Zewan Fm

[Original Publication: Pascoe, E.H. 1973. A Manual of Geology of India and Burma. Controller of Publications, Government of India, Delhi, 1-3.]

Sandstone and limestone. The Zewan Formation comprises calcareous sandstone, sandy limestone and shale. Nakazawa et al., (1975) divided it in four members.

Conodonts: Hindeodus minutus and Gondolella carinata. Bivalve: Aviculopecten cf. hiemalisBrachiopod: Productus cora, P. indicus, P. spiralis, P. gangeticus, P. abichi, Spirifer rajah, S. nitiensis, S. fasciger, Lamnimargus himalayansis, L. vihiana, Sperigera xeta S. derbyi, S. saucepans, Spiriferellina zewanensis, Dielasma biplex, D. acutangulum, D. hastatum, Camarophoria purdoni, Chonetes lissarensis, C. laevis, Speriferina cristata, Lyttonia nobilis; Bryozoa: Protoretepora ampla, Fenestella aff. fossula; Coral: Amplexus sp, Zaphrentis sp. Ammonoid: Cyclolobus walkeri, Member A encloses foraminifers, bryozoa, crinoid-stems and brachiopods. The characteristic fossils are: Colaniella cf. minima, C. cylinderica and Abadehella cf. coniformis. The fossil assemblage signifies Abadehian age.Member B is poor in fossils and shows remarkable decrease in foraminiferal and bryozoal contents.Members C and D are characterized by gastropods and bivalves and contain Cyclolobus walkeri, Hindeodus minutus and Gondolella carinata.

Nakazawa et al., (1975) and Brookfield et al., (2003) dealt with the environment of sedimentation for the Zewan Formation. Events across the Permian-Triassic in the Guryul section have been described by Algeo et al., (2007). Evidence for oxygen is equivocal in the Kashmir section. The upper Zewan Formation (bed 46) is bioturbated and was possibly deposited under well-oxygenated conditions. The uppermost 5 m of the Zewan Formation consists of graded and bioturbated layers and lamination typical of deposits of waning storms. Parts of the section show unidirectional slumping indicating appreciable slopes, possibly disturbed by earthquakes.