Emplacement mechanism of igneous sheet intrusions: A case study in the Malargüe Fault and Thrust Belt and analogue modeling

BENITEZ, A.; VIGIDE, N.; WINOCUR, D.; YAGUPSKY, D.L.

Congreso; Reunión LASI 6: The physical geology of subvolcanic systems: laccoliths, sills and dykes.; 2019

The occurrence of intrusive bodies such as dikesand sills in sedimentary basins has been documentedworldwide. In the northern sector of the NeuquénBasin in Mendoza, Argentina, intrusive bodies arerecognized, preferably emplaced in shales,sandstones and limestones of the Cuyo and Mendozagroups and in the continental sedimentary rocks of theNeuquén Group.The case study of this work corresponds to asector of the Malargüe fold and thrust belt, in thesouth of Mendoza between 35º00´ and 35°30´ LS,where excellent outcrops of intrusive bodies areexhibited. We have recognized punched laccoliths upto 500 meters thick, which have elongatedmorphologies and are linked to linear structures, i.e.thrusts faults or large anticlines. There are alsosmaller igneous sheet intrusions corresponding todikes and sills. The dykes are up to 20 meters thick,while the sills are up to 50 meters thick and 1000meters long. In Los Blancos anticline core, shales andcarbonates of the Cuyo Group are intruded by a sillranging between 30 and 60 meters thick and 1400 mlong