A newly discovered kimberlitic rock from Pakistan

Abstract

This first report of the occurrence of a kimberlitic rock in Pakistan is supported by its field relations, textures and mineral chemistry. Linear dykes, lenses, conical and pipe-like bodies, plugs and sills intrude non-orogenic, early Jurassic limestone near the SW extremity of an Eocene-emplaced ophiolite on the transform-type Indian plate margin; far away from the stable Precambrian craton. The rock resembles 'micaceous kimberlites' petrographically and contains olivine, phlogopite, perovskite, chromian spinel, monticellite, chlorite, serpentine, calcite, apatite, pectolite, clinopyroxene, amphibole, nepheline, magnetite and titanomagnetite. The minerals and their microprobe analyses resemble those of kimberlitic rocks.