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Abstract

The present study mainly focused on the microfacies based depositional environments of Upper Cretaceous Kawagarh Formation from Thoba and Chinali Sections exposed in northeastern Hazara Basin. A total of 325 samples of limestone were collected from above mentioned sections for petrographic studies. Calcispheres, planktons, inoceramids and filaments are recognised as dominant skeletal grains embedded in micritic matrix. Biota assemblages and their abundance are used to establish seven microfacies which include Calcisphere-Planktonic wackestone and packstone, Planktonic-Calcispher wackestone, Planktonic wackestone, Dolostone, Inoceramous-Planktonic wackestone, Planktonic-Filamentous wackestone and Filamentous-Planktonic wackestone microfacies. Absence of reef, extensive reworking and shallow deposition and carbonate sand shoal barriers suggest the deposition of Kawagarh Formation over the ramp setting. Paleoecology of main biota (calcispheres, planktons and filaments) and microscopic sedimentary structure recorded in microfacies reveal that Kawagarh Formation was deposited over mid and outer ramp settings as deepening upward sequence.