Abstract
Quartz-pebble conglomerate (QPC) in the Dhanjori basin, a rifted greenstone belt, is known for its gold mineralization. Audio-magnetotelluric (AMT) soundings have been acquired for 32 sites spread in grid fashion for frequency 10kHz to 10 Hz along four parallel profiles. Due to noise conditions in the data only 26 sites have been used for further studies. The site spacing between adjacent AMT sites were ~250 m. The grid spreads over QPCD and Mayurbhang Granite (MG) of rocks. The dimensionality and the directionality analysis hinted towards a complex structure which tempted to perform a 3D inversion of AMT data for full impedance data. To obtain the optimum value of initial uniform half space resistivity, 3D inversion of off-diagonal component of inversion data was performed with various values of resistivity. The optimized value of resistivity was then used to perform 3D inversion for full impedance component with different set of error floor for the impedance component. The final 3D model showed the presence of a continuous conducting feature all along the three profile. Whereas, the southernmost profile showed three well developed conductors. The model corroborates well with electrical resistivity tomography (ERT) sections and GSI borehole which lies within the same geological domain. The borehole intercepted sulphide mineralization with varying concentration from the near surface to ~ 100m. The near surface conducting heterogeneity thus is attributed to sulphide mineralization.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Acharyya, S.K., Gupta, A. and Orihashi, Y. (2010) Neoarchaean–Paleoproterozoic stratigraphy of the Dhanjori basin, Singhbhum Craton, Eastern India: And recording of a few U–Pb zircon dates from its basal part. Jour. Asian Earth Sci., v.39, pp.527–536.
Anhaeusser, C.R. (1976) The nature and distribution of Archaean gold mineralization in southern Africa: Minerals Sci. Engg., v.8, pp.46–84.
Bahr, K. (1991) Geological noise in magnetotelluric data: a classification of distortion types. Phys Earth Planet. Inter., v.66, pp.24–38.
Bandopadhyay, P.C. and Sengupta, S. (2004) The paleoproterozoic supracrustal Kolhan Group in Singhbhum craton, India and the Indo–African supercontinent. Gondwana Res., v.7, pp.1228–1235.
Brasse, H., Lezaeta, P., Rath, V., Schwalenberg, K., Soyer, W., and Haak, V. (2002) The Bolivian altiplano conductivity anomaly. Jour. Geophys. Res., Solid Earth, v.107(B5), doi:10.1029/2001JB000391.
Colvine, A.C., Andrews, A.J., Cherry, M.E., Durocher, M.E., Fyon, A.J., Lavigne, M.J., Macdonald, A.J., Marmont, S., Poulsen, K.H., Springer, J.S., and Troop, D.G. (1984) An integrated model for the origin of the Archaean lode gold deposits: Ontario Geol. Surv. Open–File Rept. 5524, 98p.
Das, L. K., Dasgupta, K. K., and De, M. K. (2008) Mineral potential of Dhanjori Metavolcanics, East Singhbhum, Jharkhand. Indian Minerals, v.61, pp.193–200.
Egbert, G.D., and Kelbert, A. (2012) Computational recipes for electromagnetic inverse problems. Geophys. Jour. Internat., v.189, pp.251–267. DOI: 10.1111/j.1365–246X.2011.05347.x.
Foster, R. P. (1985) Major controls of Archaean gold mineralization in Zimbabwe: Geol. Soc. South Africa Trans., v.88, pp.109–133.
Groves, D.I., Phillips, G.N., Ho, S.E., and Houstoun, S.M. (1985) The nature, genesis and regional controls of gold mineralization in Archaean greenstone belts of the Western Australian Shield: A brief review: Geol. Soc. South Africa Trans., v.88, pp.135–148.
Gupta, A. (1985) Stratigraphy and petrochemistry of Dhanjori greenstone belt, eastern India. Quart. Jour. Geol. Min. Met. Soc. India, v.57, pp.248–263.
Gupta, A., Singh, R.K. and Shalivahan (2018) Investigation of auriferous mineralization over Greenstone Schist Belt of Dhanjori Basin, Eastern India using 2–D ERT and IP surveys (Accepted).
Haque, M.W., Dutta, S.K. (1996) Investigation for gold mineralization associated with shallow level acid–basic–ultrabasic rocks in Dhanjori basin along possible craton margin, East Singhbhum district, Bihar. Rec. Geol. Surv. India, v.129, pp.147–149.
