Geochemistry of Ukhrul limestone of Assam-Arakan subduction basin, Manipur, Northeast India

Abstract

Geochemical studies of the carbonate rocks of Ukhrul limestone from Hundung and Payoi area of Ukhrul District of Manipur, India have been carried out through investigation of major oxides and trace elements geochemistry to determine their chemical composition, to establish the distribution pattern and mutual relationship of the elements, for chemical classification of the limestones and also to decipher environmental conditions that existed during the time of deposition of the calcareous sediments. The study indicates that the limestones were deposited in open to protected near shore, marginal neritic environment with argillaceous sediment flux derived from a granitic continental crust. Protected basin existed partly in Paoyi area. Presence of marine gastropods and foraminifera fossils and higher concentration of strontium in the studied carbonate rocks suggest relatively shallow marine environment of deposition during the Eocene sedimentation.