Professor QIN Kezhang and his team investigate some of the Ni-Cu-bearing mafic-ultramafic intrusions in the Eastern Tianshan and Beishan Rift, and present zircon SIMS U-Pb age and Sr-Nd isotopic data as well as compiled results from previous studies, to understand the correlation between the Tarim flood basalts and maficultramafic intrusions, and to provide geochronological and isotopic constraints on the mantle plume.

The histogram of compiled age data of basalts in the Tarim Basin and mafic-ultramafic intrusions in the Eastern Tianshan and Beishan Rift has a peak of 280 Ma, which probably represents the time of mantle plume activity.

A possible mantle plume model beneath lithospheric mantle of the Tarim Basin, Tianshan and Beishan and its spatial framework is suggested.

Fig.1. (A) Geological map of the Tarim Basin (NW China) showing the minimum distribution of Early Permian basalts.(B) Geological map of the Eastern Tianshan and Beishan rift showing the distribution of Early Permian mafic-ultramafic complexes. (Image by QIN)

Fig.2. (A) Histogram of compiled age data (n _ 119) of magmatic and hydrothermal ore deposits in NWChina yielding a peak age between 280_300 Ma. (B) Histogram of compiled age data (n _ 71) of basalts and mafic/ultramafic dikes/intrusions in Tarim Basin, Eastern Tianshan and Beishan. (C) Compiled ages with errors showing a ca.280 Ma peak. (Image by QIN)

Qin et al. SIMS zircon U-Pb geochronology and Sr-Nd isotopes of Ni-Cu-bearing mafic-ultramafic intrusions in eastern Tianshan and Beishan in correlation with flood basalts in Tarim Basin (NW china): constraints on a ca. 280 Ma mantle plume. American Journal of Science, 2011, 311(3):237-260 （Download Here）