Geochemistry of rare metal bearing a-type dhanota granite, mahendragarh district, haryana

摘要

The Proterozoic Dhanota granite has intruded the Delhi Supergroup in the North Delhi Fold Belt (NDFB). Geochemically, it is a silica-rich, weakly paraluminous, sodic granite, enriched in high field strength elements (Zr, Nb, Y, Th) and Ga, with higher Ga/Al, Th/U and lower Ba/Rb ratios. The mineralogical and geochemical characters indicate the Dhanota granite as A-type, emplaced in an extensionalon-compressive tectonic regime around 665 degrees C at pressure of 5 kb. The anorogenic nature of the Dhanota granite distinguishes it from the other syn-orogenic, S-type granitoid bodies emplaced in the NDFB. Uranium-thorium-REE mineralization as uranothorite and xenotime is recorded in the Dhanota granite. This, together with its occurrence in proximity to the U-mineralized albitite line, and enrichment of HFS elements necessitate exploration for radioactive, rare metal and rare earth minerals in the area.