Geologia, petrologia e geomorfologia da Ilha de São Francisco do Sul

Resumo

            This article, in which the author spent several years in the fíeld work, it was studied the geology, the petrology and the geomorphology of the "Ilha de São Francisco do Sul" in St. Catarina's coast.

            After locating geographically the observed region and making a brief digression about its geological aspect, he proceeds and affirms that the mentioned region consists of archeozoíc rocks, nevertheless he asserts the possibility of being proteozoic or algoquain.

            With reference to the geomorphology, after situating the "Rio São Francisco" bay in the class of the ingression bay, for the author accepts that it has been risen to higher levels than the existing today, wíth posterior alternate transgressive and regressive movements, he concludes that those levels are typical, so they are named "sanfranciscanos", however there is a similar occurrency in the border zone between "Paraná" and "São Paulo" and in another spots of the brazilian coast.

            On the point of view petrographic, the author analyzes the texture, the composition and the microscopic characters of various kind of rock, after that he ponders about the origin and the evolution of these elements.

            Dr AXEL LOEFGREN from Map's Archive and Geologic Charts Section contributed to the elaboration of this work, as well as Dr EVARISTO PENA SCORZA helped out as chief of Petrography Section of Rio de Janeiro, who was in charge of the description of the collected material.