Abstract
Occurrence of placer gold is reported for the first time in the insitu and colluvial gravels derived from amphibolite/hornblende schist, associated pegmatite and quartz veins of Nagamangala schist belt in Marlagalla -Allapatna areas, Mandya district, Karnataka. Gold occurs in the form of small nuggets, measured up to 3mmx4mm in size and 0.2 gram in weight. The host rock is amphibolite which are intruded by numerous pegmatite and quartz veins. The pegmatites are complex, highly evolved type and contain economic concentration of rare metal bearing minerals viz., columbite-tantalite, beryl and spodumene. Prolonged weathering of these rocks resulted in liberation of gold from host rocks and concentrated in the insitu/eluvial and colluvial gravels. The present finding of gold opens up a new vista for further detailed geological/geochemical exploration to establish and evaluate gold potential in the eluvial, colluvial gravels as well as in the other lithounits of Nagamangala schist belt in Marlagalla-Allapatna areas.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Banerjee, D.C, Ranganath, N., Maithani, P.B. and Jayaram, K.M.V. (1987). Rare Metal bearing pegmatites in parts of southern Karnataka, India. Jour. Geol. Soc. India, v.30, pp.507–513.
Banerjee, D.C., Krishna, K.V.G., Murthy, G.V.G.K., Srivatava, S.K. and Sinha, R.P. (1994). Occurrence of Spodumene in the rare metal bearing pegmatites of Marlagalla-Allapatna area, Mandya district, Karnataka. Jour. Geol. Soc. India, v.44, pp.127–139.
Bibhuranjan Nayak (2011) Gold in the Beach Placer sands of Chavakkad-Ponnani, Kerala Coast, India. Jour. Geol. Soc. India, v.78, pp.345–348.
Cerny, P. (1991) Rare-element granite pegmatites. Anatomy and internal evolution of pegmatite deposits. Geosci. Can., v.18, pp.49–67.
Jones, R.S. and Fleischer, M (1969) Gold in Minerals and the Composition of Native Gold, Geological Survey Circular 612, pp.17.
Krishna, K.V.G. and Thirupathi, P.V. (1999) Rare metal and rare earth pegmatites of Southern India. Exploration and Research for Atomic Minerals, v.12, p. 133–167.
Me Hugh, J. (1983) Atomic Spectroscopy, v.66, pp.4.
Radhakrishna, B.P and Curtis, L.C (1999) Gold in India, Geological Society of India, Bengaluru, 307p.
Radhakrishna, B.P. (2013) Mineral Resources of Karnataka, Geological Society of India, 471p.
Ramakrishnan, M. and Vaidyanadhan, R (2010) Geology of India (Volume-1), Geological Society of India, Bangalore.
Acknowledgement
The authors acknowledge the unstinted efforts of officers associated with Marlagalla area for the first two decades and their immense contributions to the geology and Rare Metal prospecting. The contributions of personnel attached to Marlagalla Prospect are highly appreciated.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Rajendran, R., Jagadeesan, P., Thirupathi, P.V. et al. Occurrence of Placer Gold in the Marlagalla-Allapatna Areas, Mandya District, Karnataka. J Geol Soc India 94, 42–46 (2019). https://doi.org/10.1007/s12594-019-1264-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12594-019-1264-z