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Fossils from natural tanks can contribute to the paleoenvironmental interpretation of the Brazilian Intertropical Region (BIR), an important study area for the Quaternary in South America. In this paper we present results of δ13C and δ18O for Eremotherium laurillardi (δ13C = −4.6 ‰, δ18O = 33.0 ‰), Toxodon platensis (δ13C = −3.8 ‰, δ18O = 35.5 ‰), and Notiomastodon platensis (δ13C = −2.9 ‰, δ18O = 31.6 ‰) from Zabelê tank, compared to other localities, suggesting that these taxa had a mixed-feeder diet with a higher consumption of C 4 plants (p i > 60%), living in a transition zone between woodland savannah and open savannah. The Zabelê tank, northeastern Brazil, presents Optically Stimulated Luminescence ages ranging from 41.2 to 30.4 ky (Lujanian Stage/Age; Late Pleistocene). The origin of the fossiliferous layer through debris flow suggests short periods of intense rainfall under drier climatic conditions. Compared to other locations in the BIR, Zabelê documented a drier climate (δ18O = 31.6–33.4 ‰), which preceded the last glacial maximum. These new isotopic data to OSL ages associated with previous data from the BIR contribute to the understanding of the paleoecology and paleoenvironment dynamics of South America. • New δ13C and δ18O for the three most studied taxa from the Quaternary of the BIR. • These taxa had a mixed-feeder diet with higher consumption of C 4 grasses. • These taxa inhabited a transition zone between arboreal to open savanna. [ABSTRACT FROM AUTHOR]

An approach involving data on wave-induced sediment transport estimates is essential for managing coastal environments. Numerical models are powerful tools to understand and investigate many processes responsible for longshore sediment transport (LST) in a systematic way, since direct measurement of LST is a difficult task. This paper presents estimates of longshore sediment transport through numerical modeling of wave-induced sediment dispersion patterns in the Formosa Bay, State of Rio de Janeiro - Southeast Brazil. The analysis was conducted using the computational package Coastal Modeling System/SMC-Brazil and mathematical formulations proposed by Cerc (1984). The results suggest average residual solid discharge (Qsr avg) in the order of 131,442.745 m3/yr in northern sector, −151,908.32 m3/yr in central sector, and 71,987.69 m3/yr in southern sector of investigated area. In addition, it is important to highlight that minor variations in the wave incidence angle may cause changes in the longshore sediment drift, promoting the convergence and divergence zones throughout the investigated area. The results presented contribute to the advancement of knowledge on the topic addressed here and will be useful in future engineering projects related to beach nourishment and the management of coastal areas subject to erosion processes. • Data are presented on simulations of wave-induced longshore sediment transport rates in Baia Formosa Bay, southeastern Brazil. • The Coastal Modeling System SMC/Brazil were used. • Results suggest different solid outflow rates for each sector of investigated area. • The model may provide a basis for planning actions and environmental management in coastal zones. [ABSTRACT FROM AUTHOR]

This work presents facies analysis of pyroclastic and effusive deposits present in areas of the Fernando de Noronha Archipelago (FNA), South Atlantic Ocean. A detailed stratigraphic study was carried out for the Remédios Formation at the Caieira beach and the Quixaba Formation at the Capim-Açu Edge, Americano, and Bode beaches. The lithofacies association for the deposits of the Remédios Formation characterizes non-welded ignimbrites of phonolitic composition generated by concentrated ground-hugging density currents originated from collapses of a buoyant eruption column. Possibly, this phase was followed by a caldera collapse and the exposition of a complex system of dikes at Caieira Beach. For the deposits of the Quixaba Formation, the lithofacies association characterizes scoria and ash flow/grain avalanching deposits, proximal fallout deposits, and Pahoehoe lava flows. The Quixaba volcanism shows evidence of pulses of Strombolian and possibly Violent Strombolian activity alternated with effusive Hawaiian activity. A later stage of magma-water interaction during the Quixaba volcanism led to the formation of a sustained eruption column and fallout deposits with ash aggregates formed through wet aggregation. This paper is the first ever written about aspects of the Physical volcanology of the Fernando de Noronha Archipelago, Brazil. It contributes to the understanding of the evolution of the volcanism that occurred in the Archipelago between ∼12 and ∼1.2 Ma, and of the South Atlantic Ocean. The conclusions of our study are: The stratigraphic study of specific areas of the Archipelago through field observations complemented with laboratory-based pyroclastic and lava flow descriptions allowed us to propose the following evolutionary model: • Explosive magmatic eruptions formed buoyant eruption columns that collapsed and originated ground-hugging concentrated density currents represented by the lithic-rich non-welded ignimbrites. • Volcanic and subvolcanic manifestations generated domes of phonolitic and trachytic composition; i) and ii) might be concurrent. Possibly this phase was followed by a caldera collapse with the exposition of a complex system of dikes at Caieira Beach. • A hiatus in the geological record of about 3 Ma, characterized as a period of quiescence and erosion. • Effusive Hawaiian eruptions with the emplacement of olivine nephelinitic pahoehoe lava flows. Alternated to the effusive eruptions, Strombolian and possibly Violent Strombolian pulses led to mass ejections of juvenile ash, lapilli, bombs, and cognate lithic fragments, forming grain-avalanching scoria deposits, and scoria-and-ash flow deposits. • Stage of dominant water-magma interaction and the formation of a water-rich volcanic cloud, which led to the formation of planar-stratified bedforms, fall-dominated with mixed deposition of ash aggregates in the shape of massive ash pellets, layered and complexly layered accretionary ash pellets, armored and complexly layered armored ash pellets, formed through wet aggregation. [ABSTRACT FROM AUTHOR]

