The Gold Content of Deccan Basalts Western Ghats, India

Sixty nine (69) samples of Deccan basalt flows from the Western Ghats representing the Wai, Lonavala and Kalsubai subgroups average 3.7 ppb of gold. Gold content shows limited variation from 3.0 to 5.8 ppb in 62 samples whereas they range from 1.4 to 2.7 ppb in 7 samples. Flows of the Wai subgroup show the maximum variation in gold abundances (1.4 - 5.8 ppb) and which may be related to the presence of primitive uncontaminated basalts (Ambenali)- lowest value-crust-contaminated basalts (Poladpur) and basalts derived from enriched-mantle sources (Mahabaleshwar). Gold appears to be insensitive to crystal fractionation or differentiation as basalts of different types such as the picritic, porphyritic, aphyric and giant plagioclase-bearing types found within a subgroup or formation have similar avcrages (3.6-3.8 ppb).

Deccan Tholciitic basalts contain higher amounts of gold than dome of the occean island (Hawaii) tholciitic basalts island are (Kurile-Kamchatka) tholciites, but contain values similar to those found in the Columbia River basalt province.