Efeito termal de intrusões básicas cenozóicas em rochas carbonáticas da formação Jandaíra, Bacia Potiguar - RN

Abstract

The Potiguar Basin, located in the extreme NE of Brazil, in the Agreste Potiguar mesoregion, has an expressive volume of basic intrusive bodies related to the Meso-Cenozoic magmatism: Rio Ceará Mirim, Serra do Cuó and Macau. The study area is about 122 km from Natal-RN, located between the municipalities of Jandaíra and Pedro Avelino, in the State of Rio Grande do Norte. The present work proposes to study the thermal effect caused by the basic plug of the Nova Conquista settlement in the limestone encasing rocks of the Jandaíra Formation, which emerges from the Potiguar Basin, in terms of the petrography and textures of the rocks that occur around the thermal aureole. The thermal effects had their extension inferred through contact relations in metric to decametric scale, however such extension can be better defined in more detailed petrophysical studies. In sandstones, such effects were summarized in the generation of glassy texture and pyrometamorphic minerals; the thermal effects described in limestone were thermal recrystallization, formation of granoblastic texture and destruction of microfossils, as well as reductions in the porosity and permeability of these limestones.