Climate change has increased the frequency of extreme weather events and, consequently, the number of occurrences of natural disasters. In Brazil, among these disasters, floods, flash floods, and landslides account for the highest number of deaths, the latter being the most lethal. Bearing in mind the importance of monitoring areas susceptible to disasters, the REMADEN/REDEGEO project of the National Center for Monitoring and Natural Disaster Alerts (Cemaden) has promoted the installation of a network of soil moisture sensors in regions with a long history of landslides. This network was used in the present paper as a base to develop a system for moisture forecasting in those critical zones. The time series of rainfall and moisture were used in an inversion algorithm to obtain the geotechnical parameters of the soil. Then the geotechnical model was used in a forward calculation with the rainfall prediction to obtain the soil moisture forecast. The landslide events of March 2020 and May 2022 in Guarujá and Recife, respectively, were used as study cases for the developed system. The obtained results indicate that the proposed methodology has the potential to be used as an important tool in the decision-making process for issuing landslide alerts. • This paper presents a novel system aimed at predicting soil moisture conditions based on rainfall forecast data. [ABSTRACT FROM AUTHOR]

One of the challenges in the unification of the global vertical datum is to determine the vertical offset between the local vertical datum and the global vertical datum. Since 2015, the scientific community has been working on the unification of the global vertical datum, following the publication of the resolution for the definition and realization of an International Height Reference System. This paper aims to estimate the vertical offset in Brazil (Imbituba and Santana Data) by combining a regional gravity field model, using the Geodetic Boundary Value Problem approach applying the Remove-Compute-Restore procedure, and GNSS/leveling data. In the Imbituba vertical datum 1271 stations were used and 66 stations were connected to the Santana tide gauge. The results showed that the geopotential value of Imbituba was 62,636,849.87 ± 0.224 m2s-2, and the vertical offset concerning the reference surface (W 0) was 0.358 ± 0.023 m. In Santana, the geopotential value was 62,636,836.88 ± 4.108 m2s-2, and the vertical offset was 1.689 ± 0.420 m. The offset between Imbituba and Santana was computed once the physical connection between Brazil's two local vertical data is a challenge. The estimated value was 1.331 ± 0.421 m. This means the Santana vertical datum is 1.331 m higher than the Imbituba vertical datum. • Improving the Brazilian height system. • Using GNSS/leveling data to estimate the vertical offset in Brazil. • Connecting the Brazilian local vertical data to the International Height Reference Frame. [ABSTRACT FROM AUTHOR]

The Afonso Cláudio Intrusive Complex (ACIC) is a typical post-collisional intrusion from Araçuaí-West Congo orogen (AWCO). The ACIC intruded allanite-bearing orthogneisses from AWCO pre-collisional tectonic stage (Rio Doce arc related rocks) and paragneisses from Nova Venécia Complex and it is composed of two lowered off-centered monzogabbroic and monzodioritic cores surrounded by quartz monzonite high hills, showing intense magma mingling and mixing between these domains. Xenoliths attributed to the enclosing gneisses have been commonly found widespread in the quartz monzonitic rocks, while are occasional in the monzogabbroic and monzodioritic domain. This paper presents the first detailed investigation of the xenoliths hosted by an AWCO post-collisional intrusion, focusing on petrography, major and trace element geochemistry and U–Th–Pb monazite dating of the main xenolith types. For comparison, major and trace element data investigation of the ACIC enclosing rocks has also been conducted. The correlated xenoliths and ACIC enclosing rocks show partially similar geochemical features, however both show different REE and multi-element normalized patterns compared to the ACIC main rocks. These results suggest that correlated xenoliths and enclosing rocks are cogenetic, however both could not represent the main sources of magmas that generated the ACIC. Geochemical modeling of igneous processes of previous ACIC dataset considering the investigated xenoliths and enclosing rocks as the main assimilant material suggests that mixing was responsible for both ACIC main rocks similar geochemical patterns and linear trends in the bimodal diagrams. This modeling also indicates that the evolution of the ACIC main rocks was ruled by different processes. Fractional crystallization with minor influence of assimilation of enclosing rocks controlled the magmatic evolution of monzogabbro and monzodiorite related to an enriched mantle source, while coupled assimilation and fractional crystallization ruled the evolution of quartz monzonite possibly associated to lower crust magmas mainly contaminated by enclosing rocks. U–Th–Pb monazite dating of two xenoliths showed that these rocks preserved similar main ages related to different stages of ACIC and AWCO post-collisional evolution. Both xenoliths showed main older ages of 478 and 477 Ma which are related to ACIC intrusion during AWCO post-collisional stage, while younger ages of 431 and 427 Ma are probably related to the intrusion of syenogranite dykes that crosscut the ACIC, representing an extension of AWCO post-collisional magmatism or a later unrelated thermal event. Due to the similarities between the typical AWCO post-collisional intrusions, the insights brought about the evolution of ACIC magmas could be considered to the typical AWCO post-collisional mantle and crustal magmas. This first investigation of xenoliths hosted by an AWCO post-collisional intrusion has showed that these strange rock pieces could bring new and important insights about the AWCO evolution, which shows an amazing and long-lasting magmatism with common occurrence of poorly investigated xenoliths. • The ACIC is formed by the interaction between mantle and crustal contrasting magmas. • The contrasting magmas evolved ruled by different processes. • Assimilation of enclosing country rocks is an important process in ACIC evolution. • The xenoliths preserved two main ages related to ACIC and AWCO evolution. [ABSTRACT FROM AUTHOR]

This paper presents the geomorphological features of four areas of subtropical, southernmost Brazil displaying striking landforms developed upon Precambrian Camaquã Basin conglomerates in the southern Brazilian shield areas. The distinctive and unique features of the Serra do Segredo cuesta, the Rincão do Inferno canyon, the Casa de Pedra inselberg, and the Pedra da Cruz cap-shaped hills are important examples of such conglomerate geomorphology in South America and in Brazil, where few occurrences were available so far. They are the first documented conglomerate landforms in southernmost Brazil, widening the distribution of such terrains in South America and in the subtropical, southern hemisphere areas, considering recent global reviews. Besides the high scientific relevance for geomorphology as a whole, such features are important also for (1) evidencing the decisive role of lithology, structure, and water flows in the formation of such landforms; as well as (2) ecology and tourism, being distributed within and in the vicinity of the Caçapava UNESCO Global Geopark of southernmost Brazil. • Novel description of conglomerate geomorphology developed upon Ediacaran alluvial/fluvial deposits of the Camaquã Basin in subtropical, southernmost Brazil. • Different landforms developed according to bed tilting and arrangement, as well as to tectonic structures "pre-design". • Decisive role of lithology and water in shaping ranges and hills. • Contribution to a global distribution of conglomerate landforms, especially in humid, subtropical areas. • Geological heritage potential, features within and in the surroundings of the Caçapava UNESCO Global Geopark. [ABSTRACT FROM AUTHOR]

