Arsikere Granite-Its Petrography and Mode of Emplacement

Arsikere granite, with its porphyritic and aplitic phases, shows sharp contact with the surrounding gneisses but is concordant with its trend (NNW-SSE) only slightly deviating (NW-SE) from the gneisses. Marginal inclusions of gneiss, amphibolite and folded quartzsericite schist occur. Mineralogically, though similar to the enclosing gneiss, the granite consists of two generations of quartz and felspar. Chemically the granite is more acidic than the gneiss indicating an influx of SiO₂ and alkalies. The study of the Arsikere granite massif indicates that it is formed in situ, from the pre-existing rock which in the area is the gneiss of the Peninsular gneissic complex, through mobilisation.