Geology and Genesis of Barite Deposits of Lasbela and Khuzdar Districts, Balochistan, Pakistan

Abstract: Geology and genesis of the sediment‐hosted barite deposits in the Lasbela and Khuzdar districts of Balochistan, Pakistan have been studied and described. Hot solutions generated in rifting environments during the initial stage of separation of the continental crustal block related to the Gondwanaland fragmentation subsequently reposed in Jurassic rocks, most probably played an important role on barite formation. Paragenetic relationships indicate that the period of barite mineralization was distinctly later than that of zinc‐lead sulphide mineralization in the Lasbela and Khuzdar districts. The barite deposits occur on top and in peripheral to the zinc‐lead sulphides. The earliest barite mineralization took place in the clastic rock sequence of the lower Spingwar Formation as cross cutting veins. Younger mineralization as stratabound‐replacement type occurred within the platform limestones of Loralai Formation, just above the Spingwar Formation. The youngest mineralization as stratiform is hosted within black shales, mudstones and argillaceous limestones of Anjira Formation at the top of Loralai Formation. In the light of the evidences gathered from field and laboratory investigations a genetic model has been deduced.