Thermal Alteration History of the Fenghuoshan Group, Hoh Xil Basin, Northern Tibetan Plateau: Insights From Clumped Isotope Thermometry

Kong，Kai1,2,3,4; Deng，Wenfeng1,2,3; Guo，Yangrui1,2,3; Jin，Chunsheng5; Liu，Qingsong6; Wei，Gangjian1,2,3

2021-10-01

10.1029/2021JB022009

JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH   影响因子和分区

2169-9313

2169-9356

The carbonate clumped isotope (Δ) thermometer has been widely used for paleoclimatic and paleo-elevation reconstructions in sedimentary basins. Its reliable use requires that carbonates are free from later diagenetic alteration and retain their depositional Δ compositions, which is not always the case during the burial history of a basin. Therefore, identifying the alteration mechanisms that occurred during burial is essential for the correct interpretation of Δ signatures. In this study, we used the Δ thermometer to investigate possible carbonate alteration during burial of the Fenghuoshan Group (FHSG) in the Hoh Xil Basin, northern Tibetan Plateau, China. The Δ temperatures [T(Δ)] of 30 carbonate samples through the ∼4.5 km thickness of the FHSG range from 51 to 132°C and exceed the surface temperature, implying the effects of thermal alteration on FHSG carbonates. The T(Δ) values combined with the water-rock exchange model, indicating that the alteration occurred under closed burial conditions at low water:rock ratios. The solid-state reordering model fails to predict the Δ values, even with a modified time-temperature history. In contrast, most measured Δ values are in agreement with predictions from recrystallization models. Therefore, the proposed alteration scenario is that FHSG carbonates underwent progressive microscale recrystallization during deep burial and subsequent exhumation, during which process recrystallized carbonate equilibrated with ambient burial temperature and therefore modified Δ values. This study highlights the potential of Δ thermometry and related models for evaluating the burial history and diagenesis of carbonates in sedimentary basins.

clumped isotopes diagenetic alteration Fenghuoshan Group Hoh Xil Basin solid-state reordering

SCI

英语

其他

WOS:000711968800032

GEOSCIENCES

2-s2.0-85118221005

Scopus

1.State Key Laboratory of Isotope Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou,China
2.CAS Center for Excellence in Deep Earth Science,Guangzhou,China
3.Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou),Guangzhou,China
4.College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing,China
5.Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing,China
6.Department of Ocean Science and Engineering,Southern University of Science and Technology,Shenzhen,China

Kong，Kai,Deng，Wenfeng,Guo，Yangrui,et al. Thermal Alteration History of the Fenghuoshan Group, Hoh Xil Basin, Northern Tibetan Plateau: Insights From Clumped Isotope Thermometry[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2021,126(10).

Kong，Kai,Deng，Wenfeng,Guo，Yangrui,Jin，Chunsheng,Liu，Qingsong,&Wei，Gangjian.(2021).Thermal Alteration History of the Fenghuoshan Group, Hoh Xil Basin, Northern Tibetan Plateau: Insights From Clumped Isotope Thermometry.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,126(10).

Kong，Kai,et al."Thermal Alteration History of the Fenghuoshan Group, Hoh Xil Basin, Northern Tibetan Plateau: Insights From Clumped Isotope Thermometry".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 126.10(2021).