Geochemistry of Spinifex-Textured Peridotitic Komatiites from Ghatti Hosahalli, Karnataka, Indi
Authors
-
National Geophysical Research Institute, Hyderabad-500 007
B. L. Narayana -
National Geophysical Research Institute, Hyderabad-500 007
S. M. Naqvi
Abstract
Spinifex-textured peridotitic komatiites (STPK) of Ghatti Hosahalli have low CaO/Al2O3 ratio (< 1), low TiO2, K2O and high MgO. These STPK have comparable Ni and Co contents with those of the Australian and Canadian shields. These characters support the view that the spinifex-texture observed in these rocks is primary and not the result of later metamorphism. The Al2O3/TiO2 ratios are comparable to those of Chondrites indicating that the STPK are products of partial melting of the Archaean mantle. The STPK of Ghatti Hosahalli arc overlain by exhalative chemical precipitates and argillaceous metamorphosed sediments like bedded-barytes, fuchsite-quartzites and kyanite-mica schists. It is suggested that Ghatti Hosahalli band is a relic of an early Archaean greenstone belt.Downloads
Issue
Section
Downloads
Published
How to Cite
References
ARNDT, N. T., NALDRETT, A. J. and PYKE, D. R., (1977) Komatiitic and Iron-rich Tholeiitic Lavas of Munro Township, Northeast Ontario. Jour, Petrol., v. 18, pp. 319-367.
HUSSAIN, S. M., NAQVI. S. M. and GNANESHWAR RAO, T., (1979) Geochemistry of mafic-ultramafic rocks from the southern part of the Holenarasipur schist belt, Karnataka, India. (Communicated to Jour. Geol, Soc. India).
NAQVI, S. M., (1976) Physico-chemical conditions during the Archaean as indicated by Dharwar Geochemistry. In: Windley, B. F. (Ed.), 'The Early History (If the Earth', John Wiley & Sons, pp. 289-298.
NARAYANA, B. L., UOAY RAJ, B., AHMAD, S. M. and NAQVI, S. M., (1978) Geochemistry of Fuchslte-quartzltes from Dharwar greenstone belts, Karnataka, India. Presented at Archaean Geochemistry Field Conference, Canada.
NESBITT, R. W. and SUN, S. S., (1976) Geochemistry of Archaean Spinifex-textured peridotites and magnesian and low-magnesian tholeiites. Earth Planet. Sci. Lett., v. 31, pp. 433-453.
RADHAKRISHNA, B. P. and SREENIVASIYA, G., (1974) Bedded barytes from the Precambrian of Karnataka. Jour. Geol. Soc. India, v. 15, pp. 314-315.
VILJOEN, M. J. and VILJOEN, R. P., (1969) Evidence for the existence of mobile extrusive peridotite magma from the Komati Formation of the Onverwacht Group. Trans. Geol. Soc. S. Africa. Spec. Publ. No. 2, UMP-Paper No. 5, pp. 87-112.
VISWANATHA, M. N., RAMAKRISHNAN, M. and NARAYANAN KUTTY, T. R., (1977) Possible spinifex-texture in a serpentinite from Karnataka. Jour. Geol. Soc. India, v. 18, pp. 194-197.
