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

C. Mahadevan ¹, V. V. S. S. Tilak ¹, U. Aswathanarayana ¹

Affiliations
1 Department of Geology, Andhra University, Waltair, IN

Abstract

Beta-activity has been determined for 37 rocks (12 gneisses, 7 granites, 7 charnockites. 5 calc-granulites and 6 schists) drawn from various parts of Andhra Pradesh. For 15 samples selected from the above groups, alpha-activity was also determined, for effecting a comparative study of the two sets of measurements. The present work confirms the results of previous studies which showed that the beta-activity of a rock is conditioned by the following mutually-related factors: chemical composition (Fe₂O₃: FeO ratio, silica, potash, alumina, and calcium oxide concentrations), mineralogical composition (quartz, feldspar and heavy mineral contents), and petrogenetic history. The discrepancies in the equivalent uranium content of rocks as deduced from their beta- and alpha-activities, are traced to the variations in the concentration of beta-emitting K⁴⁰ and U : Th ratios.

Full Text

     

U. Aswathanarayana ¹

Affiliations
1 C.P 1947, Maputo, Mozambique, ZA

Abstract

No Abstract.

Full Text

   

V. Divakara Rao ¹, U. Aswathanarayana ², M. N. Qureshy ¹

Affiliations
1 National Geophysical Research Institute, Hyderabad, IN
2 Centre of Advanced Study in Geology, UniversIty of Saugar, Sagar (M.P.), IN

Abstract

With the object of investigating the mode of origin of the Closepet granite, Mysore state, India, integrated geological, geochemical and geophysical studies have been made of the northern part of the pluton as also the adjacent Chitaldurg and Hosdurga granites and Penmsular gneiss. The Joints (post-emplacement'l) in the Closepet granite and the ratios of mineral pairs indicate that (i) the grey and the pink varieties of the Closepet granite and the Chitaldurg granite are comparable to many respects and might have had a common mode of origin, (ii) the Hosdurga granite is distinguishable from the above granites in having a lower amount of quartz and K-feldspar and higher amounts of plagioclase and mafics and (iii) the Peninsular gneiss markedly differs from the Closepet and Chitaidurg granites, and departs from them in the same direction as the Hosdurga granite but in a more accentuated way. A two-stage model for the origin of the Closepet granite is supported by the following petrological evidence presence of two generations of quartz, unzoned anhedral plagioclase, replacement of plagioclase by microcline and the presence of perthite and myrmekite along With K-feldspar and quartz. The Closepet granite was apparently formed by palingenesis (starting from the Peninsular  gneiss) and metasomatism involving enrichment in Si, K and Na, among other elements.

Full Text

     

M. P. Hegde ¹, U. Aswathanarayana ²

Affiliations
1 Hindustan Zinc Limited, Zawar Mines P.O., Udaipur Dist., Rajasthan, IN
2 Centre of Advanced Study in Geology, University of Saugar, Sagar, M.P., IN

Abstract

Sixteen samples of metavolcanics of Ingaldhal have been analysed for sulphur and for Cu, Co, Ni and Zn (in the hydrogen peroxide-ascorbic acid leach solution). There is no visible mineralisation where the S content in the metavolcanics is below 200 ppm. A sulphur content of more than 500 ppm and/or a copper content of more than 200 ppm in the hydrogen peroxide-ascorbic acid leach, may be indicative of economically important copper mineralisation in the Ingaldhal-type metavolcanics. Mineralised metavolcanics are apparently characterised by higher Cu/Ni (> 90)& Cu/Co (> 60) ratios and lower Co/S(< 0.03) & Ni/S (<0.02) ratios than barren metavolcanics.

Full Text

     

U. Aswathanarayana ¹

Affiliations
1 Adviser on Environment & Technology C.P. 1947, Maputo, MZ

Abstract

No Abstract.

Full Text

   

U. Aswathanarayana ¹

Affiliations
1 Maputo, Mozambique, ZA

Abstract

No Abstract.

Full Text

   

U. Aswathanarayana ¹

Affiliations
1 Maputo, Mozambique, ZA

Abstract

No Abstract.

Full Text

   

U. Aswathanarayana ¹

Affiliations
1 Mahadevan International Centre for Water Resources Management, Hyderabad-500082, IN

Abstract

No Abstract.

Full Text

   

U. Aswathanarayana ¹

Affiliations
1 R-16, Shanti Shikara Apts. Somajiguda, Hyderabad - 500 082, IN

Abstract

No Abstract.

Full Text

   

U. Aswathanarayana ¹

Affiliations
1 B-16, Shanti Sikhara Apts. Somajiguda Hyderabad -500 082, IN

Abstract

No Abstract.

Full Text

   

U. Aswathanarayana ¹

Affiliations
1 Hyderabad, IN

Abstract

No Abstract.

Full Text

   

U. Aswathanarayana ¹

Affiliations
1 B-16, Shanti Sikhara Apts, Somajiguda, Hyderabad - 500 082, IN

Abstract

This note seeks to develop a plan of action for the gold industry in India, on the basis of the identification of the lithological environments where gold can be expected to occur, in situ analysis of gold at ppm levels, and using "portable" plants for the extraction of gold at concentration levels of 1-3 g/t , employing the carbon-in-pulp/carbon-in-leach technologies.

Full Text

   

U. Aswathanarayana ¹

Affiliations
1 Mahadevan International Centre for Water Resources Management, Hyderabad, IN

Abstract

No Abstract.

Full Text

   

U. Aswathanarayana

Abstract

No Abstract.

Full Text