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

V. Subramanyan ¹

Affiliations
1 Department of Applied Geology, University of Saugar, Sagar, IN

Abstract

Transported, radioactive (up to about 1,000 ppm of U) limonite occurs in Lota Pahar, which is shown to be the westernmost extension of uranium mineralization in the Singhbhum thrust belt. Limonite might have acquired the uranium content by the adsorption of uranyl ions on the colloidal ferric oxide hydrate. This radioactive limonite served as a prospecting aid in the discovery of uraniferous breccia in the Lota Pahar ridge and the environs.

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V. Subramanyan ¹

Affiliations
1 Indian Institute of Technology, Bombay 400076, IN

Abstract

Superposed river-valleys have all along been generally classified as transverse valleys in geomorphic literature. A study of some unquestionably superposed rivervalleys reveals that this transverse relation to the exhumed geological structure is not always necessary. How a river-valley, which originates on a covermass, gets superposed on the older rocks, after cutting through the former, will depend on the orientation of the exhumed features vis-a-vis the river-valley that is getting superposed on them. If the superposition takes place onto ancient valleys that are themselves structure controlled, the superposed river-valleys will then be aligned along these older structures and not transverse to them. A few such significant cases are discussed.

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