Sedimenta????o mista carbonato-silicicl??stico durante o albo-aptiano na por????o emersa da bacia Sergipe-Alagoas

A se????o mista analisada, de idade Albo-aptiana e formada por constituintes carbon??ticos e silicicl??sticos, aflora na por????o emersa da Bacia de Sergipe-Alagoas, pr??ximo ?? sua borda atual. Os afloramentos se localizam 50 km a noroeste de Aracaju e, em sua maior parte, se situam em loca????es de po??os de petr??leo. As interpreta????es ora apresentadas foram baseadas em dados de afloramentos, perfis de georadar, perfis el??tricos de po??os, dados litol??gicos de po??os, se????es delgadas, mapas de is??litas e se????es estratigr??ficas. A sucess??o ?? composta por dep??sitos de leques deltaicos, litor??neos dominados por ondas (sedimentos mistos) e de rampa carbon??tica. No caso dos leques deltaicos, as f??cies proximais (plan??cie deltaica) s??o dominadas por barras longitudinais areno-conglomer??ticas e, secundariamente, de fluxo de detritos. Sua por????o subaquosa ?? representada por acumula????es em ??reas protegidas (e.g. ba??as). Na por????o proximal (frente deltaica) ?? constitu??da por conglomerados, arenitos e, secundariamente, siltitos aThe 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 gra