a. Mylonitic foliation common throughout the Sausar belt; note rootless fold on the right; b.Chilpi Ghat Group rocks rise to the north and southwest of the peneplained Malanjkhand Granite tract on the foreground; c. sharp bend in the mineralised quartz vein under mining at Malanjkhand; brittle deformation in the wall rock granite is also notable; d. contact between the Malanjkhand Granite at bottom right corner and the quartzite of the Chilpi Ghat Group south of the copper mine; 2-5 cm thick crush grit is noted at such contacts; d. disintegration of the above quartzite to form 'autoclastic conglomerate to the west of the copper mine; f. greywacke (invariably of lavender colour) of the Chilpi Ghat Group south of the copper mine; slicing of the rock and convoluted quartz veins indicate gliding deformation.  

Contexts in source publication

Context 1

... gneisses to the northeast of Nagpur city in central India. DT (Figs. 1 & 2). The belt is boat-shaped, concavity in the west-central part pointing towards the north. It contains most of India's manganeseore deposits and therefore, geologically well-studied (Fermor,1909 ;Narayanswami et.al, 1963;Roy 1966Roy , 1981. But due to intense deformation ( Fig. 4a), the stratigraphic sequence and the origin of the ores remain controversial ( Sukla and Anadalwar, 1973;Fermor, 1911;Basu, 2007b). The intense deformation has been ascribed to collision between the Bundelkhand proto-continent containing the Sausar belt and the Tirodi Gneiss in the north, and the Bastar or Deccan proto-continent ...

Context 2

... tract east of Balaghat needs separate treatment to clear certain stratigraphic ambiguity. The emplacement of the Malanjkhand Granite (MG) about 60 km east of Balaghat town is considered here to have played the most important role in the tectonic evolution of the Sausar belt besides others. The metasedimentary rocks around Malanjkhand Granite (Fig. 3 & 4b) have variously been described as Sausars, Chilpi, Bharweli, and Chilpi Ghat Groups. The position, including the metasediment-granite relationship is examined below. The MG body is 1400 sq. km in area, mushroomed towards the north and northwest, and with large apophyses to the southwest and SSE. Its tortoise-like shape is evident in ...

Context 3

... parts of the Bundelkhand granitic massif, forming the basement, over hundreds of km. The occurrence of a polymictic 'conglomerate' at the contact in a deformed area is no final proof of younger status of the sedimentary package. The highly angular fine grained grits at the contact of granite and the orthoquartzite of the Chilpi Ghat package (Fig. 4d) is a sign of gliding, arguably due to expansion of granite resulting in bumping of the granite on the host. All stages of fracturing of quartzite and rolling of the fragments into pebble-like entities to produce autoclastic conglomerate at the contact of granite and the sedimentary package have been noted (Fig. 4e) at several places, ...

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... of the Chilpi Ghat package (Fig. 4d) is a sign of gliding, arguably due to expansion of granite resulting in bumping of the granite on the host. All stages of fracturing of quartzite and rolling of the fragments into pebble-like entities to produce autoclastic conglomerate at the contact of granite and the sedimentary package have been noted (Fig. 4e) at several places, including along the Son river to the south, and Rigwatola and Bhigwatola villages to the west of Malanjkhand mine. Such autoclastic conglomerates also contain sharp splintery pieces of slaty shale, militating against any sedimentary transport. The forceful interaction between the metasediments and the granite ...

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... worker, however, did not find any granite clast. One such conglomerate body occurs on the southwestern fringe of the copper mine ( Basu, 2007a). It may be noted that a strike ridge of the Chilpi Ghat rocks juts into the granitic tract for 3.5 km (Fig. 3) and besides the granite, the mineralised quartz vein also takes a westerly turn at this point (Figs. 3 & 4c), denoting obstruction by a promontory of older rock (Chilpi Ghat metasediment) to westward invasion of granite. A couple of dolerite dykes in granite also follow this curvilinear trend (Bhargava and Pal, 1999). The numerous dolerites in the mineralised zone have each a central body from which several branches radiate. The Chilpi Ghat ...

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... VOL.9, DECEMBER, 2014 structures absent in the Chilpi Ghat Group. The Chilpi Group overlies the Pitepani andesite, occurring over the Malanjkhand Granite to its SSW (see flat-top hill in Fig 4b), and could even be part of the late Proterozoic Chhattisgarh Supergroup (Ashru K. Chaudhuri and Nitish Das-pers. commn.). ...

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... Deccan basalts did not spread to the north of the Chittaur town -Bundelkhand line from its possible source areas in the south in the Malwa plateau in the Indore-Bhopal region, due to maximum compaction of the terrain by emplacement of batholiths of granites at Bundelkhand. This line has been designated as the Aravalli syntaxis (Basu 2004a, 2007a). Also, the part of the Satpura axis of Deccan Traps between Chhindwara in the west through Mandla town to Amarkantak is canopy shaped over Malanjkhand. ...

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... basin eastern margin shear and west of the Dongargarh Granite main body. No primary kimberlite clan rock is exposed in this basin. The sequence shows a sheet of autoclastic conglomerate (see photograph on the back cover of Geol. Surv. India Spl. Pub. 64), similar in appearance with the one in the Chilpi Ghat sequence in the Malanjkhand area (Fig. 4e). Both involve quartzites. This conglomerate does not contain any granite clast. The sequence at Wairagarh is underlain by Amgaon/ Bengpal Gneiss. A chromite-bearing ultramafic intrusive, about 100m across, occur in the Amgaon Gneiss outside the southern margin of the basin near Pauni. In the east, six kimberlitic diatremes, some ...

Context 9

... origin of the ores. Commenting on the genesis of manganese in the entire Sausar belt is beyond the scope of this paper. However, a few observations are made. This author had noted that the deposit at Bharweli occur in a strong shear zone ( Basu, 2007b) in granite that has been transformed into muscovite schist, banded mylonite and phyllonite (Figs. 4b,4c,4d). But the ore itself is massive and not JOUR. ECON. GEOL. & GEORES. MANAGE., VOL.9, DECEMBER, 2014 sheared. It is located at the intersection of a major shear zone and a minor cross-lineament (Figs.1 & 4a). Coarse grained quartz-muscovite rock has developed at the hangwall. This is product of dynamothermal metamorphism. The ...

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... VOL.9, DECEMBER, 2014 sheared. It is located at the intersection of a major shear zone and a minor cross-lineament (Figs.1 & 4a). Coarse grained quartz-muscovite rock has developed at the hangwall. ...

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... and Kanker-Mainpur (Bastar) show moderate aeromagnetic signature ( ~ -19 nT) pointing to considerable crustal contamination. Prajapati et al. (2004) found gravity high along the suspected northwestward continuation of the Sonakhan belt beneath the Chhattisgarh basin through Bilaspur. To the west of Malanjkhand, Sausar is a highly sheared tract (Fig. 4a) with totally remobilised gneissic basement and dismembered supracrustals. Absence of any type area and marker horizon, and recognition of banded JOUR. ECON. GEOL. & GEORES. MANAGE., VOL.9, DECEMBER, 2014 mylonite that mimics stratified rocks, and of phyllonite that looks like phyllite as sedimentary formations, at least upto the time ...