Terrestrial impact structures as geoheritage: an assessment method of their scientific value and its application to Brazil

Terrestrial impact structures are geological and geomorphological features with particular importance to understand the history and evolution of the planet. Impact structures are scattered around the world but in many countries these features are under threat, essentially due to anthropic factors. Impact structures with higher scienti c value should be considered as geological heritage and, consequently, be subjected to geoconservation strategies. In order to select the most important impact structures to be properly conserved and managed, this paper proposes a quantitative assessment method of the scienti c value of these structures. The eight Brazilian impact structures were used to test this method that has the potential to be applied to any geological context in any country. The structures known as Araguainha Dome-MT and Serra da Cangalha-TO reached a higher scienti c value, which justi es the need to develop geoconservation strategies and a proper management.The Conselho Nacional de Pesquisa e Desenvolvimento (CNPq / National Council for Research and Development) and the Programa Ciências sem Fronteiras / Science Without Borders Programme are acknowledged for the support of the postdoctoral grant No 233209/2013-1 of the 1st author. The work was co-funded by the European Union through the European Regional Development Fund, based on COMPETE 2020 (Programa Operacional da Competitividade e Internacionalização), project ICT (UID/ GEO/04683/2013) with reference POCI-01-0145- FEDER-007690 and Portuguese funds provided by Fundação para a Ciência e Tecnologia.info:eu-repo/semantics/publishedVersio

Calibrando la transición ediacárico-cámbrica en Gondwana suddoccidental

The paleontological, isotopic and geochronological data summarized below support the paleogeographic and temporal correlation between Itapucumi (Paraguay) and Corumbá (Brazil) groups, suggesting a coeval sedimentary evolution of these units in the margins of the Amazon Craton and the Rio Apa Block.Los datos paleontológicos, isotópicos y geocronológicos que se resumen a continuación apoyan la correlación paleogeográfica y cronológica entre los Grupos de Itapucumi (Paraguay) y Corumbá (Brasil), sugiriendo una evolución sedimentaria contemporánea entre estas unidades en los márgenes del Cratón Amazónico y del Bloque del Río Apa

Permian-Triassic maturation and multistage migration of hydrocarbons in the Assistência Formation (Irati Subgroup), Paraná Basin, Brazil: implications for the exploration model

New lines of geological evidence strongly suggest that the main period of hydrocarbon maturation within Assistência Formation should be Permian-Triassic, stimulated by a high geothermal gradient that also sustained various manifestations of hydrothermal activity. Three main stages of fluid/hydrocarbon migration can also be inferred on the basis of multiscale observations: confined flow in late Permian to Triassic times, depending on the local build-up of fluid pressures; heterogeneous flow in Lower Cretaceous, triggered by a rejuvenated temperature gradient assisted by the early developed permeability conditions; and a late flow possibly driven by local pressure gradients, after complete cooling of dolerite dykes/sills. The early maturation and multistage migration of hydrocarbons have significant consequences in the design of exploration models to be applied in Paraná Basin