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Mapping of Greenstone Belts using Aeromagnetic Data in Eastern Dharwar Craton, India


Affiliations
1 Airborne Electromagnetics Division, CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
 

The Eastern Dharwar Craton (EDC) in southern India comprises several thin, linear N–S and NW–SE trending greenstone belts that hold rich economic mineral deposits, surrounded by gneisses and granites of different ages. Very long, linear, high-frequency, high-amplitude magnetic anomalies trending along the E–W, NE–SW, ENE–WSW, NW–SE and N–S directions associated with several sets of dike swarms, fault shears and fractures forming a rhombic pattern over the granite-gneissic terrain in the western part of EDC hindered the recognition of these thin, linear belts. The N–S strike of the belts inthe low-magnetic latitudes posed another limitation to demarcate these zones. A comprehensive relook into the regional aero-magnetic data using the prevailing interpretation techniques through diverse approaches helped identify the feeble magnetic signatures due to known narrow zones and enabled us to map hitherto unknown belts, namely Kurnool and Lattavaram–Atmakuru. 2.5D GM-SYS modelling has been carried out to delineate the vertical disposition of known belts that reaffirmed the existence of newly inferred belts. Isolated magnetic anomalies are also modelled for source-body parameters.

Keywords

Aeromagnetic Data, Greenstone Belts, Low-Magnetic Latitudes, Magnetic Anomalies.
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  • Grant, F. S. and Dodds, J., MAGMAP FFT processing system development notes. Paterson Grant and Watson Limited, 1972.

  • Mendonca, C. A. and Silva, J. B. C., A stable truncated series approximation of the reduction to the pole operator. Geophysics, 1993, 58, 1084–1090.

  • Naqvi, S. M. and Rogers, J. J. W., Precambrian Geology of India, Oxford Monographs on Geology and Geophysics, Oxford University Press Oxford, 1987, p. 223.

  • Drury, S. A., A proterozoic intracratonic basin, dyke swarms and thermal evolution in South India. J. Geol. Soc. India, 1984, 25, 437–444.

  • Mukhopadhyay, D., Structural pattern in the Dharwar craton. J. Geol., 1986, 94, 167–186.

  • Sreeramachandra Rao, K., Regional surveys and exploration for gold in the granite–greenstone terranes of Andhra Pradesh. Spec. Publ. Geol. Surv. India, 2001, 58, 11–27.

  • Manikyamba, C. and Khanna, T. C., Crustal growth processes as illustrated by the Neoarchean intraoceanic magmatism from Gad-wal greenstone belt, Eastern Dharwar Craton, India. Gondwana Res., 2007, 11, 476–491.

  • Manikyamba, C. and Kerrich, R., Geochemistry of alkaline basalts and associated high-Mg basalts from the 2.7 Ga Penakacherla Terrane, Dharwar Craton, India: an Archean depleted mantle-OIB array. Precambrian Res., 2011, 188, 104–122.

  • Dominique, C., Jayananda, M., Chetty, T. R. K. and Peucat, J. J., Precambrian continental strain and shear zone patterns: South Indian case. J. Geophys. Res., 2008, 113, B08402; http:// dx.doi.org/10.1029/2007JB005299.

  • Jayananda, M., Peucat, J., Chardonc, D., Krishna Raod, B., Fanninge, C. M. and Corfuf, F., Neoarchean greenstone volcanism and continental growth, Dharwar craton, southern India: constraints from SIMS U–Pb zircon geochronology and Nd isotopes. Precambrian Res., 2013, 227, 55–76.

  • Ramarao, Ch., Chetty, T. R. K., Lingaiah, A. and Babu Rao, V., Delineation of a greenstone belt using aeromagnetic, Landsat and photogeology – a case study from the South Indian Shield. Geoexploration, 1991, 28, 121–137.

  • Rama Rao, Ch., Bhaskara Rao, D. S. and Atchuta Rao, D., Delineation of possible extension of a schist belt complex in the south-western part of the Cuddapah basin from regional aeromagnetic anomaly map – a directional spectral approach. J. Indian Geophys.Union, 1993, 99–103.

  • Rama Rao, J. V., Balakrishna, B., Murty, N. V. S., Ajaykumar, P., Ramakrishna Rao, M. V., Acharya, R. S. and Sankaram, S. P., A comprehensive view from geophysical signatures over Chitradurga schist belt, Karnataka. J. Geol. Soc. India, 2015, 86, 489–499.

  • Rao, C. R., Babu, B. B. and Kishore, R. K., Depth estimation to the basement of Vibhutigadda and Talluru formations in the southeast fringe of Sandur schist belt from aeromagnetics. J. Geol. Soc. India, 2007, 69, 732.

  • Satish Kumar, K., Srinivas, K. N. S. S. S., Pradeep Kumar, V., Prabhakara Prasad, P. and Seshunarayana, T., Magnetic mapping of banded iron formation of Sandur schist belt, Dharwar Craton, India. J. Geol. Soc. India, 2018, 91, 174–180.

  • Beard, L. S., Detection and identification of north–south trending magnetic structures near the magnetic equator. Geophys. Prospect, 2000, 48, 745–761.

  • Nabighian, M. N., The analyticsignal of two-dimensional magnetic bodies with polygonal cross-section: its properties and use for automated anomaly interpretation. Geophysics, 1972, 37, 507–517.

  • Nabighian, M. N., Additional comments on the analytic signal of two dimensional magnetic bodies with polygonal cross-section. Geophysics, 1974, 39, 85–92.

