40Ar-39Ar age of carbonatite-alkaline magmatism in Sung Valley, Maghalaya, India

Journal of Earth system science

Jyotiranjan S Ray1 2¹  Kanchan Pande1¹ 

[1] Physical Research Laboratory, Navrangpura, Ahmedabad 380 009, India.$$

关键词: 40Ar-39Ar dating;    carbonatite;    Sung Valley;    Rajmahal Traps;    Kerguelen plume.;   

DOI  :  

学科分类：天文学(综合)

来源: Indian Academy of Sciences

【 摘 要 】

40Ar-39Ar analyses of one alkali pyroxenite whole rock and two phlogopite separates of calcite carbonatites from the Sung Valley carbonatite-alkaline complex, which is believed to be a part of the Rajmahal-Bengal-Sylhet (RBS) ood basalt province, yielded indistinguishable plateau ages of 108.8 ± 2.0 Ma, 106:4 ± 1.3 Ma and 107.5 ± 1.4 Ma, respectively. The weighted mean of these ages, 107.2 ± 0.8 Ma, is the time of emplacement of this complex. This implies that Sung Valley complex and probably other such complexes in the Assam-Meghalaya Plateau postdate the main ood basalt event (i.e., the eruption of tholeiites) in the RBS province by ∼10 Ma.

【 授权许可】

Unknown