Morphology and petrography of pumice from the Central Indian Ocean Basin

Abstract

Majority of pumice are equant with high Corey's shape factor values. Petrographic studies indicate flow bands of isotropic nature, with varied vesicle shape and size, and the diffractograms show them to be mainly composed of amorphous silica together with lesser amounts of crystalline quartz and feldspars. Two types of pumice, without ferromanganese coating and with ferromanganese coating are observed