Resumo

RODRIGUEZ GARCIA, Gabriel et al. LITHOSTRATIGRAPHIC UNITS, PETROGRAPHY ANDS CHEMICAL COMPOSITION OF THE MITÚ MIGMATITIC COMPLEX IN THE SURROUNDINGS OF MITÚ, COLOMBIA ABSTRACT. bol.geol. [online]. 2011, vol.33, n.1, pp.27-42. ISSN 0120-0283.

Mitú Complex migmatites rocks correlates with the province of ‘Rio Negro- Juruena’ (Brazil). Mitú on the plate geologic 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.

Palavras-chave : monzogranite; granofels; Mitú; caño Yí.

        · resumo em Espanhol     · texto em Espanhol     · Espanhol ( pdf )