CONSIDERAÇÕES SOBRE TURBIDITOS DA FORMAÇÃO ITARARÉ (CARBONÍFERO SUPERIOR), RIO NEGRO - PR. e MAFRA - SC

Resumo

Some Upper Carboniferous turbidites of the Itararé Formation are described from outcrops in the States of Paraná and Santa Catarina (Brazil). Typical graded sequences, as well as other primary sedimentary features such as flute casts, convolute bedding, microcross-lamination, groove casts, and other sole markings, are briefly discussed. The origin of the turbidity currents, in that formation, is directly related to glacial activity. Thus, it is the Authors' opinion that the meltwaters of the Late Carboniferous ice sheets provided the density currents, responsible for the rhytmic deposits and their associated structures. Directional properties of these structures show a general NNE-SSW or NE-SW trend, but definite results require further studies and additional data. Even though the interpretation given in this paper for the direction of transport, in the Rio Negro-Mafra region, differs from that of other authors, the above mentioned results generally agree with those of the latter ones (Leinz, Maack, Martin). More detailed data are being gathered, and shall be given by the present writers in further papers concerning the Gondwanic turbidites of Southern Brazil.