ANÁLISIS PETROGRÁFICO PRELIMINAR SOBRE LAS ARENISCAS DE LA FORMACIÓN SANTA CRUZ (MIOCENO MEDIO) EN EL FLANCO NORTE DE LA CUENCA DEL GOLFO SAN JORGE

OLAZABAL, SABRINA; TUNIK, MAISA; PAREDES, JOSE; VALLE, MAURO

San Miguel de Tucuman

Congreso; Congreso Geologico Argentino; 2017

The deposits of the Santa Cruz Formation on the northern flank of the Golfo San Jorge basinlack petrographic studies. This study contributes the first petrography results of aeolian andfluvial sandstones from this formation. The rocks were classified as litharenites andfeldspathic litharenites .Lytic fragments derived from basic, intermediate and acidic rockswere recognized. Paleovolcanic, neovolcanic, plutonic and metamorphic rocks weredifferentiated using their diagnostic textures. The cements identified are rim type clayceolithic and carbonatic, while the porosity is intergranular and by dissolution in feldespargrains, sustaining a shallow eodiagenesis. Petrographic results complemented withpaleocurrent measurements and regional geological data define possible provenance areas for the Santa Cruz Formation which are located 200 km northwest from the study area.Keywords: Petrography, source area, diagenesis