Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-17T15:07:24.620Z Has data issue: false hasContentIssue false
  • English
  • Français

Differentiated dyke rocks of Mer Mundwara, Rajasthan and their metallogenic significance

Published online by Cambridge University Press:  01 May 2009

Sivaramasubramania Viswanathan
Sivaramasubramania Viswanathan
Affiliation:
Indian Institute of Technology, Bombay-400 076, India
Get access Rights & Permissions [Opens in a new window]

Summary

The differentiated dyke rocks of Mer Mundwara comprise a subalkaline series which includes basalts and dolerites, and an alkaline series which includes theralites, porphyritic alkali syenites and nepheline syenites. These intrude into the coarse grained Precambrian granites which, in their turn, are subjacent bodies in the Aravalli system of metamorphic complex of archaean age. Absolute age of basic volcanics is 56±8 Ma, thus relating their emplacement to Deccan Trap volcanism in the Cretaceo-Eocene times in Central and Western India. Petrochemical characteristics of the basic rocks exemplify an alkaline character and so indicate that the basaltic magma of Mer Mundwara is tectonically and genetically different from the Deccan basalts which are in the main tholeiitic. The geological setting, petrography and major and minor element chemistry (Na > K and abundance of Nb, Co, Sn and V) relegate the dyke rock suite to the alkaligabbroic formations of Borodin (1974) with their parent magmatic source in the upper mantle. The alkaline igneous rocks of Mer Mundwara strongly suggest a possible occurrence of rare earths, niobium, zirconium and fluorine in industrial concentrations and also thorium and phosphorus.

Type
Articles
Information
Geological Magazine , Volume 114 , Issue 4 , July 1977 , pp. 291 - 298
Copyright
Copyright © Cambridge University Press 1977

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baskina, V. A. 1974. Characteristics of contrasting volcanic associations. In Problems of Magmatic Formations, pp. 158–78. Moscow: Navuka.Google Scholar
Belousov, V. V. 1964. Influence of tectonic activation and development of earth's crust. In Activated Zones of Earth's Crust, pp. 7–13. Moscow: Navuka.Google Scholar
Borodin, L. S. 1972. Regularity of distribution of rare elements as criteria of depth of origin of alkaline magmas. In First International Geochemical Congress, Magmatic Processes, pp. 463–83. Academy of Sciences, U.S.S.R., Moscow.Google Scholar
Borodin, L. S. 1974. Problems of formations of alkaline rocks. In Problems of Magmatic Formations, pp. 120–57. Moscow: Navuka.Google Scholar
Coulson, A. L. 1933. The geology of Sirohi state, Rajputana. Mem. geol. Surv. India 63, part I, 83–94.Google Scholar
Ginsberg, A. I. & Karaeva, Z. G. 1974. Criteria relating rare element deposits to magmatism. In Magmatism and ore Formation, pp. 25–43. Moscow: Navuka.Google Scholar
Macdonald, G. A. & Katsura, T. 1964. Chemical composition of Hawaiian lavas. J. Petrology 5, 82–133.CrossRefGoogle Scholar
Sharma, T. R. 1969. Magmatic differentiation in the Mundwara igneous complex, Sirohi district, Rajasthan. J. Ind. Geo. Sci. Ass. 11, 79–94.Google Scholar
Subramanyam, N. P., Murali, A. V. & Rao, G. V. 1972. Age of Mundwara Igneous complex. Curr. Sci. 41, N. 2.Google Scholar
Sukheswala, R. N. & Poldervaart, A. 1958. Deccan basalts of the Bombay area. Bull. geol. Soc. Am. 69, 1475–94.CrossRefGoogle Scholar
Viswanathan, S., Krishnamoorthy, N. & Shanmugam, K. 1971. Petrography and petrochemistry of the basalt sequences around Mahape, Mumbra and Kalyan, Maharashtra, India. Bull. Volcan. 4, 1110–28.CrossRefGoogle Scholar
Viswanathan, S. & Chernov, V. I. 1975. Petrography and petrochemistry of the dyke rocks of Mer Mundwara, India. Geology and Prospecting, Moscow (in the press).Google Scholar
Zavaritsky, A. N. 1955. Igneous Rocks, p. 479. Academy of Sciences of the U.S.S.R., Moscow.Google Scholar