Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

L. Gopeshwor Singh ¹, G. Vallinayagam ²

Affiliations
1 Department of Geology, Kurukshetra University, Kurukshetra-136119, IN
2 Department of Geology, Kurukshetra University, Kurukshetra -136119, IN

Abstract

Occurrences of large multi-shell orbicular structures m Malani Igneous Suite, Western Rajasthan has been reported for the first time The orbicules occur in an Anorogenic, A-type rhyolite The majority of the orbs comprise of a senes of distinct shells (layers) viz dark and light colour shells surrounding a core The shells consist of orthoclase, sanidme, quartz (light colour shell) and orthoclase, iron oxide (magnetite& ilmenite), riebeckite and arfvedsonite (dark colour shell) The core and groundmass of the orbicules have identical composition.

Keywords

Orbicular Structure, A-type Rhyolite, Malani Igneous Suite, Dhiran Barmer, Rajasthan.

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