First Research on Marine and Nonmarine Sedimentary Sequences and Micropaleontologic Significance across Permian/Triassic Boundary in Iran (Isfahan and Abadeh)

Abundant ichthyoid remains, conodonts and holothurians sclerites were recovered near the Permian/Triassic boundary from a section south of Isfahan. Recovered ichthyoid remains include shark micro teeth and scales. The ichthyolith material is similar to a Fasanian ichthyolith from the Zakazane area in the Slovak karst of the Western Carpathians, which represents a subspecies of Acodina triassica. Conodont species are mostly neogondolellids. This fauna indicates that the sedimentary environment was marine, while to the north of localities near Isfahan and Zagross, terrestrial deposition was dominant at that time. Aluminasilicate and kaolin are present in a continental unit in Dopolan refractory main (Shahid Nilchian mine) and a section south of Chahriseh Village, north of Isfahan. Pisolitie, ironstone facies and bauxite clay are common near the Permian/Triassic boundary in the Chahriseh region.