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Ice age mass-transport deposits (MTD) occur in multiple stratigraphic intervals within the Permocarboniferous Itararé Group, in the Paraná Basin, and are exposed in several disconnected quarries and road cuts around the region of Mafra, southern Brazil. The most typical deposits are diamictites with muddy matrix, but silty-sandy diamictites and metric intercalations of deformed layers of sandstones and siltstones occur subordinately. Similar MTD facies have been described from better exposed and time equivalent successions in western Argentina. There, because of the km-scale exposures, MTDs can be mapped in their plenitude, giving better insights about their emplacement. In this paper, we describe the Brazilian MTDs and infer their modes of transport and deposition supported by comparisons with published Argentinean examples. Based on matrix constitution, presence of coherent blocks and rafts, and sedimentation phases, at least four types of MTDs can be identified: 1) Mud-rich MTD and isolated sandstone blocks; 2) Resedimented MTD represented by diamictites with folded blocks of diamictite, possibly corresponding to two phases of remobilization; 3) Sand/silt-rich MTD (evolved stage), and formed by deformed bands of sandstones and siltstones (mature stage); and 4) MTD with rafts of heteroliths and sandstone blocks. Usually MTDs rest on and scour into a fine-grained substrate such as thin-bedded turbidites and shale. The regional geological setting at Mafra points to an open embayment. The collapse of inclined depositional slopes related to high sediment supply associated with deglaciation was the major control on MTD development. However, the inferred proximity of the ice margin during slope failure was variable, suggesting MTD formation during different stages of a glacial cycle. • MTDs occur in different stratigraphic positions in Itararé Group during the LPIA. • The constitution of the MTD depends on the protolith and stage of evolution. • Comparing Paganzo with Mafra added knowledge about LPIA Mass Transport Deposits. [ABSTRACT FROM AUTHOR]

Apart from Vaca Muerta's case history in Argentina, the unconventional exploration in South America is still underdeveloped, and one of the causes is the scarcity of geological studies. The present paper enlightens the embryonic unconventional exploration in the Sergipe-Alagoas Basin by introducing a seismic interpretation workflow to map thin shale layers and the natural fracture system, a challenge in unconventional reservoir explorations. Fracture and faults are critical elements in exploring ultra-low permeability shale oil/gas reservoirs. Identifying and locating these structures influence modeling fluid flow, hydraulics, and simulation models to improve horizontal well-drilling plans. The workflow comprises four main steps: data pre-conditioning, well-to-seismic tie, seismic spectral blueing (for frequency enhancement), and, finally, spectral decomposition and advanced fault attributes. The proposed workflow was applied to a seismic dataset from the onshore Brejo Grande oilfield focusing on the source rocks of the Coqueiro Seco Formation, the main unconventional reservoir candidate in the basin. That approach allowed mapping the lateral continuity, truncation, faults, and fractures in these thin shale layers previously below seismic resolution. The mapped structures belong to the complex natural fracture system with faults distributed to all trend directions. These faults are distributed along two zones with distinct fault densities with a possible sweet spot outline. • We present an interpretation workflow implemented to unconventional reservoirs. • The workflow combines seismic-resolution enhancing techniques and fault attributes. • As a result, thin-shale layers and fault zones were identified at Coqueiro Seco Fm. [ABSTRACT FROM AUTHOR]

The red crab Chaceon notialis is endemic to the Southwestern Atlantic (Brazil, Uruguay and Argentina), occurring from 200 to 1600 m deep. The species belongs to the Geryonidae family and exhibits a K-strategist life cycle. Due to its increased exploitation over recent decades, this marine resource requires attention regarding its conservation and management. In this work, were analyzed red crab populations from the three countries that cover the species' entire distribution range, assessing diversity and differentiation through morphometric and genetic analyses. The evaluated morphometric measurements were length and width of the carapace; length, width and height of the chelae propodus; and female abdomen width. For genetic evaluation, the following mitochondrial DNA regions were used: the partial 12S gene and the entire Control Region (861 bp); and the partial Cytochrome c oxidase subunit I (1252 bp). The morphometric results showed two distinct phenotypic groups (one from Brazil/Uruguay and the other from Argentina), with significant differences in female abdomen width and chela size. Genetic analyses, however, revealed only a single panmictic population, with no genetic structuring among the analyzed stocks. These findings suggest that the management measures applied in each country will influence the population dynamics of the others, and that international cooperation is necessary for achieving sustainable fisheries of this valuable resource. Since commercial fishing of the red crab C. notialis is not conducted in Argentina, we propose that this area can act as a biological reserve for this species. Due to the commercial importance of this crab, knowledge of the species' diversity is of fundamental importance for its management, conservation, and to provide baselines for future biological and ecological studies. • Morphometric analyses identified two morphologically distinct red crab groups. • Chelae size and abdomen width are the main characteristics that separated groups. • Molecular analyses (mtDNA) identified a single panmictic population. • Planktonic larval distribution may influence the lack of genetic structure. • A coordinate fishery management between countries is suggested. [ABSTRACT FROM AUTHOR]