Simla Group - A Reclassification of the 'Chail Series' 'Jaunsar Series' and 'Simla Slates' in the Simla Himalaya

The study of 'Chail Series', 'Jaunsar Series' and 'Simla Slates' in the Simla Himalaya has brought out the incongruities in the present lithostratigraphy of these formations. The Simla group, divisible into four formations, is the revised classification proposed. The Basantpur, with shale, siltstone and abundant limestone interbeds, is at the bottom of the Simla group sequence, and in the ascending order, succeeded by the Kunihar with shale and stromatolitic limestone, the Chhaosa containing flysch sediments and the Sanjauli with conglomerate and grit facies. The Simla group represents a typical geosynclinal cycle of sedimentation deposited over the Shali, Sundernagar and Mandi-Darla volcanic rocks.