Reservoir characterization is extremely important for understanding and determining the behavior of hydrocarbon reservoirs. The geophysical well logging, widely applied in the oil industry, helps to obtain essential physical properties (acoustic, electrical, mechanical, radioactive and thermal) by deploying measurement devices in the drilled well. This project aims to carry out the geological characterization of hydrocarbon reservoirs in the Amazonas Basin through the analysis of well geophysical logs. Despite the oil-producing potential of the basin, there are few published papers that use geophysical well logging for reservoir characterization. For this study, composite log data publicly provided by ANP were used. Six exploratory wells drilled in AM-T-84 and AM-T-85 exploratory blocks in the Amazonas Basin were selected. By analyzing the geophysical logs of gamma ray, resistivity, density and neutron from these wells, it was possible to identify the hydrocarbon reservoir interval within the Monte Alegre formation and obtain estimates of thickness, shale volume and porosity. The identified reservoir is relatively thin, with an average thickness of 16 m. The obtained shale volume values were relatively high, due to the influence of shale layers present in the Monte Alegre formation. The effect of clay content affected the interpretation process of the well logs; however, it did not significantly impact the reservoir porosity estimation, which ranged between 10.4 and 23.4 %. • The analysis and interpretation of well logs can provide petrophysics properties of the petroleum reservoir. • The Amazonas Basin is one of the pioneering areas for hydrocarbon exploration in northern Brazil. • Despite the clay content present in the formation, relatively good porosity values were obtained for the reservoir. • The temperature values obtained range from 70 to 95 °C. They are contained in the oil generation range (65–165 °C). [ABSTRACT FROM AUTHOR]

Alkaline rocks of prevailing sodic composition form major ring complexes and stocks along a seismically active N–S structural lineament parallel to the Paraguay river course. All these occurrences are encompassed by the Alto Paraguay Province, their rocks corresponding to the oldest known alkaline magmatic activity in the Paraná Basin, with a Middle Triassic age of 241.5 ± 1.3 Ma. Intrusive rocks ranging from silica-undersaturated (nepheline and/or sodalite syenites) to silica-oversaturated (quartz syenites and alkali granites) and their fine-grained counterparts constitute the most abundant rock-types. Clinopyroxenes, associated amphiboles and varying amounts of biotite are the main mafic minerals present. Alkali feldspar (mainly mesoperthites and subordinate sanidine and anorthoclase) and feldspathoids (nepheline and/or sodalite) are widespread. A late-stage magmatic to metasomatic/deuteric mineral assemblage is mostly typical of miaskitic to agpaitic rocks of the Cerro Boggiani complex, whereas rare accessory silicate minerals are found in peralkaline syenites of the Cerro Siete Cabezas major intrusion. Positive Nb–Ta and Zr–Hf anomalies and negative Sr, P, and Ti spikes are common features to the whole province. REE behavior shows enrichment in LREE and strong LREE/HREE fractionation with various parallel subtrends. This paper addresses petrological aspects of the origin and evolution of these alkaline rocks. • The paper reviews knowledge about the Alto Paraguay Alkaline Province (border between Brazil and Paraguay). • The main rock types vary from undersaturated (nepheline and sodalite syenites) to silica-oversaturated (quartz syenites and alkali granites) and their fine-grained equivalents. • The intrusion of the alkaline bodies took place along an N–S-oriented structure that marks the boundary of the Pampia and Rio Apa cratonic blocks. • The rocks are dated from the Middle Triassic and constitute the oldest alkaline magmatic event on the edge of the Paraná Basin. [ABSTRACT FROM AUTHOR]

Magnetotelluric (MT) data from 49 broadband and 23 long period stations, covering periods between 10−3 and 104 s, were measured along a NNW-SSE profile of approximately 470 km, crossing the Parnaíba Basin, Borborema Province and São Francisco Craton in northeastern Brazil. The geotectonic scenario of the study region comprehends a complex structural framework formed during the Brasiliano orogenic collage. The MT data were processed to obtain the impedance tensor estimates for each MT site using a robust technique and then followed by a dimensional analysis via both the rotational invariants (WAL invariants) of the magnetotelluric tensor and the phase tensor. The two approaches indicated a three-dimensional nature of the region, allowing to proceed to 3D inversion, despite the data distribution along a profile. Several inversion trials of the full impedance tensor, tipper and tipper combined with impedance tensor resulted in a final 3D resistivity model, which suggests a division of the profile into three major zones. A sub horizontal resistive crustal block, interpreted as being part of the Parnaíba block, characterizes the western zone. A mosaic of resistive and conductive zones, which integrates the extended fold belt of the Borborema Province, composes the central zone. In the interface between the central and the eastern zones, there is a sub vertical conductive region limiting two resistive blocks, interpreted as a suture zone. This suture divides tectonic provinces and is supposed to be related with a Neoproterozoic collisional system. The 3D MT imaging recovered the structural framework under the Parnaiba Basin and marked the main lineaments. The paper suggests a distinct tectonic evolution for the complex assemblage of blocks in Northeast Brazil. • The 3D MT imaging allowed drawing a crustal model that recovers existing structures in great depth along the study region. • The 3D MT imaging recovered the structural framework under the Parnaiba Basin and marked the main lineaments. • The paper suggests a distinct tectonic evolution for the complex assemblage of blocks in Northeast Brazil. [ABSTRACT FROM AUTHOR]

