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A região da fronteira entre Brasil (municípios de Santana do Livramento e Quaraí, no Rio Grande do Sul), Uruguai e Argentina contempla grande geodiversidade. No território brasileiro, é possível visitar importantes geossítios situados no contexto da Bacia do Paraná. A geodiversidade dessa fronteira é pouco divulgada em publicações científicas. Entretanto, a região é retratada em diversas obras literárias que correlacionam as tradições de sua população com os monumentos naturais. Este estudo consiste na divulgação de uma rota geoturística para essa região, considerando os seguintes objetivos: divulgar sua diversidade geológica para o público em geral; e promover o geoturismo e a geoconservação por meio de um roteiro. Este inicia-se no Cerro Palomas (Santana do Livramento), onde os visitantes podem contemplar o relevo da região, composto de morros testemunhos formados por arenitos. A área do entorno desse cerro é formada por rochas sedimentares que contêm pegadas de dinossauros. Quando se parte em direção ao Cerro do Jarau (Quaraí/RS), ao longo do trajeto ocorrem diversos geossítios formados por rochas vulcânicas. Ao fim do roteiro, encontra-se o cerro em si, que é composto de rochas sedimentares e vulcânicas. Sua forma circular, associada a minerais formados em crateras de impacto, demonstra que essa estrutura corresponde a um astroblema. A elaboração e divulgação desse roteiro pode auxiliar nas medidas de implantação e potencialização do geoturismo, além de incentivar a geoconservação, fortalecer a divulgação da geodiversidade e da cultura regional.

Situated on the northern coast of the Rio Grande do Sul state, in the southern region of Brazil, the Torres municipality contains beautiful landscapes, with a variety of natural sights such as great dunes, lagoons, and its famous volcanic rock natural towers. The main geological processes that sculpted this region are associated with wind activity and the numerous rises and falls of the sea level that occurred between the Pleistocene to the present day. Torres is a highly popular tourist beach, and sees its population grow by nearly 500% during the summer months. Due to it being a tourism hotspot and its incredible geodiversity, Torres is one of the main areas of the “Caminhos dos Cânions do Sul” Geopark (CCSG), a 2,830 km2 area that encompasses seven municipalities situated at the boundary of the Rio Grande do Sul and Santa Catarina states. The geopark has three pillars, education, geoconservation, and tourism, and it aims to boost the economic, sociocultural, and environmental growth of the region in a sustainable manner. The geopark also seeks to help in the preservation of geological sites that most represent its regional diversity, such as the great Juro-Cretaceous volcano-sedimentary rock towers that give the city of Torres its name (which translates from the Portuguese to “Towers”). These structures, which can be seen throughout Torres’ coastline, are composed mostly of the basalts of the Serra Geral Group, which overlay the sandstones of the Botucatu paleodesert. In this municipality, the CCSG has, through lectures, itinerant exhibitions, training courses, and participation in cultural and scientific events, helped increase public consciousness regarding the importance of preserving and valorizing the area's geoheritage. In this work, we present a project developed through a partnership involving the Torres prefecture, the CCSG, and the GeoRoteiros group, which has as its objective the installation of information plaques about the geological evolution of the “Morros Testemunhos” and the state's Coastal Plain. We plan to install 10 plaques throughout the beach, each displaying didactic images and texts in an accessible language for the general public. The information available on these plaques will be summarized; in case the reader wishes to learn more, a QR Code will be available to take them to the websites of the organizing institutions, where they can not only read additional information, but also watch videos discussing the geosites of the geopark. This is a pilot project which will ascertain the viability of developing similar projects for the other municipalities that compose the CCSG.

This study reports a set of primeval marine incursions identified in two drill cores, 1PS-06-CE, and 1PS-10-CE, which recovered the Barbalha Formation, Araripe Basin, Brazil. Based on a multi-proxy approach involving stratigraphy, microbiofacies, ichnofossils, and microfossils, three short-lived marine incursions were identified, designated Araripe Marine Incursions (AMI) 1–3. AMI-1 and AMI-2, which occur within the shales of the Batateira Beds (lower part of the Barbalha Formation), were identified by the occurrence of benthonic foraminifera, calcareous nannofossils, dinocysts, and a mass mortality event of non-marine ostracods. AMI-3 was recognized in the upper part of the Barbalha Formation, based on the occurrence of ichnofossils and planktonic foraminifera. The observation of the planktonic foraminifera genus Leupoldina for the first time in the basin indicates early Aptian/early late Aptian age for these deposits, and the first opportunity of correlation with global foraminifera biozonation. Our findings have implications for the breakup of the Gondwana Supercontinent, as these incursions represent the earliest marine-derived flooding events in the inland basins of northeastern Brazil.

The Aptian–Albian interval is characterized by significant paleoclimatic, paleoceanographic, and paleogeographic changes, which in turn affected the distribution and evolution of marine ecosystems. Despite the importance of such studies, there have been few correlations between Aptian–Albian sections of the Tethys Sea and those of the South Atlantic Ocean. This interval, including the Aptian–Albian transition, is preserved in the deposits of the Riachuelo Formation (Sergipe–Alagoas Basin, Brazil) located in the South Atlantic Ocean; therefore, this location was chosen for drilling four new cores. The goals of this paper are as follows: (1) to explain the drilling operation carried out in the deposits of the Riachuelo Formation and the methods used; (2) to present a brief lithostratigraphic characterization of the holes and the paleomagnetic data of core SER-03; and (3) to describe the high potential of the cores recovered for additional investigation in the future. The lithostratigraphic units of the SER-01 core consist mainly of coarse- to fine-grained sandstone, shales, marls, and mudstones; the SER-02 core was excluded due to low recovery; the SER-03 core is mainly composed of fine-grained sediments (shale, marls, and packstone) and bears some ammonite shells; the lithology of core SER-04 is mainly sandstones. Magnetic susceptibility values (χlf and χhf) and frequency-dependent susceptibility (χfd) data suggest that the section is located within the Cretaceous Normal Superchron. Future studies on these cores integrating micropaleontological, paleoichnological, geochemical, stratigraphic, and paleomagnetic (e.g., relative intensity) data will allow for a better understanding of paleoceanographic and paleogeographic events related to the early evolution of the South Atlantic Ocean and how these events correlate to similar events in Tethyan sections.

