Geologia del Grupo Los Menucos, Comarca Nordpatagónica, Argentina.

LABUDIA, C. H. Y BJERG, E. A.

La Plata

Congreso; XVI Congreso Geológico Argentino; 2005

Plutonic and volcanic complexes, the last one displaying interbeded sedimentary rocks, constitute the Mesozoic units in the central area of the Nordpatagonian Massif. These Middle to Late Triassic age units crop out in a discontinuous belt extending from Valcheta in the East to Ingeniero Jacobacci in the West, Río Negro province, Argentina. The Triassic volcanism and the associated sedimentary rocks constitute Los Menucos Group, which comprise Vera and Sierra Colorada Formations. Lavas, breccias, tuffs, ignimbrites, pyroclastic fluxes, sandstones, argillite and conglomerates compose the volcano-sedimentary units of Los Menucos Group. The volcanic rocks from Los Menucos area are similar to those cropping out in Sierra Colorada and others localities in Rio Negro province. The field and geological relationships between Los Menucos Group and the Paleozoic and Mesozoic units are discussed in this contribution.