Heinson, G.S., Direen, N.G., and Gill, R.M. (2006) Magnetotelluric evidence for a deep–crustal mineralizing system beneath the Olympic Dam iron oxide copper–gold deposit, southern Australia. Geology, v.34, pp.573–576. DOI: 10.1130/G22222.1.
Jayananda, M., Peucat, J.J., Chardon, D., Rao, B.K., Fanning, C.M. and Corfu, F. (2013) Neoarchaean greenstone volcanism and continental growth, Dharwar craton, southern India: constraints from SIMS U–Pb zircon geochronology and Nd isotopes. Precambrian Res., v.227, pp.55–76.
Jones, A.G., and Garcia, X. (2003) Okak Bay AMT data–set case study: Lessons in dimensionality and scale. Geophysics, v.68, pp.70–91. DOI: 10.1190/1.1543195.
Kelbert, A., Meqbel, N., Egbert, G.D., and Tandon, K. (2014) ModEM: A modular system for inversion of electromagnetic geophysical data. Computers & Geosciences, v.66, pp.40–53. DOI: 10.1016/j.cageo.2014.01.010.
Livelybrooks, D., Mareschal, M., Blais, E. and Smith, J.T. (1996) Magnetotelluric delineation of the Trillabelle massive sulfide body in Sudbury, Ontario. Geophysics, v.61, pp.971–986. DOI: 10.1190/1.1444046.
Mahadevan, T.M. (1988) Characterization and genesis of Singhbhum uranium province India, In: Recognisation of Uranium Provinces, IAEA, pp.337–369.
Mazumder, R. (2002) Sedimentation history of the Dhanjori and Chaibasa formations, eastern India and its implications. Unpublished Ph. D. thesis (Kolkata, India: Jadavpur University), 119p.
Mazumder, R. (2005) Proterozoic sedimentation and volcanism in the Singhbhum crustal province, India and their implications. Sediment. Geol., v.176, pp.167–193.
Meju, M.A. (2002) Geoelectromagnetic exploration for natural resources: models, case studies and challenges. Surv. Geophys., v.23, pp.133–206. DOI: 10.1023/A:1015052419222.
Pirajno, F. (2007) Mantle plumes, associated intra plate tectonomagmatic processes and ore systems. Episodes, v.30, pp.6–19.
Queralt, P., Jones, A.G. and Ledo, J. (2007) Electromagnetic imaging of a complex ore body: 3D forward modeling, sensitivity tests, and downmine measurements. Geophysics, v.72, pp.F85–F95, DOI: 10.1190/1.2437105
Roy, A., Sarkar, A., Jeyakumar, S., Aggrawal, S.K., Ebihara, M., (2002) Sm–Nd age and mantle characteristics of the Dhanjori volcanic rocks, Eastern India. Geochem. Jour., v.36, pp.503–518.
Shalivahan, Sinharay R.K. and Bhattacharya B.B. (2006) Remote reference magnetotelluric impedance estimation of wideband data using hybrid algorithm. Jour. Geophys. Res., v.111, pp.B11103–B11109.
Singh, S., Maurya, V.P., Singh, R.K., Shalivahan, Tripathi, A.K., and Adhikari, P.K. (2017) Audio magnetotelluric Investigation of Sulfide Mineralization in Proterozoic–Archean Greenstone belts of Eastern Indian Craton. Jour. Earth System Sci., v.127(34), pp.1–18.
Swift, C.M. (1967) A magnetotelluric investigation of an electrical conductivity anomaly in the South Western United States. PhD Thesis Massachusetts Institute of Technology.
Tuncer, V., Unsworth, M.J., Siripunvaraporn, W., and Craven, J. A. (2006) Exploration for unconformity–type uranium deposits with audio magnetotelluric data: A case study from the McArthur River mine, Saskatchewan, Canada. Geophysics, v.71, pp.B201–B209.
Zhang, P., Chouteau, M., Mareschal, M., Kurtz, R. and Hubert, C. (1995) High frequency magnetotelluric investigation of crustal structure in north central Abitibi, Quebec, Canada. Geophys. Jour. Internat., v.120, pp.406–418. DOI:10.1111/j.1365–246X.1995.tb01828.x.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Singh, R.K., Gupta, A.K., Maurya, V.P. et al. 3D Inversion of Audio Magnetotelluric Data for Sulphide Mineralization over Dhanjori Basin. J Geol Soc India 93, 213–217 (2019). https://doi.org/10.1007/s12594-019-1154-4
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12594-019-1154-4