Reconsideration of Some Problems in the Archaean Complex of Mysore

The stratigraphy and age relationships of certain rock formations of Mysore are reviewed and the following points made out. (1) The Peninsular Gneisses as a whole are not intrusive into Dharwars. (2) The existing three fold classification of Dharwars has not taken into consideration the Dharwarian succession in Goa and north Mysore and requires to be revised. The Dharwar sediments were deposited in a narrow geosynclinal trough and did not extend very much beyond their present limits. (3) The name Champion Gneiss should be used only as a local name to designate the micaceous gneisses bordering the Kolar schists and not extended to other formations. (4) The charnockite terrain represents the lower most section of the Archaeans. The Dharwars occupy stratigraphically a higher position than the deep seated charnockites. (5) Basic dykes cutting across the gneisses and schists are pre Cuddapah in age. (6) The term Dharwar should be restricted only as a local name to the schistose rocks of Mysore. The crystalline schists of other regions may represent only a portion of Dharwar or be entirely different.