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Petrology and major element geochemistry of granitic rocks from Bela Ophiolite; economic implications

Author Affiliations

  • 1Centre of Excellence in Mineralogy, University of Balochistan, Quetta, Pakistan
  • 2Centre of Excellence in Mineralogy, University of Balochistan, Quetta, Pakistan
  • 3Department of Earth and Environmental Sciences, Bahria University Karachi Campus, Pakistan
  • 4Balochistan University of Information Technology, Engineering and Management Sciences, Quetta, Pakistan

Int. Res. J. Earth Sci., Volume 6, Issue (5), Pages 1-8, May,25 (2018)

Abstract

The Bela Ophiolite is one of the largest ophiolites in Pakistan. The ophiolite contains three different types of granitic rocks; epidote granite, albite granite and alkali granite. The outcrops of epidote granite are surrounded by crustal gabbroic rocks and are exposed at two different localities. Albite granite forms an isolated hill and is surrounded by diorite. While the alkali granite is exposed in the south of Bela Ophiolite and found as inlier in the sedimentary successions of Indian Plate passive margin sediments. The geochemistry of these granitic rocks shows that they have more than 60 wt% SiO2 and lowest wt% of TiO2 (0.03- 0.3), CaO(0.2-1) and P2O5(0.01-1), and relatively high Na2O (7-10) concentrations which confirm their acidic nature. The nature and composition of alkali granite indicate that it may be a piece of the Indian continental crust and may be obducted during the emplacement of the Bela Ophiolite Complex. While the petrology of epidote granite and albite granite indicate that they are formed within the gabbro/diorite pluton by either hydrous melting of granulite-amphibolite beneath the peridotite slab or by wet anatexis of isotropic gabbros. Out of the studied granite, epidote and alkali granites have economic uses. They can be used as dimension stone, in buildings, bridges, footpaths, monuments, wall facing, floors, stair and many other designings.

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