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Eruption of basaltic magma at Tor Zawar, Balochistan, Pakistan on 27 January 2010: geochemical and petrological constraints on petrogenesis

Published online by Cambridge University Press:  05 July 2018

A. C. Kerr*
Affiliation:
School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, UK
M. Khan
Affiliation:
Department of Geology, University of Balochistan, Quetta, Pakistan
I. McDonald
Affiliation:
School of Earth and Ocean Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, UK
*

Abstract

On 27 January 2010 a small eruption of basaltic lava occurred 75 km NE of Quetta, Pakistan. This was highly unusual – no eruptions from this magmatically inactive area have ever been reported. Two petrographically distinct basalts types were indentified in the vesicular eruptive products. One basalt type consists of completely fresh, light brown glass with a few (<1 vol.%) partially resorbed quartz-rich xenoliths, whereas the other type is non-glassy and the lava is completely devitrified. These types also have slightly different geochemical signatures that can be partially explained by crustal assimilation. Re-melting of local basaltic rocks by short circuiting of a ruptured high-tension electrical cable is considered unlikely. Mantle melt modelling suggests that the lavas have been largely derived from a source in the garnet-spinel transition zone, i.e. well within the lithosphere. It is proposed that localized asthenospheric melting resulted in relatively depleted melts which were substantially contaminated by fusible lithospheric mantle en route to the surface. Further small-scale eruptions cannot be ruled out.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2010

