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Giant quartz veins (GQVs; earlier referred to as 'quartz reefs') occurring in the Archean Bundelkhand Craton (29, 000 km 2 ) represent a gigantic Precambrian (∼ 2.15 Ga) silica-rich fluid activity in the central Indian shield. These veins form a striking curvilinear feature with positive relief having a preferred orientation NE-SW to NNE-SSW in the Bundelkhand Craton. Their outcrop widths vary from ≤ 1 to 70 m and pervasively extend over tens of kilometers along the strike over the entire craton. Numerous younger thin quartz veins with somewhat similar orientation cut across the giant quartz veins. They show imprints of strong brittle to ductile-brittle deformation, and in places are associated with base metal and gold incidences, and pyrophyllite-diaspore mineralization. The geochemistry of giant quartz veins were studied. Apart from presenting new data on the geology and geochemistry of these veins, an attempt has been made to resolve the long standing debate on their origin, in favour of an emplacement due to tectonically controlled polyphase hydrothermal fluid activity.

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The Karmanasa basin is spread over the Kaimur sandstone (Upper Vindhyan) and marginal Ganga plain with the areal extension of about 7926 km 2. The quantitative approach of the basin development of the Karmanasa River basin was carried out by the morphometric parameters. The drainage network was extracted from SRTM data. The trellis pattern characterizes upstream of the drainage basin, while the dendritic pattern is noticed in middle and downstream of the basin. The drainage density (0.34-0.44) indicates that the basin has highly permeable subsoil and thick vegetative cover. Relatively larger values of form factor (SW-1, SW-2, SW-3, SW-6 and KW) signify higher flow peak for a shorter duration. High values of ruggedness number and relief ratio suggest that Karmanasa basin is prone to soil erosion. The present work shows that the Karmanasa basin is less prone to flood, vulnerable to soil erosion and a good resource of surface water. This study would help to utilize the water resources and extended for sustainable development of the Karmanasa River basin area.

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