  • Roest, W. R., Dañobeitia, J. J., Verhoef, J. and Collette, B. J., Magnetic anomalies in the canary basin and the Mesozoic evolution of the central North Atlantic Mar. Geophys. Res., 1992, 14, 1–24.

  • MacLeod, I. N., Jones, K. and Dai, T. F., 3D analytical signal in the interpretation of total magnetic field data at low magnetic latitudes. Exp. Geophys., 1993, 24, 679–688.

  • MacLeod, I. N., Vierra, S. and Chaves, A. C., Analytic signal and reduction-to-the-pole in the interpretation of total magnetic field data at low magnetic latitudes. In Proceedings of the Third International Congress of the Brazilian Society of Geophysics. SBGf, Anais, 1992, pp. 830–835.

  • PGW, Program documentation – MAGMOD version 1.4. Magnetic interpretation software library, Paterson, Grant and Watson Ltd, Toronto, Canada, 1982.

  • Marquardt, D., An algorithm for least-squares estimation of nonlinear parameters. SIAM J. Appl. Math., 1963, 11, 431–441.

  • GEOSOFT OASIS MONTAJ GM-SYS version 7.0. Gravity and magnetic modeling software user guide, Northwest Geophysical Associates, Inc, 2004.

  • Talwani, M., Worzel, J. L. and Landisman, M., Rapid gravity computations for two-dimensional bodies with application to the Mendocino submarine fracture zone. J. Geophys. Res., 1959, 64, 49–59.

  • Talwani, M. and Heirtzler, J. R., Computation of magnetic anomalies caused by two-dimensional bodies of arbitrary shape. In Computers in the Mineral Industries, Part 1 (eds Parks, G. A.), Stanford Univ. Publ. Geol. Sciences, CA, USA, 1964, vol. 9, pp. 464–480.

  • Won, I. J. and Bevis, M., Computing the gravitational and magnetic anomalies due to a polygon. Algorithms and FORTRAN Subroutines.Geophysics, 1987, 52, 232–238.

  • Shuey, R. T. and Pasqulae, A. S., End corrections in magnetic profile interpretation. Geophysics, 1973, 52, 232–238.

  • Cady, J. W., Calculation of gravity and magnetic anomalies along profiles with end corrections and inverse solutions for density and magnetization. Open-File Report No. 77-463. US Geological Survey, Reston, USA, 1977.

  • Cady, J. W., Calculation of gravity and magnetic anomalies of finite-length rightpolygonal prisms. Geophysics, 1980, 45, 1507– 1512.

  • Manikyamba, C., Kerrich, R., Naqvi, S. M. and Ram Mohan, M., Geochemical systematics tholeiitic basalts from the 2.7 Ga Ramagiri–Hungund composite greenstone belt, Dharwar Craton.Precambrian Res., 2004, 134, 21–39.

  • Lowrie, W., Fundamental of Geophysics, Cambridge University Press, UK, 2007, 2nd edn.

  • Reynolds, J. M., An Introduction to Applied and Environmental Geophysics, John Wiley, UK, 2011, 2nd edn.

  • Telford, W. M., Geldart, L. P. and Sherief, R. E., Applied Geophysics, Cambridge University Press, 1990, 2nd edn.

  • Ghosh, D. B., Sastry, B. B. K., Rao, A. J. and Rahim, A. A., Ore environment and ore genesis in Ramagiri schist belt, Andhra Pradesh, India.Econ. Geol., 1970, 65, 801–814.

  • Ramakrishnan, M. and Sundaravanan, D., Differentiated gabbro granophyre composite sill from Ramagiri Greenstone Belt, Andhra Pradesh. J. Geol. Soc. India, 1990, 35, 367–369.


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  • Mapping of Greenstone Belts using Aeromagnetic Data in Eastern Dharwar Craton, India

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Authors

M. Prasanthi Lakshmi
Airborne Electromagnetics Division, CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
S. Parveen Begum
Airborne Electromagnetics Division, CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
A. Manglik
Airborne Electromagnetics Division, CSIR-National Geophysical Research Institute, Hyderabad 500 007, India
D. Seshu
Airborne Electromagnetics Division, CSIR-National Geophysical Research Institute, Hyderabad 500 007, India

Abstract


The Eastern Dharwar Craton (EDC) in southern India comprises several thin, linear N–S and NW–SE trending greenstone belts that hold rich economic mineral deposits, surrounded by gneisses and granites of different ages. Very long, linear, high-frequency, high-amplitude magnetic anomalies trending along the E–W, NE–SW, ENE–WSW, NW–SE and N–S directions associated with several sets of dike swarms, fault shears and fractures forming a rhombic pattern over the granite-gneissic terrain in the western part of EDC hindered the recognition of these thin, linear belts. The N–S strike of the belts inthe low-magnetic latitudes posed another limitation to demarcate these zones. A comprehensive relook into the regional aero-magnetic data using the prevailing interpretation techniques through diverse approaches helped identify the feeble magnetic signatures due to known narrow zones and enabled us to map hitherto unknown belts, namely Kurnool and Lattavaram–Atmakuru. 2.5D GM-SYS modelling has been carried out to delineate the vertical disposition of known belts that reaffirmed the existence of newly inferred belts. Isolated magnetic anomalies are also modelled for source-body parameters.

Keywords


Aeromagnetic Data, Greenstone Belts, Low-Magnetic Latitudes, Magnetic Anomalies.

References





DOI: https://doi.org/10.18520/cs%2Fv118%2Fi9%2F1420-1431