O supergrupo Roraima ao longo da faixa fronteiriça entre Brasil e Venezuela (Santa Elena de Uairén – Monte Roraima)

Abstract

The geological knowledge about the stratigraphy of Roraima Supergroup is based on the last three decades. Its evolution has begun along the Paleoproterozoic (Orosirian Period), culminating with the largest continuous Pacaraima Sedimentary Block. At Brazilian portion the unit is related to Roraima Supergroup, divided from the base (oldest) upward into Arai Formation, Suapi Group (Uiramutã Formation at the base, Verde, Pauré, Nicarã and Quinô on top), Uailã Formation and Matauí Formation. In Venezuela represents Roraima Group, divided into Uairén, Cuquenán, Uaimapué and Matauí formations. Where the results are available, a correlation is made between both successions. The presence of several basic sills in different horizons constitutes an excellent stratigraphy marker. A Mesozoic dyke with strikes N-S and NNE-SSW is present. It’s expanded the terminology “Roraima Supergroup” to Venezuela portion, in attention to hierarchic order of its subdivision and type sections.