X.Y. Li, J.Y. Qin, J.M. Zhang, M.L. Lin, Y.S. Monsoon earth science/paleoclimate/speleothems (depth,null,null,millimeter,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (age,null,null,calendar kiloyear before present,null,speleothems,null,null,N,null) earth science/paleoclimate/speleothems (delta 18O,calcium carbonate,null,per mil PDB,null,speleothems,raw,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/speleothems (Xinya Cave>LATITUDE 30.75>LONGITUDE 109.4667) A 26-cm-long stalagmite (XY2) from Xinya Cave in northeastern Chongqing of China has been ICP-MS 230Th/U dated, showing a depositional hiatus at 2.3 cm depth from the top. The growth of the 2.3-26 cm interval determined by four dates was between 57 ka and 70 ka, with a linear growth rate of 0.023 mm/a. We have analyzed 190 samples for d18O and d13C, mostly in the 2.3-26 cm part. The d18O and d13C values between 57 ka and 70 ka reveal decadal-to-centennial climatic variability during the glacial interval of Marine Isotope Stage 4 (MIS4), exhibiting much higher resolution than that of the published Hulu and Dongge records during this interval. Speleothem d18O in eastern China, including our study area can be used as a proxy of summer monsoon strength, with lighter values pointing to stronger summer monsoon and higher precipitation, and vice versa. Two decreases in the d18O signature of XY2 record around 59.5 and 64.5 Ka are argued to correspond to the Dansgaard-Oeschger (D-O) events 17 and 18 respectively. The Heinrich event 6 (H6) can be identified in the record as a heavy d18O peak around 60 ka, indicating significant weakening of the monsoon in Chongqing during the cold period. The XY2 d18O record shows very rapid change toward to the interstadial condition of the D-O event, but more gradual change toward to the cold stadial condition. This phenomenon found in the Greenland ice core records is rarely observed so clearly in previously published speleothem records. According to SPECMAP d18O record, the glacial maximum of MIS 4 was around 64.5 ka with the boundary of MIS 3/4 around 60 ka. Unlike the marine record, the speleothem record of XY2, China, exhibits much high frequency variations without an apparent glacial maximum during MIS 4. However, the timing of MIS 3/4 boundary seems to be around 60 ka when the H6 terminated, in agreement with the marine chronology. The growth period of sample XY2 during glacial times probably reflects a local karstic routing of water, rather than having climatic significance. STUDY NOTES: Speleothem oxygen isotope data from a 26-cm-long stalagmite (XY2) from Xinya Cave in south China. Stalagmite XY2 is ICP-MS 230Th/U dated to between 57 ka and 70 ka. The d18O values reveal decadal- to-centennial climatic variability during the glacial interval of Marine Isotope Stage 4 (MIS4). Heinrich event 6, and Dansgaard- Oeschger (D-O) events 17 and 18 can be determined by the XY2 d18O records, which are higher resolution than previous records in China. NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Li, T.-Y. Investigator : Yuan, D.X. Investigator : Li, H-C. Investigator : Yang, Y. Investigator : Wang, J.L. Investigator : Wang, X.Y. Investigator : Li, J.Y. Investigator : Qin, J.M. Investigator : Zhang, M.L. Investigator : Lin, Y.S. 2010-07-08 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/10444 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xinya2007.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xinya2007.xls https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xinya2007.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xinya2007.xls English https://www.ncdc.noaa.gov/paleo/study/10444 https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xinya2007.txt https://www1.ncdc.noaa.gov/pub/data/paleo/speleothem/asia/china/xinya2007.xls Li, T.-Y., D.X. Yuan, H.C. Li, Y. Yang, J.L. Wang, X.Y. Wang, J.Y. Li, J.M. Qin, M.L. Zhang, and Y.S. Lin. 2007. High-resolution climate variability of southwest China during 57-70 ka reflected in a stalagmite d18O record from Xinya Cave. Science in China Series D: Earth Sciences, Vol. 50, no. 8, pp. 1202-1208, August 2007. doi: 10.1007/s11430-007-0059-z. START YEAR: 69550 cal yr BP * END YEAR: 57620 cal yr BP 109.4667 30.75 109.4667 30.75