TY - JOUR
T1 - Uplift-driven climate change at 12 Ma
T2 - A long δ18O record from the NE margin of the Tibetan plateau
AU - Dettman, David L.
AU - Fang, Xiaomin
AU - Garzione, Carmala N.
AU - Li, Jijun
N1 - Funding Information:
The authors thank Dr. Song Chunhui and Fan Majie for field assistance. Financial support was provided to D.L.D. by the National Science Foundation (EAR9510033 and EAR9905887). X.F. thanks the CAS ‘Hundred Talents Project’, the MOE Key Project on Sci-Technology Research and the Chinese National Key Projects for Basic Research on Tibet Plateau (G1998040809) for financial support. [SK]
PY - 2003/9/10
Y1 - 2003/9/10
N2 - Carbonates from fluvial and lacustrine sediments were sampled from multiple measured sections in the Linxia basin of western China. Based on textural and mineralogical evidence, lacustrine carbonates are primary precipitates from lake water. A 29 million year record of the oxygen isotope composition of meteoric water is inferred from the δ18O values of these carbonates. This inference is based on the most negative δ18O values in the lake carbonates, which represent lake waters that have experienced the least evaporative enrichment. Carbonate δ18O values, a proxy for rainfall δ18O, are ∼-10.5‰ throughout the interval of 29-12 Ma. At 12 Ma there is a shift to -9‰, a value that remains into the Pliocene. This implies a major reorganization of atmospheric circulation patterns and a shift to more arid conditions at the NE margin of the Tibetan plateau with the post-12 Ma system similar to that of today. The 12 Ma event may represent the time at which the Tibetan plateau achieves sufficient elevation to block the penetration of moisture from the Indian Ocean or south Pacific into western China. The period of greatest aridity is from 9.6 to 8.2 Ma, a time interval which agrees well with other climate records.
AB - Carbonates from fluvial and lacustrine sediments were sampled from multiple measured sections in the Linxia basin of western China. Based on textural and mineralogical evidence, lacustrine carbonates are primary precipitates from lake water. A 29 million year record of the oxygen isotope composition of meteoric water is inferred from the δ18O values of these carbonates. This inference is based on the most negative δ18O values in the lake carbonates, which represent lake waters that have experienced the least evaporative enrichment. Carbonate δ18O values, a proxy for rainfall δ18O, are ∼-10.5‰ throughout the interval of 29-12 Ma. At 12 Ma there is a shift to -9‰, a value that remains into the Pliocene. This implies a major reorganization of atmospheric circulation patterns and a shift to more arid conditions at the NE margin of the Tibetan plateau with the post-12 Ma system similar to that of today. The 12 Ma event may represent the time at which the Tibetan plateau achieves sufficient elevation to block the penetration of moisture from the Indian Ocean or south Pacific into western China. The period of greatest aridity is from 9.6 to 8.2 Ma, a time interval which agrees well with other climate records.
KW - Lacustrine
KW - Miocene
KW - Oxygen isotopes
KW - Tibetan plateau
KW - Uplift
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U2 - 10.1016/S0012-821X(03)00383-2
DO - 10.1016/S0012-821X(03)00383-2
M3 - Article
AN - SCOPUS:0141595324
VL - 214
SP - 267
EP - 277
JO - Earth and Planetary Sciences Letters
JF - Earth and Planetary Sciences Letters
SN - 0012-821X
IS - 1-2
ER -