Mantle source characterization of Sylhet Traps, northeastern India: A petrological and geochemical study

Journal of Earth system science

Daniel Meshesha1 3¹  Ryuichi Shinjo1¹  Md Shofiqul Islam1 2¹ 

[1] HIMU-like mantle component,$$

关键词: Sylhet Traps;    Shillong Plateau;    Kerguelen;    mantle plume.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

In this study, mineralogical, geochemical, and isotopic data are presented for the Sylhet Trap at the southern flank of the eastern Shillong Plateau, northeastern India, to determine the magma genesis in relation to the Kerguelen plume mantle source. Sylhet Trap rocks are porphyritic tholeiite and have diverse chemical compositions from picro-basalt, basalt, andesite to dacite, but mostly are within the subalkaline field. Major and trace element data were used to identify two distinct magma fractionation trends, a low and medium K series, characterized by relatively flat MORB-like (analogous to Rajmahal Traps (II)) and enriched OIB chondrite-normalized Rare Earth Element (REE) patterns. Initial 87Sr/86Sr, 143Nd/144Nd, and 206Pb/204Pb isotope compositions were widely varied, ranging from 0.70435–0.71357, 0.51196–0.51266, and 17.92–19.72, respectively, when compared with basalts from the West Bengal, the Rajmahal Traps and the Kerguelen plume. Correlations among isotopic and trace element ratios of the Sylhet Traps provide evidence for the involvement ofHIMU-like mantle component,

【 授权许可】

Unknown