Depositional History of Damuda Sandstone in Lish-Ramthi Valley, Darjeeling District

Diagenetic changes and depositional history of the Damuda sandstone of a part of DarjeeJing Himalaya is described. The sandstones are classified as quartzitic and non-quartzitic on the basis of their physical characters. The quartzitic sandstones occur along the entire length of Precambrian Daling metamorphics as a thin zone whereas the non-quartzitic sandstones occupy the major part of the field.

The characters exhibited by the non-quartzitic sandstones indicate diagenetic conditions but in case of quartzitic sandstones it cannot be said with certainty. Possibly dynamic metamorphism caused by Daling thrust has had a role in bringing about the changes.