Abstract
Petrographic studies of Proterozoic pyriteferous granitoids forming basement for upper cretaceous Mahadek sediments from Wahkyn area reveal interesting textural peculiarities of Pyrite. These pyrites also reveal interesting structural peculiarities. The three textural pyrite varieties found in the granitoids are: framboidal, colloform and recrystallised which appear both as composite aggregate as well as independent units. Various textures and variation in reflectivity, microhardness and elemental distribution of the pyrites are described. Average Co/Ni ratio along with the textural manifestation of these pyrites attests their sedimentary origin.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ali, M.A. and Singh, A.K. (1982) A note on uranium mineralisation in cretaceous sedimentary rock near Gomaghat, Khasi hills, Meghalaya. Rec. Geol. Surv. India, v.112,pt.4, pp.17–20.
Barlia, A., Sabatini, G. and Troja, F. (1979) A evaluation of Co/Ni ratio in pyrite as geochemical tool in ore genesis problems. Evidences from southern Tuscany Pyrite deposits. Mineral. Deposita, v.14(3), pp.353–370.
Berner, R.A. (1970) Sedimentary pyrite formation. Amer. Jour. Sci., v.268, pp.1–23.
Chen, T.T. (1978) Colloform and framboidal pyrite from the Cariben deposit. Cand. Mineral., v.16, pp.9–15.
Dhana Raju, R., Paneer Salvem, A. and Virnave, S.N. (1989) Characterization of Upper Cretaceous Lower Mahadek sandstone and its Uranium mineralisation in the Domiasait-Gomaghat-Pedengshakap area, Meghalaya, India. Explor. Res. At. Minerals, v.2, pp.1–27.
Dhana Raju, R., Paneer Salvem and Sinha, R.M. (1996) Petrology and Geochemistry of the Neoproterozoic South Khasi Batholith and related granitiods in Khasi Hills Districts Meghalaya, India and their bearing on Uranium Mineralisation. Explor. Res. At. Minerals, v.9, pp.73–89.
D’ Cruz, E, Mathur, S.K., Padhi, A.K., Sachan, A.S. and Sen, D.B. (1998) on the discovery of uranium mineralisation in Wahkyn Area, West Khasi Hills district, Meghalaya, India. Curr. Sci., v.75, No.11, pp.1117–1119.
Farrand, M. (1970) Framboidal Sulphides precipitated synthetically. Mineral. Deposita, v.5(3), pp.237–247.
Ravi Kaul and Varma, H.M. (1990). Geological evoluation and genesis of the sand stone type Uranium deposit at Domiasiat, West Khasi Hills District, Meghalaya, India Explor. Res. At. Minerals, v.3, pp.1–16.
Love, L.G. (1971) Early diagenetic polyframboidal pyrite primary and redeposited from Wenlockian Denbigh grit group, Conway, North Wales, U.K. Sedimetary Petrology, v.41(4), pp.1038–1044.
Mohapatra, B.K., Paul, A.K. and Sahoo, R.K. (1991) Framboidal-Colloform-recrystallised Pyrite in Volcanic tuffs of Barsuan valley, Orissa. Jour. Geol. Soc. India, v.37, pp.55–62.
Mamallan, R., Awati, A.B., Kak, S.N. and Gupta, K.R. (1995) Effective utilization of geomorphology in uranium exploration: A success story form Meghalaya, northeast India. Curr. Sci., v.68, no.11, pp.1137–1140.
Mazumdar, S.K. (1986). The Precambrian framework of part of the Khasi Hills, Meghalaya. Rec. Geol. Surv. India, v.117(2), pp.1–59.
Paul Ramdhor (1980) The ore minerals and their intergrowths. pp.791–806.
Ranganath, N., Veerbhaskar, D. and Hansoti, S.K. (1995). Petrography of Uraniferous Host Rock Along The Deccan Trap- Lameta-Crystalline Rocks Contact of Lalbara District Mandla, Madhya Pradesh. Gondwana Geological Mag., v.19, pp.11–32
Srivastava, R.A.K. and Melhotra, M.N (1981) Sedimentological studies of the Kaimur sandstones, Central Son valley, Region, India, Geol. Surv. India Misc. Publ., v.50, pp.109–120.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Ranganath, N., Padhi, A.K., Padhi, A.K. et al. Framboidal — colloform — recrystallised pyrite in the granitoids of Wahkyn area, West Khasi hills, Meghalaya. J Geol Soc India 74, 591–596 (2009). https://doi.org/10.1007/s12594-009-0173-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12594-009-0173-y