Primeira expedição científica à Serra de Paranapiacaba e ao Alto Ribeira

Resumo

The present article is and abridgment from the chapter "Physiography" comprehended at the last Tome from the Report elaborated by Coronel João de Mello Moraes and Major Sinval Pinehiro, both from the Army Geographic Service, that participate to the last Scientific Expedition to the "Paranapiacaba Sierra" and to "Alto Ribeira" (south region Paranaense) realized from January till April of 1956, under the auspices of the Board of Defense from Natural Patrimony of Paraná State.

            The authors, after defining the Geographic situation of the choosed area for acknowledgment and researches, which essence is the Corporation Town of Cêrro Alto, on Paraná State, so, they treat with display about Geology, Mineral Resources, Geomorphology and Pedology.

            In relation to Geology, they sketch a backwards from the Geological recognizances that, about the last 40 years, but with a solution of continuity, have been expanding in the Alto Ribeira Paranaense and they show the contribution that the Expedition of 1956, brought over, reuning through tracks, since then never thrashed before, neither by geologists from the Federal Government, or searchers from particular establishments.

            They describe the Mineral Richness from that Region, summoning the extraordinary concentration of mineral spring-waters, alkaline-roaster, calcium-magnesium, in Varzeão Town and reveal to have collected around 150 samples of rocks for analysis and description noticing among them, radioactive mineral and copper, opal and marble from the "travertino"' type.

            Practically the hole region of the Alto Ribeira unrolls in a geological formation belonging to the Açungui series, denomination crated by Orville Derby and included at the inferior algonquian.

            The Açungui series is the fallowing at the Paraná State, from the São Roque series that have. been described at São Paulo State, have been compared by some geologists to the Minas Gerais State to the Brusque and some others congenerous formations from the brazilian territory,

            The typical rocks from the Açungui series, are natives from Proterozoic sediments highly metamorphic that lie down on stratum or lenses, in due form, generally to the North East direction and with variable slopes.

            With predominance of "filitos", calcareous, quartzites and metamorphic "xistos"; few are the intrusions of basic magmas, on the contrary of what occurs with the acid magmas, remarkably granite-porphyry, which shows magnificent expositions in the Ribeira's bed-river on the running out of Ribeirão Bonsucesso and at the inferior course of Ponta Grossa and Turvo Rivers.

            The authors pointed out that the area drained by the basin of the Alto Ribeira, neither distinguish a landscape at the Paraná State, thanks to the rough relief, but also provides itself from enormous economical importance. in behalf of the great Mineral Resources.

            Among the minerals, metallical or not, which. constitute couches of industrial value, we may detach the barium oxide, with middle tenor of 63% of barium oxide; the silver lead glance which treatment gives to the Paraná State the position of the greater producer of lead and silver in Brazil, as well as comming just after Minas Gerais State, on gold mining; copper minerals, with tenor of metallic copper of 6% to 15%; calcareous to all things: cement lime and spice we can find at all speed, on that raw-material zone, a plant with two furnaces, producing more than 200.000 sacks of cement-a-month.

            The authors appreciate the beauty of the ornamental rocks from the Alto Ribeira, making a special mention to the variety and abundance of marbles, some of them considerated as Carrara, Calacati, Extremós, Branco Nuria and Travertino Types.

            The authors claimed for themselves, the discovery of the first opal couch into the Brazilian territory, because, since then, Opal has been founded in Brazil, as small fragments, scattered.

            Another important report, they made, was to have determined in "trigonometric system" the point of culmination from the rocks of the algonquian system, at the Paraná State, founding it the quartzites which form the Bocaina Peak ·at the altitude of 1503 metres, situated at 20 km. of the Bocaiuva do Sul Town.

            The relief, which with no doubts the authors considers the top of the regional landscape, is the purpose of an accurate study being classified in different groups, subordinated to the nature of the rocks in which has been molded.

            The authors demonstrate that the prominence of the quartzites structure, commands altimetrically the whole relief of the Alto Ribeira Paranaense, with imposing stratum hillocks (hogbacks) revested on top by alpine fields.

            They continue with some considerations about the relief, notably dissected, that characterize, in conjunct, the region drained by the Alto Ribeira, showing deep valleys in V shape, which ones, nevertheless, have not constitute an obstacle to the customary agriculture and to the extrative timber industry, conveying serious problems to soil maintenance.

            We can find into the richer potamographic net of the Alto Ribeira, many waterfalls, been the construction of dams to hydroelectric ends, so much favorable by the disposal of the relief. ·

            Ending the First Volume, of this Report, it appears the study of the regional pedagogical conditions, with the contribution of the pedologist from the Expedition, Professor Wladimir P. Kavalebidze, author of the "Chart of the Moroccan Solis", presenting conclusions of practical order, about the conservation of the mountain soils and summoning the cultures mioncecally more favorable.