Subba Rao, T. V. ; Narayana, B. L. ; Gopalan, K. (1994) Rb-Sr age of the Sivamalai alkaline complex, Tamil Nadu Proceedings of the Indian Academy of Sciences - Earth and Planetary Sciences, 103 (3). pp. 425-437. ISSN 0253-4126
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Official URL: http://www.ias.ac.in/j_archive/epsci/103/3/425-437...
Related URL: http://dx.doi.org/10.1007/BF02841531
Abstract
The Sivamalai alkaline complex comprises ferro-, pyroxene-hornblende- and nepheline-syenites. Field relations show that the nepheline syenites followed the emplacement of non-feldspathoidal syenites. Mineralogical data on the syenite suite have been reviewed. The Sivamalai alkaline rocks are not strongly enriched in rare-earth elements like most miaskites. Rb-Sr isotopic analyses of a suite of six samples from the various members of the complex define an isochron corresponding to an age of 623 ±21 Ma (2σ) and initial Sr ratio of 0.70376 ±14 (2σ). This is consistent with a model of fractional crystallization of a parent magma derived from an upper mantle source with apparently no isotopic evidence for more than one magma source for the complex. The Sivamalai alkaline complex represents a Pan-African alkaline magmatic event in the southern granulite terrane of Peninsular India.
Item Type: | Article |
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Source: | Copyright of this article belongs to Indian Academy of Sciences. |
Keywords: | Sivamalai Alkaline Complex; Rb-Sr Whole-rock Isochron; Initial Strontium Ratio; Fractional Crystallization; Rare-earth Element Abundances |
ID Code: | 13578 |
Deposited On: | 12 Nov 2010 15:18 |
Last Modified: | 16 May 2016 22:43 |
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