Estilos eruptivos de basaltos cenozoicos del oeste de Santa Cruz extraandina, Argentina

PONCE, J.F.; GONZÁLEZ GUILLOT, M.

Tucuman

Congreso; XX Congreso Geológico Argentino; 2017

Characteristics of Pliocene basaltic flows and volcanoes in Patagonia are presented. The basalts were erupted during the post-plateau stage in a slab window model. While most of the post-plateau emissions occurred through scoria or spatter cones, along the western flank of the mesetas the effusions appear to have occurred through lava shields of scutulum type. One representative example occurs on the meseta Desocupada, north of Viedma lake, where the shield also shows evidences of activity after the retreat of piedmont glaciers. This suggests the slab window model should be revised for the western basalts and to consider, in addition, a mechanism of lithospheric relaxation and isostatic rebound for the genesis and/or ascent of the magmas