Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

A. C. Banerjee ¹, Des Raj ¹, Manas Roychowdhury ²

Affiliations
1 Geological Survey of India, Sector 10A, Gandhinagar - 382 043, IN
2 Coal Wing, Geological Survey of India, 29, J. N. Road, Calcutta - 700 016, IN

Abstract

Some samples from a chrome spinel-bearing intrusive picrite within olivine rich Deccan basalts at Limbdi in Saurashtra show anomalous high contents of gold (148-231 ppb), platinum (15-125 ppb) and palladium (17-311 ppb). Other samples bear an avenge of ∼6 ppb of gold, ∼31 ppb of platinum and ∼42 ppb of palladium. Sulphide mineralisation in the picrite is of extremely fine grain size, with low to moderate whole-rock contents of sulphur varying between 0.08 to 0.53 %. Higher values of gold and platinum are found in the western olivine-rich portion of the intrusive, while at surface level platinum/palladium ratio decreases due east with increase in palladium. This intrusive with higher average contents of precious metals could be a potentid target for exploration. Such high contents of gold, platinum and palladium are hitherto unreported from Deccan volcanic province.

Keywords

Gold, Platinum, Palladium, Economic Geology, Picrite, Deccan Trap, Saurashtra, Gujarat.

Full Text

     

K. C. Prashra ¹, Des Raj ¹

Affiliations
1 Geological Survey of India, SCO 98-99-100, Sector 17-C, Chandigarh 160 017, IN

Abstract

The reported fossil assemblage, when integrated together with earlier known fossils, indicates an age range of Permian to middle Jurassic for the Tandi Group. The deposition of the Tandi Group over the Precambrian rocks represents a major Permian (Djulfian) transgression in the area from Kashmir-Bhallesh-Charnba region, whereafter deposition in the area continued till Jurassic.

Keywords

Permo-Triassic, Tandi Group, Lahaul Himalaya, Palaeogeography, Palaeontology.

Full Text