Every year, Brazil grapples with the destructive impact of landslides, typically during the summer season. The National Centre for Monitoring and Alerts of Natural Disasters (Cemaden) places significant emphasis on studying these phenomena to understand their processes and causes more deeply. One key challenge faced in this endeavour is the procurement of geotechnical properties of the soil in high-risk areas, with soil moisture being a crucial factor. Collecting point samples for acquiring these geotechnical parameters is not only costly but also limited in providing a comprehensive two-dimensional or three-dimensional coverage. Therefore, the primary aim of the proposed project is to validate the method of acquiring soil moisture data through geophysical surveys in both 2D and 3D scenarios. Data was gathered from soil moisture stations within Cemaden's network and various collected samples to confirm the results. To generate more controlled yet realistic conditions, a sequence of field infiltration experiments was conducted. The findings, related to the ability of the geoelectric method to define soil moisture, derived from this project form an invaluable foundation for future investigations spearheaded by the Geodynamics Group and its collaborating institutions. • This paper presents a series of experiments to understand the method of acquiring soil moisture through the DC method. [ABSTRACT FROM AUTHOR]

This paper presents the first mapping of bedform morphological features on the Trindade Island shelf, with the goal of identifying and defining them. By using a side scan sonar, collecting seabed samples, and taking submarine photographs, five different morphological types were identified on this shelf: an erosive type: (i) characterized by the dispersion of rocks and rock blocks; and four depositional types: (ii) one formed by calcareous algal reefs, (iii) one composed by rhodoliths, (iv) one formed by medium sands with large symmetrical wave ripples, (v) and the last one formed by fine sands with asymmetrical wave ripples. The main result is a morphological map of the Trindade Island shelf, which shows the occurrence of these five seabed units. To further understand the sedimentological factors that affect the island shelf, we also examined the sediments that were collected for this study. Our results show that the amount of carbonate-formed grains on the collected sand sediments is higher than the amount of grains formed by the volcanoclastic ones, generated by the disaggregation of the main building on Trindade Island. The sediments formed by bioclastic grains are more frequently found in the coarser fractions than in the finer fractions when compared to lithic ones. • First seabed characterization on the Trindade Island shelf. • Boulders and rock outcrops occur at shallow depths, near the shoreline. • Rhodoliths and algal reefs are the main shelf seabed types. • Bioclasts are the main component that forms sandy deposits. [ABSTRACT FROM AUTHOR]

The paper focuses on the sedimentological, stratigraphic, and climatic implications of silicified fossil trunks found in the Missão Velha Formation (MVF) of the Araripe Basin in Northeastern Brazil. The rich fossiliferous plant assemblages in the MVF are primarily dominated by conifers, specifically a group known as Agathoxylon, and are associated with coarse sandstone and conglomerate fluvial beds. The MVF represents a late Jurassic-early Cretaceous formation deposited during the Early Rift phase of the basin. Silicified fossil trunks and woods from the MVF have been known since 1863, and previous studies have discussed their morphology, internal structure, and paleogeographic implications. Taphonomically, these macrofossils have been interpreted as hypautochthonous, meaning they originated from their growth sites. However, some authors have suggested an allochthonous origin for these fossils. Despite their significance, the sedimentological and stratigraphic characteristics of these fossil associations have received limited attention in previous research. We have collected the fosil trunks exclusively in the MVF, and they are restricted to the upper parts above an internal unconformity. Two main taphofacies were identified: T1 comprises coarse-to medium-sandstones, locally conglomeratic, with planar and trough cross-stratifications, with abundant fossil wood and trunks, and T2 defined as well-stratified pebbly conglomerates, with horizontal to cross bedding, with larger common fossil wood and trunks fragments. T1 taphofacies occur in most of the cross-stratified sandstones of the upper part of the MVF, T2 taphofacies (larger wood logs) are primarily concentrated in a coarse sandstone to conglomeratic bed strata at the top of the MVF. The preservation of the trunks is characterized by uncompressed fragments with poorly rounded edges. The cell walls are preserved by permineralization, with the spaces filled by silica, indicating short transport and rapid burial. The silicified fossil woods are found in foresets of planar and trough cross-stratifications, associated with coarse-grained to conglomeratic sandstones. These sandstones are highly abundant, sometimes forming anomalous concentrations, such as in the Grota Funda outcrop. The dimensions of the fossil trunks range from 5 cm up to 2 m in length, with some exceptionally large trunks measuring approximately 1.70 × 1.40 m. The investigated trunks exhibit various orientations, with some concordant and others dissenting from the surrounding strata. However, the majority of the fossil trunks do not show a preferential orientation. Orientation analysis of more than twenty logs suggests a predominant south paleocurrent direction trend, likely resulting from monsoon storms originating from a source area to the north. The assemblages were likely formed through putrefaction processes and late fragmentation, followed by size-selection through fluvial transport. The relatively short transport distance is indicated by the preserved edges, lack of preferential position, and the size of the trunks. Consequently, it is inferred that the trunks originated within the basin itself rather than being transported from the basement area, supporting their hypautochthonous character. The MVF and the associated plant remains bear resemblance to deposits of similar age in other Northeast Brazilian basins, such as the Recôncavo-Tucano-Jatobá, Sergipe-Alagoas, and Camamu-Almada basins, as well as the Gabon Basin in Western Africa. Evidence from the trunk taphofacies, stratigraphy and sedimentology of the MVF is consistent with a warm, seasonal, hot, and humid climate, indicative of a monsoon climate similar to other conifer forests in Gondwana during the Mesozoic era. • The rich fossiliferous plant assembly is dominated by conifers restricted to Agathoxylon and relates only to coarse sandstone and conglomerate beds deposits of the upper portion of the Missão Velha Formation. • The sandstone strata that hosts the fossil woods denotes subaqueous dune deposits. • High energy channels in shallow braided fluvial channels carried heavy logs. • Channels could be sudden causing great damage, carrying heavy logs in a short path. • Evidence from the fossil trunks and woods, stratigraphy and sedimentology of the Missão Velha Formation is consistent with a warm, seasonal, hot and humid climate, suggestive for monsoon climate [ABSTRACT FROM AUTHOR]

