Conodont biostratigraphy of the Lower Triassic in Spiti Himalaya, India

Early Triassic sequence of about 30 m thickness is exposed at Lalung (Lilan g) in Spiti, Himachal Pradesh. The sequence, traditionally defined by the O toceras bed at the base and the Keyserlingites bed at the top, is biostrati graphically defined in this paper by eight successive conodont zones, which in the ascending order are: Neogondolella orientalis - N. subcarinata Asse mblage Zone, Neospathodus kummeli Zone, Neospathodus dieneri Zone, Neospath odus cristagalli Zone, Neospathodus pakistanensis-Neogondolella nepalensis Assemblage Zone, Neospathodus waageni Zone, Neogondolella elongata Zone and Neospathodus timorensis Zone. These conodont zones are delineated on the b asis of data from Lalung, Mud (Muth), Guling (Kuling) and Spiti River secti ons in the Spiti valley.