Resumo

LOPEZ I., Julián A.  e  ZULUAGA C., Carlos A.. MACUIRA GNEISS:: TECTONIC EVOLUTION OF THE PALEOZOIC METAMORPHIC ROCKS, ALTA GUAJIRA - COLOMBIA. bol.geol. [online]. 2012, vol.34, n.2, pp.15-36. ISSN 0120-0283.

The Macuira Gneiss is a Paleozoic metamorphic unit that outcrops in the Simarua, Jarara and Macuira ranges, Alta Guajira. It is composed by a lithologies metamorphosed under amphibolite facies P-T conditions and consist of amphibolitic and quartz feldspathic gneisses, amphibolites, schists, pegmatites, calc-silicated rocks and marbles, with migmatization evidences in gneisses and amphibolites. Five foliations (S_1-5) and three folding events (F_1-3) were identified and interpreted as product of two metamorphic events, developed in a progressive barrovian metamorphic gradient of intermediate pressure with intermediate P-T ratio, interpreted as product of continental collision tectonics. This unit is important in understanding of the tectonic evolution of the Alta Guajira and Caribbean because it records different deformational phases pre-, syn- and post-migmatitic, that could be related with different tectonic episodes: the first associated with the collision between Laurasia and Gondwana (Alleghanian Orogeny - Late Paleozoic), and the second related with the Caribbean Plate evolution (Andean Orogeny - Meso-Cenozoic).

Palavras-chave : Migmatites; Deformation; Alleghanian orogeny; Alta Guajira; Colombia.

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