Chukh Gr

Upward succession of Dangardzong Fm, Kagbeni Fm, and Dzong Fm. "Lower Cretaceous terrigenous rocks have long been described in detail (e.g. Bordet et al., 1967, 1971) but, owing to complex fold-thrust deformation, ambiguities and mistakes as to internal stratigraphy abound in the geologic literature. The name Chukh formation was first introduced by Bodenhausen et al. (1964) to designate a dark green sandstone and siltstone unit with plant remains, bearing "uncertain relation with under-lying units'". The Chukh Fm. was in fact wrongly held by these Authors to overlie their ``Checkpost formation'' (which in the type area to the north of Jomosom represents in fact a faulted slice of Zhamure Sandstone Fm [= Thini Fm] and to underlie their ``Shaligram formation'' (correlatable with the Spiti Shale [Spiti Fm]. … Bassoullet and Mouterde (1977) adopted the name Chukh Formation and subdivided it into two members: the Kagbeni Sandstone below (grês continentaux of Bordet et al., 1967, 1971) and the Dzong Sandstone above (grès verts of Bordet et al., 1967, 1971). The Chukh Formation, showing a number of differences in age and lithology with respect to the Giumal Sandstone Fm of the Spiti-Zanskar Synclinorium (Stoliczka, 1866; Garzanti, 1991a, 1993b), was finally elevated to group rank by Gradstein et al. (1989, 1992)."

Synonym: Tangbe Fm ("Gibling et al., 1994; Dürr and Gibling, 1994; Nagy et al., 1995) chose to dismiss the term Chukh Group and proposed instead to group the Kagbeni Fm and Dzong Fm under the name Tangbe Formaton,")

Quartzite (Dangardzong Fm), coarse volcaniclastics (Kagbeni Fm), marl (Dzong Fm).