In this paper, we used seismic stratigraphy for the study of deposition and sea-level evolution on the São Sebastião Channel (SSC), southern Brazilian coast. About 60 km of high-resolution single-channel seismic lines were acquired to establish a 5th order seismic stratigraphy model for the area. After graphical processing for noise attenuation and enhancing of deep-reflections, we could interpret six seismic horizons and the acoustic basement which together defined six seismic units. Studying those units in a late Quaternary relative sea-level oscillations context, we propose a 4-phase deposition evolution model that took place since the Marine Isotopic Stage (MIS) 5e in the SSC area. The first phase comprises the deposition of seismic units U1 and U2 prior to MIS 4 with the deposition of one lowstand systems tract (LST) and one highstand systems tract (HST). Before the second phase, the sea-level dropped eroding the top layers of the previous units. During the second phase, after the Last Glacial Maximum (LGM), another LST (unit U3) was formed in one of the three stabilization periods of Upper Pleistocene/early Holocene sea-level rise on the Brazilian coast. Following an increase in sea-level rise velocity, we interpreted a transgressive system tract (unit U4) and another HST (unit U5) developed until the maximum sea-level of the Mid-Holocene, at 6 ky B.P during the third phase of our model. During the fourth phase, sea-level fall evolved to the present level, giving conditions to the deposition of the last HST (unit U6) interpreted in the region. • São Sebastião Channel recorded Pleistocene and Holocene sea-level oscillations. • Lowstand and highstand tracts can be interpreted with 5th order seismic stratigraphy. • Sea-level positions in Southern Brazil can be estimated through seismic stratigraphy. [ABSTRACT FROM AUTHOR]

This work presents a 1:10,000 geomorphological mapping of an area in southeastern Brazil, based on morphometric analysis of Digital Elevation Models (DEMs), while classical methods focus on photo interpretation. Data derived from the DEM include elevation, slope gradient, slope aspect, vertical and horizontal curvatures, amplitude, elongation and wavelength of landforms. These parameters were used along with slope shape and drainage patterns to classify the landforms according to the Land Systems method, in which portions of the landscape that presents similar terrains attributes are grouped from regional (low detail) to local (high detail) scales, respectively, Land Systems, Land Units and Land Elements. The São Paulo State geomorphological map at 1:1,000,000 scale is considered the best reference source, and was compared with the results obtained in this project. Two Land Systems, four Land Units and twelve Land Elements were identified in the study area. In this area, karst terrains are common and easily identified due their characteristics drainage patterns, amplitude and slope gradient. Karst terrain boundaries defined in this study do overlap with those defined in the state map, however the morphometric analysis allowed a better description of the terrain attributes used to define them. The terrain attributes derived automatically from the DEM enabled an accurate geomorphological classification of the study area. The methodology presented in this paper is considered effective for mapping landforms at a detailed scale and can be employed in regional scale mapping using coarser resolution DEMs. Image 1 • A geomorphological map was created based on DEM-extracted terrain attributes. • Attributes were grouped from low to high detail in Land Systems, Units and Elements. • The same Land Systems and Units of a map based on traditional methods were identified. • Land Elements were defined by attributes unavailable from aerial imagery. • Automatic identification of karst areas produced fair results to existing maps. [ABSTRACT FROM AUTHOR]

Analysis of ancient animal bone fractures can provide insights into ecological and behavioral aspects, as well as death processes and bone preservation modes. This paper describes and interprets the cause of a bone fracture observed in the fossil remains of a juvenile Myrmecophaga tridactyla (giant anteater) recovered from a limestone cave in Brazil. We identified an indirect bone trauma with a curved or spiral fracture line and a well-formed bone callus in the left ulna through a macroscopic and radiological examination. These features indicate that the giant anteater fell from a great height with an outstretched hand. • Presence of bone fracture in the ulna of a juvenile Myrmecophaga tridactyla caused by indirect bone trauma. • Presence of a well-formed bone callus, indicating that the animal survived the injury and underwent an advanced healing process. • The giant anteater likely fell from an elevated location and sought shelter in the cave after sustaining the injury. [ABSTRACT FROM AUTHOR]

The alkaline magmatism found in the Brazilian Equatorial Margin (BEM) in the Southwest Atlantic Ocean, such as that observed in Fernando de Noronha Archipelago, poses intriguing questions about its origin and its relationship to guyots and onshore magmatism of similar alkaline compositions in northeast Brazil. The Fernando de Noronha Archipelago (FNA) exhibits a broad spectrum of alkaline magmatism, ranging from foiditic to phonolitic/trachytic compositions. At the Enseada da Caieira , a group of intrusions reflects this wide variety from FNA. This paper presents a complete description of these intrusions based on petrography, lithogeochemistry, and mineral and isotopic chemistry, as well as thermobarometry and petrogenetic modeling. The new data are compared with data compiled from the FNA, BEM onshore and offshore magmatism, and the Vitória-Trindade Ridge (VTR). The intrusions are classified as trachyte, alkali-basalt/basanite, phonotephrite, and picrobasalt. The compositional diversity of dikes outcropping in a relatively small area suggests a complex petrogenetic evolution for the feeding system of the Fernando de Noronha Island. This is supported by the presence of porphyritic clinopyroxenes (for example) with compositional zoning, indicating multistage crystallization processes. Flow, resorption, and glomeroporphyritic textures are common. Skeletal crystals also occur as phenocrysts of olivine and clinopyroxene due to supercooling. Secondary minerals such as zeolites and carbonate commonly occur as fillers in amygdules. Values for Ɛ Nd range from +0.2 to +3.1. The Sr–Nd isotopic signatures suggest a mixture between an enriched component (EMII) and a depleted mantle component (DMM). A multi-approach thermobarometer using clinopyroxene, amphibole, and zircon mineral chemistry reveals different stages for crystallization, with pressure and temperature ranging from 320 to 1300 MPa and 750 to 1240 °C, respectively. The whole-rock lithogeochemistry modeling suggests a low degree of partial melting (around 2% or less) of an enriched source with variable proportions from spinel and garnet-lherzolite melting zones. • Petrography and mineralogy of alkali basalt, picrobasalts, basanite, trachyte and phonotephrites from Fernando de Noronha. • Geothermobarometry, textures and mineral chemistry is consistent with multi-stage crystallization processes. • Fernando de Noronha magmas were generated by low degree of partial melting from spinel and garnet-lherzolite mantle sources. • Sr–Nd isotopic signatures suggest a mixture between an enriched component (EMII) and a depleted mantle component (DMM). [ABSTRACT FROM AUTHOR]

