Glimmeritic enclave in a lamprophyre from the Settupalle alkaline pluton, Eastern Ghats mobile belt

摘要: A rare occurrence of glimmeritic (mica-rich) enclave — composed abundant modal biotite, subordinate proportions clinopyroxene and apatite, minor amounts feldspar, carbonate sphene is reported from the lamprophyre Settupalle alkaline pluton, Eastern Ghats mobile belt (EGMB), India. The displays very coarse grained equigranular texture (mica laths up to 5 mm grains 4 mm). In comparison, host exhibits a marked porphyritic-panidiomorphic comprising phenocrysts clinopyroxene; other phases such as biotite potash- plagioclase-feldspar are restricted groundmass. tight closeness in mineral chemistry glimmerite imply possible genetic relationship between their parent magmas. Glimmeritic construed be an autolith proto-lamprophyre magma, which failed reach surface, lined wall-rock along conduit lamprophyric intrusion. Glimmerite provides direct evidence for multi-stage modification lithospheric mantle due infiltration potassium-rich hydrous melts lamprophyres. Mineralogy also similar that vein component hydrous, mafic potassic-ultrapotassic veined lithosphere EGMB.