Trilochan Singh

Brachiopoda from the Early Permian of the Eastern Himalaya

Early Permian brachiopods are described from the Garu Formation of the eastern Himalaya. New species are Tivertonia tatamariensis, Costatumulus sahnii, Tomiopsis siangensis and Trigonotreta orientensis. The age of the fauna is reviewed with an early Sterlitamakian (Sakmarian) age being preferred.

Sandstone dykes in siwalik sandstone-sedimentology and basin analysis-subansiri district (NEFA), Eastern Himalaya

Abstract Sandstone dykes (including sills) of varied thickness and with tapering ends are present either transecting or (sills) parallel to bedding in the Siwalik sandstone of Arunachal Pradesh (NEFA), Eastern Himalaya. The different sedimentary and microstructural analyses show varied conditions of deposition with changing facies from fluvial channel, to alluvial fan, to coastal plain-fan delta. The non-marine and shallow marine environments are indicated by the presence of organised and disorganised gradation and the presence of sandstone dykes in the interface regions. The orientations of the longer axes of the conglomerate along with the sand bedding indicate palaeoflow.

Early Permian Foraminifera from Eastern Himalaya and their palaeobiogeographic significance

Foraminiferal assemblage from Permian rocks of Eastern Himalaya, India are recorded for the first time. Twenty-two genera and twenty-eight species are documented from the Garu Formation, Eastern Himalaya. The foraminiferal assemblage supports previous age determinations based on megafauna. The distinctive foraminiferal assemblage from India supports the recognition of Australian and Afghanistan-Indian provinces in the Early Permian Austral realm. An appreciable number of common species in these provinces is indicative of close geographic links.

Occurrence of faunal coal balls in Gondwana sediments (Permian) of Arunachal Himalaya, India

Abstract The nature and genesis of fossiliferous inorganic concretions present within the coal and carbonaceous beds of Garu Formation, Arunachal Pradesh have been studied in detail. These concretionary bodies are described here as “coal balls” due to their close similarity with the true coal balls reported from European and American coals. Further, the presence of coal balls in this area also indicates that the sediments of the Garu Formation were deposited in shallow marginal swamps subjected to marine incursions during the Lower Permian.