Abstract

The Permian-Triassic boundary in the Himalayas is reviewed and discussed in
the light of palaeontologic and stratigraphic data collected during the past two and a
half decades from Kashmir, Spiti and Nepal. The deposition of the Kuling Shales
and their equivalents in different parts of the Himalayas was followed by shallowing
and regression of the sea. Sedimentation was interrupted at the top of Kuling Shale
sequence resulting in the emergence of many areas. This was followed by
widespread and simultaneous marine transgression resulting in deposition of
Otoceras-bearing beds. Otoceras woodwardi Zone has been assigned to the
Griesbachian age. The base of Ophiceras tibeticum Zone corresponds to the
base of Isarcicella isarcica conodont zone; the disappearance of Otoceras, Permian
brachiopods and other holdovers. It is suggested that the base of Gyronites frequens
Zone is the most befitting for demarcating and documentation of the Perrnian-
Triassic boundary as this stratigraphic level corresponds to the end of the lowest
faunal diversification and coincides with the Griesbachian-Dienerian boundary. This
boundary is also marked by striking changes in conodont fauna from
Anchignathodus and Zsarcicella to Kashmirella and Neospathodus