Abstract
The Dzhulfian vidrioceratid ammonoid Stacheoceras trimurti DIENER was found associated with the brachiopod Elivina tibetana (DIENER) in the Kuling Formation in the northwestern Himalayas in Himachal Pradesh province, India. It was recovered from a horizon of dark weathering phosphatic limestone nodules 2 m below the Permian Triassic boundary in the Lingti River valley near Chumik Marpo. The Triassic ammonoid Ophiceras sp. indet. was found a few metres above the base of the overlying Tamba Kurkur Formation, the transgressive base of which is correlated with the Otoceras bed of the Spiti area. The Permian-Triassic boundary is marked by a distinctive 10 cm thick red-weathering, iron oxide-rich layer at the top of the Kuling Formation. For this part of the Gondwana shelf, this horizon suggests erosion accompanied by weathering during latest Permian time (Dorashamian).
Bucher, Hugo