LITHOSTRATIGRAPHIC UNITS, PETROGRAPHY ANDS CHEMICALCOMPOSITION OF THE MITÚ MIGMATITIC COMPLEX IN THESURROUNDINGS OF MITÚ, COLOMBIA
Published 2012-02-17
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Abstract
ABSTRACT
Mitú Complex migmatites rocks correlates with the province of ‘Rio Negro- Juruena’ (Brazil). Mitú on the plategeologic 443 in an area of 1,115 km2 approximately where divided into three units called Monzogranite of Mitú, Pringamosa’s Granofels and Neis del Yi; units with macroscopic textural and structural differences, and similar mineralogical composition. The rocks from Mitu’s monzogranite are classified petrographically as monzogranites with syenogranites, granodiorites and subordinated quartz feldspar granofels. The Pringamosa´s Granofels groups granofels and gneisses with homophonous migmatitic structures, nebulite, ophthalmic, schlieren and banded, of granitic composition and Neis del Yí’ groups quartz tube feldspathic gneisses with biotite and large porphyroblasts alkaline feldspar by way of augen together with quartz-feldspar granofels bands with biotite. The essential minerals found in these units are quartz, potassium feldspar (microcline), plagioclase (andesine-oligoclase) and biotite. Accessory minerals are apatite, zircon, monazite, opaque, rutile, allanite, fluorite and hastingsite. Roks from Mitú’s Migmatites Complex are high potassium sub-alkaline, metaluminous and peraluminous affinity, correspond to grains of A type affinity ferrous and magnetite series, with enrichment of REE in samples with monazite.
Keywords: monzogranite, granofels, Mitú, caño Yí
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References
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