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Devarajan, M. K.
- Gold Mineralization in the Mahakoshal Greenstone Belt, Central India: A Preliminary Study
Abstract Views :178 |
PDF Views:2
Authors
Affiliations
1 Operation M.P. II, Geological Survey of India, P.O. Garha, Jabalpur-482003, IN
1 Operation M.P. II, Geological Survey of India, P.O. Garha, Jabalpur-482003, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 52, No 2 (1998), Pagination: 147-152Abstract
Gold Mineralization in the eastern part of the Late Archaean Mahakoshal Belt is observed in sulphidic chert associated with banded ferruginous chert (BFC) and in quartz-carbonate-sulphide veins and quartz-carbonate veins emplaced into argillites, greywackes, carbonaceous phyllite and BFC. In the western part of the Mahakoshal belt gold mineralization is noticed in quartz-carbonate veins intruded along the lithological contacts between metabasalts and dolomitic limestone, and in quartz veins/quartz porphyry dykes within dolomitic limestone. Bulk of the gold mineralization is associated with quartzcarbonate and quartz-carbonate-sulphide veins, emplaced during the initial phase of deformation of the Mahakoshal Belt.Keywords
Economic Geology, Gold, Mahakoshal Belt, Son-Narmada Lineament, Madhya Pradesh.- Earthquake Swarm Activity around Village Bamhori, Seoni District, Madhya Pradesh: A Preliminary Study
Abstract Views :174 |
PDF Views:144
Authors
Affiliations
1 Geological Survey of India, Operation M. P. -II, P.O. Garha, Jabalpur - 482 003, IN
2 Geological Survey of India, Earthquake Geology Division, Central Region, PO.Seminary Hills, Nagpur - 440 006, IN
1 Geological Survey of India, Operation M. P. -II, P.O. Garha, Jabalpur - 482 003, IN
2 Geological Survey of India, Earthquake Geology Division, Central Region, PO.Seminary Hills, Nagpur - 440 006, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 62, No 4 (2003), Pagination: 498-502Abstract
No Abstract.- Ductile Shearing and Syntectonic Granite Emplacement along the Southern Margin of the Palaeoproterozoic Mahakoshal Supracrustal Belt: Evidence from Singrauli Area, Madhya Pradesh
Abstract Views :188 |
PDF Views:2
Authors
Affiliations
1 Geological Survey of India, Central Region, PO. Seminary Hills, Nagpur - 440 006, IN
1 Geological Survey of India, Central Region, PO. Seminary Hills, Nagpur - 440 006, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 59, No 1 (2002), Pagination: 9-21Abstract
A prominent E-W trending, sub-vertical to steep south dipping, ductile shear zone occurs along the southern margin of the Palaeoproterozoic Mahakoshal supracrustal belt of Central India. Shear zone structures have been documented from the supracrustal rocks as well as from the intrusive granites (s.l.) from an area near Singrauli. The supracrustal belt away from the shear zone displays a set of subhorizontal upright folds on E-W to ENE-WSW striking axial planes. The intensity of deformation increases southward; the folds become tight to isoclinal with slight overturning towards the north while the fold hinges arc rotated from the subhorizontal position to sub-vertical or down-dip reclined attitude. Mylonitic foliation within the shear zone is sub-parallel to the axial plane schistosity of the dominant fold-set outside the shear zone. The granitic rocks show both magmatic and solid-state fabrics which are part of a continuum of emplacement and deformation in the shear zone. In the initial stages of solid-state deformation, which gave rise to protomylonites, coarse K-feldspar porphyroclasts behavcd in a brittle manner in an overall bulk ductile deformation in the matrix. With increase in intensity of deformation accompanied by the introduction of fluids, the deformation mechanism in feldspar changed from brittle to ductile. Mylonitic foliation is invariably associated with a pervasive stretching lineation. Shear-sense indicators suggest oblique-slip movement with a large reverse-slip component and a small sinistral strike-slip component. The geometry of the folds and their sequence of development are similar in the rocks within and outside the shear zone. Concordance between the granite plutons and the supracrustal rocks is due to syntectonic emplacement. Low pressure-medium temperature metamorphism in the Mahakoshal supracrustal belt contemporaneous with granite intrusion suggests depth of emplacement about 10- 12 km. The bulk kinematic model involves N-S to NNESSW subhorizontal compression over which was superimposed in the southern part a sinistral shearing movement during progressive transpressional deformation.Keywords
Ductile Shear Zone, Mylonites, Syntectonic Granite, Shear-Sense Indicators, Mahakoshal Group, Palaeoproterozoic, Central India.- Proceedings of the Workshop on Magmatic Ore Deposits
Abstract Views :208 |
PDF Views:82
Authors
Affiliations
1 Geomysore Services India Pvt Ltd, ‘Raja Ikon’, 4th Floor, 89/1, Opposite Hotel Park Plaza, Marathahalli, Bangalore 560 037, IN
1 Geomysore Services India Pvt Ltd, ‘Raja Ikon’, 4th Floor, 89/1, Opposite Hotel Park Plaza, Marathahalli, Bangalore 560 037, IN