Orbicular Rhyolite of Dhiran Area, Malani Igneous Suite, Barmer District, Western Rajasthan

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.