CONTRIBUIÇÃO À GEOLOGIA DO MUNICÍPIO DE CERQUILHO, SP

Abstract

This paper is a contribution to the geology of the Cerquilho county (125 km2), state of São Paulo, Brazil, which is located at the center-east of the state, 160km from the city of São Paulo. The main purpose of this research was to get geologic and lithologic maps of the area, at a 1:50.000 scale, as a contribution to a better understanding of ground water distribution. Water from wellsis urgently needed to the municipality supply. Late Carboniferous to Permian 550m thick Itararé Formation is the main stratigraphic unity in extension and in thickness. Less developed are the Permian Tatuí and Irati formations. Latest Jurassic to Earliest Cretaceous tholeitic diabase intrusions, as dyke and sills cut these formations. Along some of the river valleys developed narrow alluvial deposits. The main lithologies of the ltararé Formation are diamictites (some true tillites), sandstones and siltstones. They are highly variable in distribution, interfengering each other vertically and horizontally. Coal seams are distributed mostly in the upper beds of this formation.