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References

Ambraseys, N. and Bilham, R. (2003) Earthquakes and Associated Deformation in Northern Baluchistan 1892-2001. Bulletin of the Seismological Society of America, 93, 15731605.CrossRefGoogle Scholar
Bhattacharyya, C., Das, S., Banerjee, J. and Pal, S.P. (2002) Rock melt extrusion at Puruliya, west Bengal. Journal of the Geological Society of India, 60, 323327.Google Scholar
Castillo, P.R. (2006) An overview of adakite petro-genesis. Chinese Science Bulletin, 51, 257268.CrossRefGoogle Scholar
Green, D.H. and Falloon, T.J. (2005) Primary magmas at mid-ocean ridges, hotspots, and other intraplate settings: Constraints on mantle potential temperature. Geological Society of America Special Paper, 388, 217247.Google Scholar
Herzberg, C. and O'Hara, M.J. (2002) Plume-Associated Ultramafic Magmas of Phanerozoic Age. Journal of Petrology, 43, 18571883.CrossRefGoogle Scholar
Jadoon, I.A.K. and Khurshid, A. (1996) Gravity and tectonic model across the Sulaiman fold belt and the Chaman fault zone in western Pakistan and eastern Afghanistan. Tectonophysics, 254, 89109.CrossRefGoogle Scholar
Kerr, A.C., Khan, M., Mahoney, J.J., Nicholson, K.N. and Hall, C.M. (2010) Late Cretaceous alkaline sills of the south Tethyan suture zone, Pakistan: Initial melts of the Réunion hotspot? Lithos, 117, 161171.CrossRefGoogle Scholar
Khan, A.T., Kassi, M.T. and Khan, A.S. (2000) The Upper Cretaceous Bibai submarine Fan (Bibai Formation), Kach Ziatrat Valley, western Suleiman Thrust-Fold Belt, Pakistan. Ada Mineralogica Pakistanica, 11, 124.Google Scholar
Khan, M., Kerr, A.C. and Mahmood, K. (2007) Formation and tectonic evolution of the Cretaceous-Jurassic Muslim Bagh ophiolitic complex, Pakistan: Implications for the composite tectonic setting of ophiolites. Journal of Asian Earth Sciences, 31, 112127.CrossRefGoogle Scholar
Le Maitre, R.W. (2002) Igneous Rocks: A Classification and Glossary of Terms. Cambridge University Press, Cambridge, UK.CrossRefGoogle Scholar
Mahoney, J.J., Duncan, R.A., Khan, W., Gnos, E. and McCormick, G.R. (2002) Cretaceous volcanic rocks of the South Tethyan suture zone, Pakistan: implications for the Reunion hotspot and Deccan Traps. Earth and Planetary Science Letters, 203, 295310.CrossRefGoogle Scholar
Manimaran, G., Sivasubramanian, P. and Senthiappan, M. (2001) Rock melt intrusion at Abishekapatti, Tirunelveli district, Tamil Nadu. Journal of the Geological Society of India, 57, 464466.Google Scholar
McDonald, I. and Viljoen, K.S. (2006) Platinum-group element geochemistry of mantle eclogites: a reconnaissance study of xenoliths from the Orapa kimberlite, Botswana. Transactions of the Institute of Mining and Metallurgy, Section B, 115, 8193.Google Scholar
McKenzie, D. and O'Nions, R.K. (1995) The source regions of ocean island basalts. Journal of Petrology, 36, 133159.CrossRefGoogle Scholar
Meyzen, C.M., Toplis, M.J., Humler, E., Ludden, J.N. and Mevel, C. (2003) A discontinuity in mantle composition beneath the southwest Indian ridge. Nature, 421, 731733.CrossRefGoogle Scholar
Miller, D.J. and Kelley, J. (2004) Low temperature alteration of basalt over time: a synthesis of results from Ocean Drilling Program Leg 187. Proceedings of the Ocean Drilling Program, Scientific Results, 187, 129.Google Scholar
Miyashiro, A. (1978) Nature of alkalic volcanic rock series. Contributions to Mineralogy and Petrology, 66, 91104.CrossRefGoogle Scholar
Murton, B.J., Tindle, A.G., Milton, J.A. and Sauter, D. (2005) Heterogeneity in southern Central Indian Ridge MORB: Implications for ridge-hot spot interaction. Geochemistry, Geophysics, Geosystems, 6, Q03E20. doi:10.1029/2004GC000798.CrossRefGoogle Scholar
Nauret, F., Abouchami, W., Galer, S.J.G., Hofmann, A.W., Hemond, C., Chauvel, C. and Dyment, J. (2006) Correlated trace element-Pb isotope enrich ments in Indian MORB along 18-20°S, Central Indian Ridge. Earth and Planetary Science Letters, 245, 137152.CrossRefGoogle Scholar
Pearce, J.A. (1996) A user's guide to basalt discrimination diagrams. Pp. 79-113 in: Trace Element Geochemistry of Volcanic Rocks: Applications for Massive Sulphide Exploration (D.A. Wyman, editor). Geological Association of Canada, Short Course Notes, 12.Google Scholar
Rana, A.N. and Akhtar, S.S. (2010) Preliminary Report on Eruption of Molten Material in Tor Zawar Mountain, Sari, Ziarat, Balochistan on January 27, 2010. Information Release No. 891, Geological Survey of Pakistan, Islamabad, 24 pp.Google Scholar
Salters, V.J.M. and Stracke, A. (2004) Composition of the depleted mantle. Geochemistry Geophysics Geosystems, 5, Q05B07, doi:10.1029/ 2003GC000597.CrossRefGoogle Scholar
Siddiqui, R.H., Khan, I.H. and Aziz, A. (1996) Geology and petrogenesis of hotspot-related magmatism on the northwestern margin of the Indian continent. Proceedings of Geoscience Colloquium, Geoscience Laboratory GSP, 16, 115148.Google Scholar
Sun, S.-s. and McDonough, W.F. (1989) Chemical and isotope systematics of oceanic basalts: implications for mantle composition and processes. Pp. 313—345 in: Magmatism in the Ocean Basins (A.D. Saunders and M.J. Norry, editors). Special Publication, 42, Geological Society of London.CrossRefGoogle Scholar
Thordarson, T., Self, S., Oskarsson, N. and Hulsebosch, T. (1996) Sulphur, chlorine, and fluorine degassing and atmospheric loading by the Roza eruption, Columbia River Basalt Group, Washington, USA. Journal of Volcanology and Geothermal Research, 74, 4973.CrossRefGoogle Scholar