Siwalik sedimentation in a part of the Kumaun Himalaya,India

The Siwalik Group in a part of the Kumaun Himalaya has been studied with respect to its sedimentologic properties. Size-based environmental data indicate a fluviatile environment for the Middle and Upper Siwalik sediments. The Lower Siwalik samples indicate a border-line environment, possibly a fluvial-deltaic complex. Petrologically, the Siwalik samples are essentially sublitharenites and litharenites. Variation in petrological character in successive Siwalik units is not very marked, although the heavy-mineral assemblages serve the purpose of stratigraphic identification.Sedimentary structures, though not profuse, show a well-developed cyclic development corresponding to the idealised fining-upward sequence of alluvial sediments. They indicate deposition by laterally shifting braided streams. A major portion of the Siwalik detritus may be considered to have its provenance in the Himalayan metamorphic areas.