Harutaka Sakai

Department of Geology, Kyushu University

Fukuoka, 812 Japan

In the Tansen area of Lesser Himalayas in western Nepal we can distinguish a sedimentary terrace which corresponds to the Krol Belt of the Kumaon Lesser Himalayas. The terrace lies north of the Main Boundary Thrust, and includes the Lower Gondwana glacial beds (the Sisne Formation), the Upper Gondwana beds (the Taltung), the probably Cretaceous beds containing marine facies (the Amile), the middle Eocene beds (the Bhainskati), and the possible Oligocene to early Miocene beds (the Dumri) consisting of thick, nonmarine sandstones. The first can be correlated with the Blaini of the Simla-Kumaon Krol Belt, the second and the third with the Tal, the fourth with the Subathu and the last with the Dagshai. However, no rock units that are lithologically and stratigraphically comparable with the Infra Krol and the Krol are present in the Tansen area. On the other hand, the Taltung Formation is unique in containing the Upper Gondwana Flora and basaltic lava flows, both of which have not been recognized elsewhere in the Lesser Himalayan Range.

The rock units that were formerly assigned to the Blaini, the Infra Krol and the Krol in the Tansen area are comparable with the sequence ranging from the Deoban (Ganglihat) Limestone, through the Sor Slates, to the Talkedar Limestone of the Tejam Group in the Krol Belt of Kumaon.