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]

Banded Iron Formations (BIF) developed strongly during the Neoarchean – Paleoproterozoic Eras linked with global environmental processes such as the Great Oxidation Event (GOE) and changes in geodynamics, sea level, geobiology, hydrothermal systems, and sediment deposition conditions. BIF development and distribution worldwide are also related to supercontinent cycles, being a powerful tool to understand the evolution of plate tectonics. In this paper, we used field-based geological-structural data, petrography, X-ray diffraction, and lithogeochemical analyses to perform the first characterization of Banded Iron Formations at the Luis Alves Craton (LAC), Southern Brazil. The LAC BIF are classified as oxide and silicate facies, both with granoblastic texture. Oxide facies consists of quartz and magnetite. Besides these minerals, silicate facies contains olivine and ferrosilite, evidencing granulite metamorphism. Based on major elements oxide facies has a hydrothermal signature, with low content of Al 2 O 3 and TiO 2 , whereas silicate facies register a continental sediment contribution been more enriched in these elements, MgO, MnO, and CaO. Trace-elements also indicate the main source for both silicate and oxide facies, which is seawater with a major influence of low-T hydrothermal sources, besides continental sedimentation sources. The Ce/Ce × anomaly is true negative, representing oxidizing waters, which also may represent a shallow water column depth. The depositional environment is inferred as a shallow, restricted basin. Oxide facies represents sedimentation closer to hydrothermal vents and with weak influence from continental clastic sedimentation, while silicate facies represent sedimentation closer to an adjoining continental landmass. Oxide facies has more Algoma-like characteristics, such as higher Fe and Eu contents, Sm/Yb and Eu/Sm typical of higher hydrothermal fluid inputs, and low siliciclastic contribution. On the other hand, silicate facies resembles Superior-type BIF, with higher siliciclastic contribution, negative Ce/Ce × anomalies, and Eu/Eu* <1.8. In summary, we propose the LAC BIF is representative of a transitional environment from Algoma-to Superior-type. The first depositions of the LAC BIFs may have developed within an Algoma-like environment during the Neoarchean. The waning tectonic and volcanic activity during the Siderian shifted to a platformal environment, with shallower waters that may induce the deposition of carbonates typical of Superior-type deposits. The depositional basin may have been closed by the Rhyacian and those sediments were then pushed down to the lower crust and underwent granulite facies metamorphism. • Oxide and silicate facies BIFs were recognized in the Luis Alves Craton. • These BIFs register granulite metamorphism, having ferrosilite and olivine in their composition. • Through the geochemical data, the depositional paleoenvironment was recognized. • The sedimentary sources of BIFs are both hydrothermal and continental. • These BIFs have characteristics of both Algoma and Superior type deposits. [ABSTRACT FROM AUTHOR]

Karstic areas in Central Brazil show significant depositional and erosive facies placed within abandoned dry valley-systems and associated with fluviokarstic dynamics. These valleys have distinct depositional characteristics that offer sedimentary records of both past climatic events in the region and its current fluviokarstic system. The purpose of this paper is to point out and characterize such sedimentary packages, protected by dry valleys that were deposited up until the fluviokarstic transition, thus enabling the correlation of such sediments to past climatic events. The study is based on a combination of geomorphic and sedimentological analyses through the employment of multiple techniques, such as mineralogy, geochronology, stable isotopes, and granulometry, to the analysis of our case studies. These are the three dry valleys around the Ventura, Pedras and Extrema rivers, which in turn comprise the River Vermelho Basin, northeastern Goiás State. Our results suggest that the valleys contain fluvial deposits remnant from the transition of superficial fluvial flow to the underground karstic system. Records provide a general view of the depositional stages placed before and up until the period of fluvial capture in terms of their morphology, dynamics, and sediment architecture. OSL ages indicate that fluviokarstic processes had been in operation since 23 Ka, when the oldest river capture was found to have occurred. Depositions occurred in a reasonably continuous manner, mainly during the last 3.5 Ka, and concentrated around relatively dry and wet events, exhibiting typical depositional gaps in fluvial environments. Consequently, no relationship between the depositions and paleoclimatic events were observed for the analyzed fluviokarstic system. [ABSTRACT FROM AUTHOR]

This paper documents an investigation on the use of full waveform inversion to retrieve focal mechanisms of 11 micro-earthquakes (Mw 0.8 to 1.4). The events represent aftershocks of a 5.0 m b earthquake that occurred on October 8, 2010 close to the city of Mara Rosa in the state of Goiás, Brazil. The main contribution of the work lies in demonstrating the feasibility of waveform inversion of such weak events. The inversion was made possible thanks to recordings available at 8 temporary seismic stations in epicentral distances of less than 8 km, at which waveforms can be successfully modeled at relatively high frequencies (1.5–2.0 Hz). On average, the fault-plane solutions obtained are in agreement with a composite focal mechanism previously calculated from first-motion polarities. They also agree with the fault geometry inferred from precise relocation of the Mara Rosa aftershock sequence. The focal mechanisms provide an estimate of the local stress field. This paper serves as a pilot study for similar investigations in intraplate regions where the stress-field investigations are difficult due to rare earthquake occurrences, and where weak events must be studied with a detailed quality assessment. [ABSTRACT FROM AUTHOR]

