Sedimentação mista carbonato-siliciclástico durante o albo-aptiano na porção emersa da bacia Sergipe-Alagoas

Abstract

The Albian-Aptian mixed sediments, composed of carbonate and siliciclastic constituents, occur in the onshore portion of the Sergipe-Alagoas Basin, next to its current border. Outcrops are located 50 km to northwest from Aracaju and, for the greater part, in oil well areas. The interpretations now presented are based on outcrop description, georadar sections, electric well logs, well litology data, thin sections, isolith maps and stratigraphic sections. The succession is composed of fan delta deposits, wave dominated coastal sediments (mixed sediments) and carbonate ramp. In relation to the fan delta, the proximal facies (delta plain) are dominated by sandy-graveley longitudinal bars and secondarily by debris flow deposits. The sub-aqueous portion is represented by accumulations in protected areas (e.g. bays). The delta front is constituted of conglomerates, sandstones and secondarily siltites associated with gravitational flows and trative flows, eventually reworked by waves. Delta front distal deposits grad