Felipe Caron

Megaichnus igen. nov.: Giant Paleoburrows Attributed to Extinct Cenozoic Mammals from South America

ABSTRACT In the last ten years, more than 1,500 large burrows have been discovered in southern and southeastern Brazil, dug in rocks that include weathered granitic and basaltic rocks, sandstones, and other consolidated sediments. Their presence in geological units of Plio-Pleistocene age suggests that large extinct mammals produced these structures. The internal walls exhibit scratches and grooves left by the animals that inhabited these structures. The burrows are straight or slightly sinuous tunnels that measure up to tens of meters in length. One smaller type measures up to 1.5 meter in diameter, and the larger type can reach 2 meters in height and 4 meters in width, suggesting that such structures have been produced by at least two kinds of organisms. This contribution proposes a classification for these ichnofossils under the generic designation Megaichnus igen. nov., consisting of two ichnospecies identified so far: M. major and M. minor ispp. nov. Although the exact identity of the producers of the burrows is yet unknown, the dimensions and morphology point to ground sloths and giant armadillos.

Geomorfologia e arquitetura deposicional de uma planície de cordões litorâneos na margem NE da Lagoa dos Quadros, RS, Brasil

Foredune ridges and beach ridges are morphological elements largely present in coastal lakes and coastal lagoons. However, it still requires further studies. This paper presents results of a prograding strandplain (sand ridge plain) developed at the NE margin of Quadros Lagoon, in the northern littoral of Rio Grande do Sul. Aerial photographs analysis, topographic surveying, GPR records, soundings and surface samples allowed to study the morphology of the strandplain and the stratigraphic framework of their respective sedimentary deposits. The strandplain comprises 20 continuous and semi-continuous ridges, of low amplitude and spaced 5 to 50 m. A regressive sequence comprising deposits of shoreface, backshore/beachface, foredunes and washover fans was developed aggradacionaly and proggradacionaly over a basal facies of a lagoon bottom, between the last 7 to 6 ky. Transgressive dunefields from the Holocene barrier IV (Curumim barrier) to Quadros Lagoon was probably an important source of sand for the strandplain development.

CARACTERIZAÇÃO DOS REJEITOS DAS MINAS DO CAMAQUÃ PARA REAPROVEITAMENTO SUSTENTÁVEL

The reuse of waste stemmed from mining activities is extreme important because it is a possible polluters of the environment. This work coverd sustainable social and economic waste reuse remainder of ore copper processing from the Minas do Camaqua. In the first phase of the study were employed: sampling methodologies, particle size separation, physical-chemical analyzes, mineralogical analysis, physical and chemical tests concentration of minerals, iso-contour map elaboration of contents to director element, the copper. In the second phase the particle size analysis detailed the percentage of fine distribution, classification of waste according to ABNT 10004 and evaluation of economic pre-viability to verify recovery alternative of copper through leaching method and test for using of the material in contruction. In conclusion, the economic recovery of copper by leaching is impossible, according to economic analysis model. The technical pre-viability of use in brick factory, was found as results of the simulations in testing done of the agreement with an industrial manufacturing and quality index standards (NBR 8492). The residue, it performed inert of the agreement with ABNT 10004 and fine sand grain size between even very fine sand.