Kimberlitic rocks are known in the São Francisco Craton, Brazil, since the 1980s when the De Beers started a prospective work in the Itapicuru River Greenstone Belt. However, 40 years later, the scientific knowledge about these occurrences is still very restricted. This paper presents new geological and petrographical data for the pipes of the "Brauna Kimberlitic Field". These rocks are exposed in a strongly eroded cratonic area of Northeastern São Francisco Craton and as expected, represent the deepest parts of these bodies, showing textural aspects and components typical of coherent volcanic rocks emplaced at deep crustal levels. The kimberlitic magmatic event resulted not only in the emplacement of macrocrystalline hypabyssal olivine archetypal kimberlites, here represented by the B3 (678–682 Ma) and B4 pipes (s.s. Former type 1 kimberlites), but also in hypabyssal macrocrystalline pyroxene-phlogopite- lamproite intrusions, as exposed in the B7 (641 Ma) pipe of the Brauna Field. Both magmas are rich in mantle-xenoliths and have potential for diamond ores. The observed features suggest the presence of multiple magmatic pulses – which acted as deep samplers, recorded in the diversity of xenoliths and xenocrysts – thus demonstrating the potential of these rocks for the comprehension of the first stages of evolution of the Early Earth as well as for understanding the formation of the metasomatized lithospheric mantle below the São Francisco Craton. The new data for these hypabyssal facies, macrocrystic pulse of kimberlitic rocks in the Brauna Field, São Francisco Craton, Brazil, can be used to characterize the petrographic and mineralogical heterogeneities of a Neoproterozoic alkaline-ultrapotassic magmatic event that shows a kimberlite-lamproite transitional nature. The petrogenetic knowledge presented for the São Francisco Craton kimberlites and lamproites – accordingly to the most recent classifications for these rocks – include textural-genetic data, geotectonic environment, and intrusive-spatial context, setting these rocks at the stage 5 of present-day kimberlite classification scheme. Moreover, the integration of such data and the close spatial associations of kimberlites, lamproites, lamprophyres, syenites and shoshonites allowed to create a solid interpretation of the rock formation processes that correlates these Neoproterozoic alkaline ultrapotassic magmas to the reactivation of ancient mantle conduits in a thick lithosphere that overlies a previously metasomatized mantle and intrude a metal-rich craton environment. • Current models and nomenclature of kimberlite-lamproite rocks highlight the importance of detailed petrogenetic studies. • Detailed petrographic studies points to the usefulness of deepening the discussion on kimberlite rocks nomenclature. • The pipes of the BKF present textural characteristics and components typical of massive coherent rocks emplaced at deep crustal levels. • B3/B4 are classified as coherent coarse-grained, macrocrysts-rich, hypabyssal-facies, mega-graded, diamondiferous-olivine-kimberlite. • Otherwise, B7 is interpreted as an intrusive plug of a massive coherent coarse-grained, hypabyssal, diamondiferous-phlogopite-lamproite. • The petrogenetic and textural classification of BKF, presented in this paper, contribute to understanding of kimberlite and lamproite magmas. • BKN petrogenesis contribute to understand the metasomatized mantle and ore deposits of the Sao Francisco Craton. [ABSTRACT FROM AUTHOR]

Catfish fossils are mainly represented by disarticulated material, most of which is dorsal and pectoral spines. Morphological data on dorsal and fin spines are described. These materials, collected from two sites of the Adamantina and Marilia formations, Late Cretaceous, of the Bauru Group, reveal the morphologic diversity of the freshwater siluriform taxa. This fauna represents one of the oldest samples of catfish diversity in South America, shortly posterior to its separation from Africa during the Cretaceous. A comparative analysis of these materials with the pectoral and dorsal spines of fossil and extant taxa demonstrated a mosaic of similarities shared with several catfishes, such as the families Bagridae - dorsal spine of morphotype one, Pimelodidae, Ictaluridae and †Bachmannidae - dorsal spine of morphotypes two and three, and Ictaluridae and †Hypsidoridae - pectoral spines of morphotypes one and two. • This paper offers a detailed description of dorsal and pectoral spines of Siluriformes from the Bauru Group. • The Siluriformes specimens present a morphologic diversity which comprises three morphotypes of dorsal spines and two morphotypes of pectoral spines. • The dorsal spine of morphotype one shares features with some Bagridae. • The pectoral spines of morphotypes one and two are most similar to two North American families, †Hypsidoridae and Ictaluridae. • The dorsal spine of morphotypes one and two are like Pimelodidae, Ictaluridae and †Bachmannidae. [ABSTRACT FROM AUTHOR]

The transgressive-regressive events due to changes in the eustatic sea level represent the occurrence of an epeiric sea in Western Gondwana. This event is recorded in the carbonate-siliciclastic succession exposed in the central portion of the Parnaiba Basin, Northern Brazil, mainly represented by densely fossiliferous deposits, with mollusks, brachiopods, corals and microfossils, related to the upper member of the Piauí Formation. Outcrop-based facies/microfacies and stratigraphic analysis of this succession allowed the individualization of two facies associations (FA), representative of a shallow carbonate platform system adjacent to a coastal dune field. The FA1– dune field/interdune, comprises well sorted, intensely biortubated, fine to medium-grained sandstone with even parallel and tabular cross stratification, as well as translatent climbing ripple cross-lamination. FA2-shallow sea deposits consist of fossiliferous pelletal carbonate and microspar carbonate layers, laterally continuous for hundreds of meters, interbedded with centimetric beds and lenses of organic shale with small pyrite crystals. Covariant values of positive δ18O carb and negative δ13C carb for the carbonate profiles, together with intense substitution of primary constituents by dolomite and an abundance of associated organic matter contributed towards determining an organogenic dolomitization model. Although the Pennsylvanian records a long icehouse event, glacioeustatic fluctuations were common during the Moscovian and Kasimovian. The icehouse periods contributed to the semi-arid to desert conditions that shaped the aeolic environments of the Piauí Formation. Later greenhouse events favored a rise in the sea level and development of an extensive epicontinental Pennsylvanian sea that extended throughout Western Gondwana called the Itaituba-Piauí sea in this paper, which connected the Andean, Solimões, Amazonas and Parnaíba basins. • Carbonate-clastic sedimentation in the Penssylvanian of Parnaíba Basin. • Coastal wind dunes from the top of the Piauí Formation. • Piauí Formation evidences the epicontinental sea in West Gondwana. • Dolomitization and δ13C carb and δ18O carb of shallow sea carbonates in the Piauí Formation. • The carbonate factory on the great lakes/sea were ceased. [ABSTRACT FROM AUTHOR]

