Interaction between felsic granitoids and mafic dykes in Bundelkhand Craton: A field, petrographic and crystal size distribution study

Abstract

In Bundelkhand Craton of central India, mafic dykes intruded when granitoids was partly crystallized. Cuspate-lobate boundary along the contact of granitoids and mafic magma indicates magma mingling in outcrop scale while textural evidence of mingling is represented by acicular apatite morphologies, titaniteplagioclase ocelli and ophitic-subophitic texture, mafic clots, resorbed plagioclase, and hornblende-zircon associations. Mingling also caused thermal exchange and fluid activity along the boundary between two coeval magmas. Crystal size distribution analyses for hornblende in the mafic rocks yield concave up curves which is also consistent with interaction of felsic and mafic magmas.

Evolution of Bundelkhand Craton

“…Presence of plagioclase crystals across the contact boundary is one of the most common evidence of mixing reported by Ramiz and Mondal (2017). Deb and Bhattacharya (2018) suggested that chemical analysis should also be supported by meso-and microscale textural evidences to confirm the signature of magma mixing. They reported acicular apatite, titanite-plagioclase ocelli, ophiticsubophitic texture, mafic clots, resorbed plagioclase, hornblendezircon asscociation and cuspate-lobate boundary along the contact of granitoid and mafic magma which confirm the magmatic mixing in the BuC.…”