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Geochemistry and relationships to mineralization of granitic rocks from the Afu Younger Granite Complex, Central Nigeria

Published online by Cambridge University Press:  01 May 2009

E. G. Imeokparia
Affiliation:
Geology Department, University of Ibadan, Ibadan, Nigeria

Summary

Geochemical analyses of fresh bedrock samples indicate that the Afu biotite granites are characterized by enhanced values of a suite of trace elements, including Sn, Nb, W, Zn, Rb, Li, F th, Y and depleted in Ba Sr, and Mn. These geochemical data are also examined by R-mode factor analysis with the primary objective of isolating the significant factors accounting for the sample composition as derived from mineralization, alteration and lithology.

The Orthogonal varimax solution yields a five-factor model that accounts for 76% of the total data variance. Factors 1 (Nb, Rb, Li F) and 3 (Sn, W) can be attributed to the effect of mineralization and postmagmatic alteration; while Factor 2 (Mn, Sr, Ba Zr) is lithological, associated with barren rocks, unaffected by metasomatism. Factor 4 (Th, Y, Ga) and Factor 5 (Pb and Zn) are also associated with prominent mineralization. Thus the mineralized granites are characterized by high concentrations of Sn, Nb, W, Zn, Rb, Li F, Th, Y and Pb but ore formation is considered a product of postmagmatic processes.

Type
Articles
Copyright
Copyright © Cambridge University Press 1982

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