Numerical analysis as applied to the environmental interpretation of carbonate microfacies of some sub-Himalayan carbonates (lower upper precambrian) in northwestern India

Forty-three samples of (1) Sirban Limestone of Riasi, Jammu and Kashmir State, India, based on six mineralogic and petrographic presence-absence variables, and (2) 36 samples of Bilaspur Limestone based on 11 presence-absence mineralogic and petrographic variables, were numerically classified by Q-mode cluster analysis using Sokal and Michner's Simple Matching Coefficient. Sirban Limestone of Riasi yielded 10 clusters or groups indicating four depositional environments: (1) intertidal, (2) intertidal to subtidal, (3) subtidal, and (4) deep-water basinal. Similarly, Bilaspur Limestone yielded nine clusters indicative of the same four environments. A Q-mode ordination of the Riasi samples and of Bilaspur Limestone shows a generalized shelf-to-basin carbonate deposition profile. Results of this study substantiate earlier conclusions of Rao (1979) based on field, mineralogic, and petrographic study of the above-mentioned carbonates.