Petrology and major element geochemistry of granitic rocks from Bela Ophiolite; economic implications
- 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)
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.
- Asrarullah Z.A. and Abbas S.G. (1979)., Ophiolites in Pakistan: an introduction., Geodynamics of Pakistan. Geological Survey of Pakistan, Quetta, 181-192.
- Sarwar G. (1992)., Tectonic setting of the Bela Ophiolites, southern Pakistan., Tectonophy, 207 (3-4), 359-381.
- Ahmed Z. and Ernst W.G. (1999)., Island arc-related, back-arc basinal, and oceanic-island components of the Bela Ophiolite-Melange Complex, Pakistan., Int. Geol. Rev., 41(8), 739-763.
- Khan M. (1999)., Petrological and Structural studies of the ophiolite of the Baran Lak Area, Bela-Khuzdar, District, Balochistan, Pakistan., Ph.D. Thesis (unpublished.), University of Balochistan, Quetta, Pakistan, 147.
- Gnos E., Khan M., Mahmood K., Khan A.S., Shafique N.A. and Villa I.M. (1998)., Bela oceanic lithosphere assemblage and its relation to the Reunion hotspot., TERRA NOVA-OXFORD, 10, 90-95.
- Ahmed Z. (1993)., Leucocratic rocks from the Bela ophiolite, Khuzdar district, Pakistan., Geological Society, London, Special Publications, 74(1), 89-100.
- Jones A.G. (1961)., Reconnaissance Geology of Part of West Pakistan., A Colombo Plan cooperative project, Government of Canada, Toronto, 550.
- Allemann F. (1979)., Time of emplacement of the Zhob Valley ophiolites and Bela ophiolites, Baluchistan (preliminary report)., Geodynamics of Pakistan. Geological Survey of Pakistan, Quetta, 215-242.
- Cox K.G., Bell J.D. and Pankhurst R.J. (1979)., The Interpretation of Igneous Rocks., Allen and Unwin, London.
- Kakar M.I., Collins A.S., Mahmood K., Foden J.D. and Khan M. (2012)., U-Pb zircon crystallization age of the Muslim Bagh ophiolite: Enigmatic remains of an extensive pre-Himalayan arc., Geology, 40(12), 1099-1102.
- Rollinson H. (2009)., New models for the genesis of plagiogranites in the Oman ophiolite., Lithos, 112(3), 603-614.
- Khan S.R., Jan M.Q. and Khan M.A. (2003)., Petrology and Geochemistry of Trondhjemites from the Waziristan Ophiolite, NW Pakistan., Journal of Himalayan Earth Sciences, 36, 49-63.
- Cox D., Kerr A.C., Hastie A.R. and Kakar M.I. (2017)., Petrogenesis of plagiogranites in the Muslim Bagh Ophiolite, Pakistan; Implications for the generation of Archaean continental crust., Geol. Mag, 1-15.
- Jan M.Q., Laghari A., Agheem M.H. and Anjum S. (2014)., Geology and petrography of the Nagar Parkarigneous complex, southeastern Sindh; The Dinsi body., Journal of Himalayan Earth Science, 47(2), 1-14.
- Lippard S.J., Shelton A.W. and Gass I.G. (1986)., The ophiolite of Northern Oman., Mem. Geol. Soc. London., 11, 178.
- Boudier F., Ceuleneer G. and Nicolas A. (1988)., Shear zones, thrusts and related magmatism in the Oman ophiolite: initiation of thrusting on an oceanic ridge., Tectonophy., 151(1-4), 275-296.
- Pedersen R.B. and Malpas J. (1984)., The origin of oceanic plagiogranites from the Karmoy ophiolite, western Norway., Contrib. Min. Petrol., 88(1-2), 36-52.