Modal data-based simple statistical analysis as an effective petrogenetic indicator: a study from Kadavur gabbro-anorthosite complex, Tamil Nadu, southern India

Field and petrographic studies on the Neoproterozoic Kadavur intrusive complex (10°35¢N, 78°11¢E) (located in the Southern Granulite Terrane of the Indian shield) reveal three distinct types: (i) earliest phase of deformed schistose gabbro-anorthosite; (ii) most dominant laye­red gabbro-anorthosite, and (iii) locally developed pegmatoidal gabbro-anorthosite. A simple modal data-based statistical analysis of layered gabbro-anorthosite type yields highly significant or significant correlation coefficients for different mineralogical parameters and strongly supports differentiation from a common magma. Typical dispositions of the mineralogical parameters (as depicted by isopleths patterns) suggest maintenance of a magmatic lineage in varying hydration ambience that developed several petrographic variants within the layered type