A new find of calc-alkaline lamprophyres in Thanewasna area, Western Bastar Craton, India

• DOI: 10.1007/s12040-018-1037-x
• Publication Date: 2018-11-16T20:42:10Z
• Authors: R R Meshram; M L Dora; R Naik; M Shareef; G Gopalakrishna; T Meshram; S R Baswani; K R Randive
• Keywords: Porphyritic; Amphibole; Phenocryst; Hornblende; Pyroxene

Lamprophyre dykes within the granitoid and charnockite are reported for the first time from the Western Bastar Craton, Chandrapur district, Maharashtra. It shows porphyritic–panidiomorphic texture under a microscope, characterised by the predominance of biotite phenocrysts with less abundance of amphibole and clinopyroxene microphenocryst. The groundmass is composed more of K-feldspars over plagioclase, amphiboles, clinopyroxene, biotite, chlorite, apatite, sphene and magnetite. The mineral chemistry of biotite and magnesio-hornblende is indicative of minette variety of calc-alkaline lamprophyre (CAL), which is further supported by preliminary major oxides and trace element geochemistry. This unique association of CAL with granitoid provides an opportunity to study the spatio-temporal evolution of the lamprophyric magma in relation to the geodynamic perspective of the Bastar Craton.