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Atmospheric 14C/12C changes during the last glacial period from Hulu Cave.

Authors :
Cheng, Hai
Edwards, R. Lawrence
Southon, John
Matsumoto, Katsumi
Feinberg, Joshua M.
Sinha, Ashish
Zhou, Weijian
Li, Hanying
Li, Xianglei
Xu, Yao
Chen, Shitao
Tan, Ming
Wang, Quan
Wang, Yongjin
Ning, Youfeng
Source :
Science. 12/14/2018, Vol. 362 Issue 6420, p1293-1297. 5p. 4 Graphs.
Publication Year :
2018

Abstract

Paired measurements of 14C/12C and 230Th ages from two Hulu Cave stalagmites complete a precise record of atmospheric 14C covering the full range of the 14C dating method (~54,000 years). Over the last glacial period, atmospheric 14C/12C ranges from values similar to modern values to values 1.70 times higher (42,000 to 39,000 years ago). The latter correspond to 14C ages 5200 years less than calibrated ages and correlate with the Laschamp geomagnetic excursion followed by Heinrich Stadial 4. Millennial-scale variations are largely attributable to Earth’s magnetic field changes and in part to climate-related changes in the oceanic carbon cycle. A progressive shift to lower 14C/12C values between 25,000 and 11,000 years ago is likely related, in part, to progressively increasing ocean ventilation rates [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00368075
Volume :
362
Issue :
6420
Database :
Academic Search Index
Journal :
Science
Publication Type :
Academic Journal
Accession number :
133612450
Full Text :
https://doi.org/10.1126/science.aau0747