Petrology of the Anorthosite Suite East of Bela, District Gaya, Bihar

Anorthosite suite east of Bela in Gaya District, Bihar, comprises: Anorthosite (s. sir.); gabbroic anorthosite and (meta-) gabbro. The rocks occur as isolated blocks and pods in granitoids. Plagioclase in the anorthositic rocks has bimodal character, compositional range from Anso to An73, low structural state and high K/Rb ratio. The chief mafic constituent in the suite is hornblende. Fe-Ti oxide minerals (ilmenite and ilmenomagnetite) occur as pockets associated with the suite. The anorthosite suite may represent detached blocks of an original labradorite type massif. Some significant attributes of the investigated suite have been compared with those of the neighbouring Bengal anorthosite massif.