Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

G. Lakshminarayana ¹, S. Bhattacharjee ¹

Affiliations
1 Geological Survey of India, Project: Cuddapah Basin, Operations: Andhra Pradesh, Bandlaguda, Hyderabad 500 068, IN

Abstract

The Gandikota Formation consists of 40 - 45 m thick shale - siltstone - quartzite (lower member) and 140 - 190 m thick quartzite and siltstone (upper member). Vertical profile of the lower member represents a coarsening up sequence of prograding shoreline setting. As many as eight qualtzite sheets of 15 to 25 m thickness each, constitue the upper member. The herringbone, tabular and trough cross stratified quartzite, and ripple bedded quartzite and siltstone constitute major sedimentary lithofacies in the upper member quartzite sheets. Palaeocurrent mean was towards NW and NNE. A shallow marine environment with poorly contined tidal channels is envisioned for the deposition of the upper member quartzite sheets.

Keywords

Sedimentology, Gandikota Formation, Middle Prolelozoic, Cuddapah Basin, Andhra Pradesh.

Full Text

     

S. Balakrishnan ¹, R. Madusudanan ², S. Bhattacharjee ³, S. T. Narahari ³, R. Ananthanarayana ³, T. C. Devaraju ⁴

Affiliations
1 Geological Survey of India, Bangalore - 560 078, IN
2 Geological Survey of India, Bangalore - 560078, IN
3 Petrology Division, GSI, Hyderabad - 500 078, IN
4 'Rajamangala', Saptapur, Haliyal Road, Dharwad - 580001, IN

Abstract

No Abstract.

Full Text

   

G. Lakshminarayana ¹, S. Bhattacharjee ¹, Ajit Kumar ¹

Affiliations
1 Geological Survey of India, Operations, Andhra Pradesh, Project: Cuddapah Basin, Bandlaguda, Hyderabad 500068, IN

Abstract

Palaeocurrents of the diamondiferous Banganapalle Formation show convergence towards Nandyal depression in the Kurnool Sub-basin. Localised depocentres, separated by E-W trending ridges, are identified near Kurnool, Paniam, Uppalapadu and Proddatur. These ridges pass through Gani, Banganapalle and Gandikota and have influenced sediment dispersal pattern in the Banganapalle Formation. Provenance for the Banganapalle Formation was mainly the intrabasinal tract occupied by lower Cuddapah sediments, igneous intrusives and the basement located to the west. Deposition commenced in an alluvial environment followed by intertidal setting.

Keywords

Sedimentology, Palaeocurrents, Banganapalle Formation, Diamond, Kurnool Sub-Basin, Cuddapah Basin, Andhra Pradesh.

Full Text

     

S. Ananda Murthy ¹, S. Bhattacharjee ¹

Affiliations
1 Geological Survey of India, Hyderabad-500 068, IN

Abstract

Examination of soil and bed rock samples of pegmatites and metabasalts has helped in identifying an auriferous zone in Guntipalli-Atkur area. The samples analysed anomalous gold values ranging from 0.025 to 4.25 ppm.

Full Text