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Soda-granites from South of Tatanagar, Bihar, India

Published online by Cambridge University Press:  01 May 2009

A. K. Banerji  and
A. K. Talapatra
A. K. Banerji
Affiliation:
Geology Department, Presidency College, Calcutta, India.
A. K. Talapatra
Affiliation:
Geology Department, Presidency College, Calcutta, India.
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Abstract

The nature and origin of some soda-granites from the western part of the Singhbhum shear zone, Bihar, India, are discussed. These soda-granites are responsible for copper sulphide, apatite-magnetite, and uraniferous mineralization within the shear zone. Earlier workers regarded these rocks as sheared materials representing a portion of the high sodic residual liquid from the neighbouring Singhbhum granite magma. The present work indicates that these rocks are migmatitic in nature and are the products of progressive replacement of pre-existing pelitic and semi-pelitic schists by felspathic materials. Migmatization is essentially post-shearing in age while the Singhbhum granite is pre-shearing in age. The migmatitic materials appear to have been derived by the partial melting of the Singhbhum granite during shearing, particularly in depth, as a result of sudden release of confining pressure consequent upon shearing and generation of heat caused by friction at the base of the shear zone. The resulting liquids, which were albite rich, found easy passage through the shear zone and brought about migmatization and mineralization in its wake.

Type
Articles
Information
Geological Magazine , Volume 103 , Issue 4 , August 1966 , pp. 340 - 351
Copyright
Copyright © Cambridge University Press 1966

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References

REFERENCES

Banerji, A. K., 1957. On some features of Soda-granites from south of Tatanagar, Singhbhum District, Bihar, India. Science & Culture, 23, 146–7.Google Scholar
Banerji, A. K., 1958. On the origin of the apatite-magnetite veins around Ramchandra Pahar, south of Tatanagar, Bihar, India. Science & Culture, 24, 141–2.Google Scholar
Banerji, A. K., 1961. Structure and stratigraphy of part of northern Singhbhum, South of Tatanagar, Bihar. Proc. Nat. Inst. Sci. India, 30 A, 486–510.Google Scholar
Banerji, A. K., 1962. Cross folding, migmatisation and ore localisation along part of the Singbhum shear zone, south of Tatanagar, Bihar, India. Econ. Geol., 57, 50–71.CrossRefGoogle Scholar
Dunn, J. A., and Dey, A. K., 1942. The geology and petrology of eastern Singhbhum and surrounding areas. Mem. geol. Surv. India, 69, Pt. II.Google Scholar
Friedman, G. M., 1960. Chemical analyses of rocks with the petrographic microscope. Am. Miner., 45, 69–78.Google Scholar
Gorai, M., 1951. Petrological studies in plagioclase twins. Am. Miner., 36, 884–901.Google Scholar
Sarkar, S. N., and Saha, A. K., 1963. On the occurrence of two intersecting pre-Cambrian orogenic belts in Singhbhum and adjacent areas, India. Geol. Mag., 100, 69–92.CrossRefGoogle Scholar