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

Research on the Fenghuoshan Group in Qinghai Hoh Xil reveals that carbonates underwent significant thermal alteration during deep burial and exhumation, potentially skewing paleoclimatic reconstructions. Clumped isotope thermometry (Δ47) analysis of 30 carbonate samples from the ∼4.5 km-thick group showed temperatures ranging from 51 to 132°C—well above surface conditions—suggesting burial-related recrystallization rather than solid-state reordering. The study proposes that carbonates equilibrated with ambient burial temperatures during progressive microscale recrystallization, modifying their Δ47 signatures. This finding underscores the need for careful diagenetic assessment when using clumped isotopes for paleoclimatic or paleo-elevation studies in sedimentary basins.

Kong, K., Deng, W., Guo, Y., Jin, C., Liu, Q., & Wei, G. (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). Portico. https://doi.org/10.1029/2021jb022009