ABSTRACT: The palynostratigraphy and organic geochemistry of the Shinawari Formation exposed in the Surghar Range is used to investigate the occurrence of the Toarcian Oceanic Anoxic Event in Pakistan. The Shinawari Formation is composed of limestone, marls, sandstone, organic rich shale, coal patches, siltstone, and mudstones. The black shales in the lower-middle part has preserved a high abundance of the flora including one hundred different species of pollen, spores and acritarchs. The identified palynomorphs correspond to two assemblage biozones; the Callialasporites turbatus assemblage biozone (CTUABZ I) of Toarcian-Bajocian age and the Callialasporites trilobatus assemblage biozone (CTLABZ II) of early Bajocian-middle Bathonian age. The isotope stratigraphy of the Toarcian-Bathonian strata revealed a large amplitude negative excursion of 5‰in the bulk organic matter, and a similar trend in the d13C of the bulk carbonate. The isotope data correlatedwith the age constraints from the palynostratigraphic zonation indicates the occurrence of the Toarcian Oceanic Anoxic Event in the study area.

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