INFLATED LAVA FLOW IN THE SOMÚN CURÁ PLATEAU, EXTRAANDEAN ARGENTINE PATAGONIA

REMESAL, M; PARICA, C A,

Heidelberg

Congreso; 24th Colloquium on Latin American Earth Sciences; 2017

Universität Heidelberg

The Somún Curá plateau exposes a landscape of coalescence basaltic flows with a variety of landforms, very similar to tho¬se described as inflated pahoehoe sheet flows. Minor features such as lava rise, tumuli and squeeze-up are associated. Cross-sectional profiles in the natural sec-tions (Rincón de Chipauquil, Rincon del Salado, Rincón de Pajalta, Rincón de los Berros, etc) of the basaltic plateau boundary expose characteristics of inflated lava flow (Hon et al 1994). Cross sections showing internal flow structures such as columnar and platy joints, pipe vesicles, vesicle cylinders, and continuous horizontal vesicle sheets were identified. The textural analyses of flows show that the crust of the lava flow is commonly characterized by an upper layer of texture pa-hoehoe, which is rich in spherical vesicles.Somún Curá plateau extends over an area of approximately 20000km2 and inflated sheet flows 10-15 km long and up to 4 km wide, with sub-horizontal top surface was recognized. All the basaltic lava flows coalesced to arrange the plateau and they are radiated from the Alta Sierra.In the field and images can be observed how toes of a basaltic flow progress by a steady supply of lava emission giving lava rise and apophyses. In the interior of this irregular relief thin deposit of aeolian sand are accumulated.