Temporal distribution of selected elements in carbonate rocks of Middle Jurassic Jaisalmer formation, Rajasthan, India

Abstract

The distribution and vertical variation patterns of Ca, Mg, Fe, Mn, Sr, K, Na, Pb, Zn, Ni and IR (Insoluble Residue) from carbonate rocks of Jaisalmer Formation suggest a change in the depositional conditions of the basin through time from a normal marine to hypersaline depositional environment. The R-mode factor analysis of the chemical data reveal the significance of three common factors contributing about 72 percent of total variance. These three factors have been interpreted as related to gross mineralogy, colloidal precipitation of secondary minerals and the effect of diagenesis. Based on the present study, a shallow, near normal to less marine condition of the deposition has been interpreted for the lower four members (viz. Hamira, Joyan, Fort, and Badabag) and a hypersaline, lagoonal environment suggested for the topmost Kuldhar member of the Jaisalmer Formation.