A Newly Discovered Kimberlitic Rock from Pakistan

Zulfiqar Ahmed and George R. McCormick
Centre of Excellence in Mineralogy, University of Baluchistan, GPO Box 43, Quetta, Pakistan
Department of Geology, University of Iowa, Iowa City, Iowa 52242, U.S.A., and Centre of Excellence in Mineralogy, University of Baluchistan, Quetta, 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.

Keywords: kimberlites • mineral chemistry • olivine • phlogopite • monticellite • perovskite • Baluchistan • Pakistan

Mineralogical Magazine; December 1990 v. 54; no. 377; p. 537-546; DOI: 10.1180/minmag.1990.054.377.02
© 1990, The Mineralogical Society
Mineralogical Society (www.minersoc.org)