Carbonatite-Alkaline Complex of Mundwara

Abstract

Two types of carbonatite dykes - alvikite and beforsite are associated with (the Mundwara alkaline igneous complex. Petrochemical and mineralogical studies indicate enrichment of alkalies and niobium. Pyrochlore is noted in beforsites along with dolomite, apatite, barite and flourite, whereas calcite, ankerite, heamatite, aegirine, apatite and barite are noted in the alvikites. The presence of both metasomatic as well as intrusive syenites are noticed. Higher content of Nb is noted in the syenites containing sphene, aegirine and magnetite.

The presence of annular fractures around the plutons and the arcuate shatter zone with breccia on the outer margins of the Mer pluton indicate upwarping and later intrusion of carbonatites through the Erinpura granite. High P₂O₅ and Nb content of the soil samples around Mer Pluton suggest possible existence of a carbonatite plug below.