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Tarim Large Igneous Province Caused by a Wide and Wet Mantle Plume
Author(s) -
Liu Hao,
Leng Wei
Publication year - 2020
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1029/2019jb019001
Subject(s) - geology , mantle plume , plume , flood basalt , mantle (geology) , large igneous province , lithosphere , igneous rock , volcano , basalt , geochemistry , petrology , paleontology , tectonics , volcanism , magmatism , physics , thermodynamics
Large igneous provinces (LIPs) can form by interactions between a hot mantle plume and the lithosphere. The Tarim LIP between ~300 and 280 Ma, located in Northwest China, has been investigated by geochemistry and sedimentology studies. However, the factors controlling Tarim LIP formation and the ancient Tarim plume characteristics remain unclear. Here, a series of 3‐D geodynamic models are combined with geological observations to constrain the Tarim LIP evolution and the features of the related Tarim plume. Our results show that (1) an ancient plume produced abundant melts attributed to decompression melting, excess temperature, high water contents, and slow plate motion velocities to form the banded Tarim LIP. (2) The simulated pre‐eruption topography coincides with the stratigraphic records from the late Carboniferous to early Permian. Specifically, the swell area of pre‐eruption topography is sensitive only to the plume radius and enables us to constrain the ancient mantle plume size well. (3) Based on the volcanic activity and pre‐eruption topography, we infer that the ancient Tarim plume had a very large radius of ~200 km, a high excess temperature of ~250 K, and a high water content of ~5 wt.%. (4) Our parameter tests and global plate reconstruction results show that high water contents and slow plate motion velocities facilitate continental flood basalts to form with thick lithosphere. Our geodynamic modeling not only provides new constraints for the Tarim LIP evolution but also first quantificationally demonstrates that water in the mantle plays a key role in continental flood basalt formation.