6. Discussion
6.1. Modal compositions and provenance
Previous studies have proposed that the Barail Group sandstones
were derived from a quartzose recycled orogen (Johnson and Alam,
1991; Uddin and Lundberg, 1998); whereas the Surma Group
sandstones were sourced from a mixed, transitional continental and
quartzose recycled source terrain (Johnson and Alam, 1991).Uddin and
Lundberg (1998)suggested that Barail sandstones were derived from
proto-Himalayan sources, and that Surma sandstones originated from granitic sources in the High Himalayan Crystalline terrane.Najman and
Garzanti (2000)favoured derivation of both the Barail and Surma
Groups from early Himalayan thrust sheets