A Note on Incipient Spilitisation of Central Indian Basin Basalts

Rocks dredged in the vicinity of the 79°E fracture zone, in the Central Indian Basin, are sub-alkaline basalts, which are regarded as precursors to spilites. The Minerals identified are mainly albitic plagioclase, augite, olivine, and less of chlorite, epidote and opaques. The oxide variation plots indicate a mid-ocean ridge basalt trend for the samples, which have been spilitised to varying degrees. It is suggested that the basalts formed as a result of a fissure type of eruption along the fracture zone. Subsequently, some of the basalts were spilitised probably due to hydrothermal solution, possibly the result of tectonic activity along the fracture zone.