This study reports a set of primeval marine incursions identified in the two drill cores (1PS-06-CE and 1PS-10-CE) recovering the Barbalha Formation, Araripe Basin, Brazil. Based on multi-proxy approach involving stratigraphy, microbiofacies, ichnofossils, and microfossils found in the Barbalha Formation, three short-lived marine incursions were identified, designated Araripe Marine Incursions (AMI). The AMI-1 and AMI-2, which occur within the shaly Batateira Beds (lower part of the Barbalha Formation), were identified through the occurrence of benthic foraminifera, calcareous nannofossils, dinocysts, and a mass mortality event of non-marine ostracods. The AMI-3 is recorded in the upper part of the Barbalha Formation and its identification was based on occurrence of ichnofossils and planktic foraminifers. The presence of planktic foraminifera genus Leupoldina suggests, for the first time in the basin, an early Aptian/early late Aptian age for the deposits and allows correlation of this unit with global foraminifera biozonation. Our findings have implications for the breakup of the Gondwana Supercontinent, as these incursions represent the earliest marine-derived flooding in the inland basins of Northeastern Brazil.

The Early Cretaceous was dominated by greenhouse conditions and increases in ocean crust production rate, with critical climate, geography and oceanography changes and abrupt shifts in redox conditions in the oceans. Prior to the Aptian, regarding the Earth’s magnetic field, a high rate of polarity reversals dominated. However, thereafter, a period of polarity stability, known as the Cretaceous Normal Polarity Superchron (CNPS), was established for 34 Myr. Although, there are debates on the causes and consequences of these extreme events. The exact behavior of the geomagnetic field in this period is still poorly understood, and data from volcanic and sedimentary rocks are conflicting. The biostratigraphy data from the sedimentary succession from the Aptian-Albian interval in the Sergipe-Alagoas Basin (Brazil) are rare and correlations are weak with Tethyan realm. Since some of the major reservoirs of the terrestrial portion of the Sergipe-Alagoas basin are from Aptian-Albian ages the lack of age models brings difficulties to the oil industry. Magnetic parameters such as magnetic susceptibility, ARM, IRM, and magnetostratigraphy data were obtained with a resolution of 25 cm in the Core SER-03 from Sergipe-Alagoas Basin. The entire section varies 4 Myr, including the Aptian-Albian boundary. Here, we present preliminary environmental magnetism and magnetostratigraphic interpretation for this core. Therefore, these data will aid to develop an age model framework in order to assist this uncovered region and for future comparisons with Tethyan realm.

This paper presents a biostratigraphic revision and a quantitative study of the calcareous nannofossils from DSDP Leg 80 – Hole 550B. A total of 42 samples were analyzed, revealing 78 species whose preservation varied from slightly to moderately dissolved with slight to severe overgrowth. Biostratigraphy indicates deposition during the late Campanian to late Maastrichtian, incorporating zones UC15d to UC20b. The quantitative nannofossil data recovered shows that Watznaueria barnesiae and Micula staurophora dominate the assemblages, which can be attributed to a low preservation potential for the depositional environment. Cold-water taxa ( Kamptnerius magnificus , Ahmuellerella octoradiata, and Arkhangelskiella cymbiformis ) are present in very low percentages, with their maximum values occurring inside the UC17 biozone.

The Albian–Cenomanian was an interval of extreme warmth due to greenhouse climatic conditions, as well as significant changes in the paleogeography and paleoceanography of the oceans, which affected the evolution of marine ecosystems on a global scale. This study analyzed the calcareous nannofossil assemblages from 72 samples that were recovered from Site 364 (Kwanza Basin, Angola), which was drilled by the Deep Sea Drilling Project (DSDP) Leg 40. A total of 103 calcareous nannofossil species were recovered, enabling the identification of biozones (CC 8 to CC 10a; or BC 23 to UC 1b/UC 4a) allowing to assign an Albian–Cenomanian interval for the deposition of the studied section. The recovered assemblages have a subtropical-tropical affinity and are indicative of a surface water connection between the Central Atlantic and the South Atlantic oceans, that extends at least as far as offshore Angola. The area sedimentation was predominantly calcareous and pelagic during this interval, with the exception of the basal section, where Albian black shales interbedded with dolomitic and marly limestones were deposited. Throughout the section, high concentrations of TOC and sulfur and the presence of dissolution-susceptible species likely indicate low euxinic conditions for the Kwanza Basin. Dissolution is a significant process for Site 364 in the majority of the studied samples, although not to the point where species richness was severely impacted, as small amounts of dissolution-susceptible taxa were observed. Dissolution showed a marked decrease in intervals in which paleontological and geochemical data indicated an increase in surface water fertility/productivity.

Brazil is a country of continental proportions, with enormous geological wealth and potential for new discoveries based on innovative research techniques. There are demands for the increase of knowledge on country’s geology. The 48 th Brazilian Congress of Geology (48 th BCG) will play an important role in bringing this knowledge together from academia, industry, professionals and society through courses, talks and discussions.