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

K. K. Dar ¹

Affiliations
1 Atomic Minerals Division, Department of Atomic Energy, New Delhi, IN

Abstract

A brief account of the Indian Atomic Energy mineral occurrences with their genetic classification is presented in this paper.

Syngenetic radioactive minerals in small quantities occur in several pre-Cambrian granites and pegmatites, and in some syenites. Many pegmatites are an important source of beryl and to a lesser extent of lepidolite, only some carrying small pockets of radioactive minerals. High-intensity as well as low-temperature hydrothermal epigenetic mineralisation occurs in pre-Cambrian meta-sediments and associated intrusive granites generally of post-Algonkian age. Important uranium deposits are located in the Singhbhum Copper Belt, Bihar. Lately, two uranium occurrences have been discovered in the terra incognita of the Central Himalayas. The sedimentary formations of Peninsular India are essentially thoriferous; sporadic presence of uranium in very small amounts is reported only in a few rare instances, e.g., certain arkosic sandstones, laterites, coals, phosphatic nodules, etc. The problem of continuous replenishment of radium in the Tuwa hot spring, Gujarat, is discussed. The monazite-bearing placer deposits along the 2000 mile long Indian sea-board and some inland placers are described.

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A. V. Sankaran ¹, T. K. Bhattacharyya ¹, K. K. Dar ¹

Affiliations
1 Atomic Minerals Division, Department of Atomic Energy, New Delhi, IN

Abstract

Abundances of the lanthanides, yttrium, scandium and 12 other elements in pegmatitic and hydrothermal uraninites from India and Massif Central, France, are presented and compared with those available in literature. The pegmatitic uraninites exhibit a selective, and the hydrothermal types a complete rare-earth assemblage with Gd markedly high in both. The La-Nd: Sm-Ho: Er-Lu ratio may serve as an index of fractionation. Pegmatitic uraninites show an abnormal distribution of La in excess of Ce. An explanation is offered for this.

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