Showing papers in "Journal of South American Earth Sciences in 2013"

TL;DR: In this paper, it was shown that the Embu terrane is the continuation of the Socorro-Guaxupe Nappe and therefore also part of the active margin of the Paranapanema paleocontinent.

TL;DR: A set of contour maps of the seismic structure of South America and the surrounding ocean basins is presented in this article. But the authors do not provide a detailed analysis of these maps.

TL;DR: In this paper, a compilation of data from deep seismic refraction experiments, receiver function analyses, and surface-wave dispersion velocities was used to estimate the crustal thickness of Brazil and adjacent areas.

TL;DR: In this paper, the authors analyzed the relationship between spectral reflectance and the surface suspended sediment concentration (SSSC) using both field radiometric measurements and satellite data, which provided evidence of significant sedimentation and resuspension.

TL;DR: In this paper, the results of the analysis of new materials recovered from different levels of the Monte Hermoso Formation, following a strict control of stratigraphic provenance, are reported.

TL;DR: In this article, two large domains with distinct evolutionary histories are identified with respect to the Neoproterozoic era: the northwest-west (Amazonian craton and surroundings) and the central-southeast (the extra-Amazonian domain).

TL;DR: In this article, the authors examined the mantle sources involved in the high-Ti (Pitanga and Paranapanema) basalt genesis, and studied Sr, Nd and Pb isotopic systematics, and major, minor and incompatible trace element abundances.

TL;DR: The Archean granites exposed in the Mesorchean Rio Maria granite-greenstone terrane (RMGGT), southeastern Amazonian craton can be divided into three groups on the basis of petrographic and geochemical data as discussed by the authors.

TL;DR: Palynological and stratigraphical analyses were carried out on the outcrops of the Solimoes River to present new information about freshwater paleoenvironments of a fluvial-deltaic and meandering river system, evaluate the vegetation changes in the upper solimoes and Ica Formations, and the role of the Purus Arc in the evolution of central Amazon during the upper Neogene as mentioned in this paper.

TL;DR: In this paper, the authors use the latest Earth Gravity Model derived from the observations of the GOCE satellite mission, to retrieve the gravity anomaly and correct it for topographic effects, thus obtaining the Bouguer field.

TL;DR: A thorough petrographic, geochemical, isotopic (Sr and Nd) and geochronological (UePb SHRIMP) study is reported in this article.

TL;DR: In this article, an evolutionary model for a coastal barrier in the southernmost coastal sector of Brazil during the Holocene was presented, based on 15-20m drill cores and ground-penetrating radar (GPR) records.

TL;DR: In this article, the authors revisited five examples from north to south, which demonstrate that, the Andes and the distal forelands have been uncompensated since the beginning of the Cenozoic and that additional forces, such as mantle downwellings and upwellings, are required to account for the observed topographies in basins and elevations.

TL;DR: In this article, the authors analyzed the connectivity elements and processes controlling riparian vegetation for a reach of the upper Parana River (Brazil) and estimated the future changes in channel-vegetation relationship as a consequence of the managing of a large dam.

TL;DR: The morphology and sediment dynamics of the 1500-km-long coast of South America between the mouths of the Amazon and the Orinoco Rivers are largely dependent on the massive suspended-sediment discharge of the Brazil coast, part of which is transported alongshore as mud banks as discussed by the authors.

TL;DR: In this paper, the isotope systematics and the magmatotectonic history of mainly Cenozoic igneous rocks from Italy shows them to be inconsistent with subduction-related magmatism.

TL;DR: The ORE-Hybam (IRD-SENAMHI-UNALM) observatory has performed regular measurements at strategic points of the Amazon basin to understand and model the systems, behavior and long-term dynamics as discussed by the authors.

TL;DR: Rocha-Campos et al. as discussed by the authors used SHRIMP radiogenic isotope dating on zircons in tuffs (280.8±1.9 Ma) to confirm the Early Permian (Artinskian) age of the uppermost section of the Tunas Formation.

TL;DR: The relationship between basic aspects, such as the vegetation and geomorphology of the Parana River floodplain, has scarcely been investigated as discussed by the authors, and the annual dynamics of vegetation in relation to the geomorphologic and hydrological characteristics of a river floodplain around 31° 30′ S, are analyzed.

TL;DR: In this paper, the authors revisited outcrops in the Taubate and Resende basins and have reinterpreted 11 seismic profiles of the Tertiary basins.

TL;DR: A new middle Miocene vertebrate fauna from Peruvian Amazonia is described in this article, yielding the marsupials Sipalocyon sp. (Hathliacynidae) and Marmosa (Micoureus) cf. (Erethizontidae), as well as an unidentified glyptodontine xenarthran and the rodents Guiomys sp.

TL;DR: The Pelotas batholith is composed of seven granitic suites with minor occurrences of gabbro, diorite and subvolcanic rocks as discussed by the authors, which were formed by syn-kinematic conditions during a transcurrent event.

TL;DR: In this paper, the authors show that among the combined impact of all parameters (climate, runoff, slopes, vegetation...), the basins age seems to be the control parameter on chemical weathering and land use: the younger the basin, the higher the weathering rates.

TL;DR: In this article, a set of recently published data for the Sierras Pampeanas in central and northwestern Argentina, which constitutes a distinct morphotectonic feature between 27°S and 33°S, was reviewed.

TL;DR: The chondrichthyan fauna of the early Miocene Culebra Formation of Panama provides insight into the marine vertebrates occupying shallow seas adjacent to the Central American Seaway, prior to the rise of the Isthmus of Panama.

TL;DR: In this article, radiometric U-Pb ages obtained on zircon crystals from Early Jurassic ash layers found within beds of the Chachil Limestone at its type locality at Chacay Melehue (southern Neuquen Basin) confirm a Pliensbachian age (186.0 ± 0.4

TL;DR: The Baquero Group is one of the most relevant units regarding the study of the early diversification of angiosperms in South America and has been recently dated at 118.23 ± 0.09 ǫ for a tuff interlayered with fossiliferous rocks of the Anfiteatro de Tico Formation as mentioned in this paper.

TL;DR: In this paper, the authors address general features of carbonatite monogenetic volcanic fields located in continental settings which are peculiar being associated with kamafugites or melilite-bearing leucitites.

TL;DR: It is demonstrated that some endemic, “brackish” water ostracods have been effectively adapted to freshwater conditions, and there is no univocal evidence for the influence of brackish or marine waters in western Amazonia during the Miocene.

TL;DR: In this article, the interpretation of the record according to new criteria of ontogenetic change has demonstrated that they are useful for biocorrelation because their members have short biochrons with wide geographic distribution.