Focal-mechanism determination of weak events recorded in sparse networks is challenging. First-motion polarities are often available at relatively distant stations, and waveforms only at a few near stations can be modeled. A two-step approach of how to combine such data has been suggested recently (Cyclic Scanning of the Polarity Solutions, or CSPS method; Fojtíková and Zahradník, 2014). It starts with creating a suite of first-motion polarity solutions, which is often highly non-unique. The next step consists of repeating full waveform inversion for all polarity solutions. Even few stations may efficiently reduce the non-uniqueness of the polarity solutions. Centroid depth, time, scalar moment and uncertainty estimate of the well-fitting double-couple solutions are obtained. The CSPS method has been extended in this paper by adding a new feature, i.e. repeated inversions using multiple first-motion polarity sets. The polarity sets are created by projecting the stations on focal sphere in several available velocity models, thus accounting for the takeoff angle uncertainty. The multiple polarity sets provide assessment of the CSPS solution stability. These ideas are demonstrated on a comprehensive analysis of a rare event in central Brazil. It is the Mw ∼4 mainshock of the Mara Rosa 2010 earthquake sequence (Barros et al., 2015, Carvalho et al., 2015). We employ polarities at 11 stations (distances < 730 km) and invert full waveforms at two stations (CAN3 and BDFB at distances ∼120 and 240 km), for 0.1–0.2 and 0.05–0.125 Hz, respectively. Six polarity sets reflect the takeoff angle uncertainty. The obtained CSPS results are very stable across all the polarity sets (in terms of depth, Mw, and strike/dip/rake angles). It is found that the Mara Rosa mainshock mechanism deviated from the composite solution of the whole sequence by 38°. The paper also includes a test simulating situations at which just a single waveform is used, and how it negatively affects the solution stability. [ABSTRACT FROM AUTHOR]

The Paraná Magmatic Province (PMP), one of the largest magmatic provinces on Earth, is composed of lava flows, dike swarms and sills that occupy thousands of kilometers across central-eastern South America. The Campinas-Jaguariúna Sill (CJS) is a large (>50 m thick and ±150 km2) diabase intrusion showing frequent medium- to coarse-grained gabbroic segregations and was emplaced at the interface between the Precambrian basement and sedimentary rocks in the northeastern Paraná Basin. This paper applies airborne magnetic and geochemical modeling to help understand the emplacement mechanisms and petrological evolution of the CJS. Magnetic field filtering techniques demonstrate that the CJS continues for tens of kilometers in the subsurface; analogous features are shown to be associated with other neighbor diabase occurrences, creating lobe-shaped structures that seem to freeze their original geometry and are not fully exposed by the current erosion levels. Petrological modeling indicates that the parental magma of the CJS was emplaced at ∼1 kbar, 1000 ppm H 2 O, and oxygen fugacity near FMQ-1. The gabbroic segregations, exposed as cm- to dm-sized sheets and eye-shaped lenses, are more evolved than the host diabase and can be shown by geochemical modeling to correspond to residual melts formed by crystal fractionation in a closed system. The parent magma of the CJS is akin to the more primitive Paranapanema magma type of the PMP, and we tested the possibility that sills intruding upper sedimentary layers may be part of a single episode of intrusions. For this purpose, we used geochemical data from the well-studied Limeira Sill, which is akin to the more evolved Pitanga magma type. Our modeling shows that, under crystal fractionation in the representative system condition, the CJS starting compositions cannot generate the Limeira rocks. • Coarse-grained segregation veins concentrated at the top of the sill correspond to residual melt after 25–65% crystallization. • Magnetic data highlights dimensions much more expressive than previously mapped, fitting these occurrences as a sill complex. • The CJS and the Limeira Sill are not cogenetic, at least three pulses of magma intrusion affected this region. [ABSTRACT FROM AUTHOR]

Martin Vaz Archipelago is a group of four islands formed by a succession of melanephelinite-phonolite rocks with Plio-Pleistocene ages, representing one of the latest volcanic manifestations of the Vitória-Trindade Ridge, in the South Atlantic Ocean, Brazil. This paper presents for the first-time fluid and mineral inclusions data, based on petrography and Raman spectroscopy. Olivine phenocrysts and macro phenocrysts from Atobá Formation melanephelinite host several amounts of CO 2 -rich fluid inclusions, although the post-entrapment process such as brittle failure, and reactions between fluids and the host mineral played a major role in these fluid inclusions evolution. Mg-rich carbonates (e.g., magnesite and dolomite) were identified as secondary minerals in the fluid inclusions walls, probably derived from these reactions. Dolomite secondary minerals formation could be related to carbonatitic fluids or carbonate-rich fluids that can be generated by a deep carbon mantle outgassing. Serpentine (antigorite) and Ca–Ti-perovskites were also found as mineral inclusions in olivine phenocrysts. Serpentine is evidence of great water activity suggesting that fluids involved in Martin Vaz genesis could have had at least during one stage of its evolution an aqueous or even an aqueous-carbonic composition. Ca–Ti-perovskite inclusions in mantle minerals have been related to eclogite-derived carbonatite metasomatic melts or to the serpentinization process in mantellic rocks, ruled by water remobilization of CaO and TiO 2. In the phonolite rocks from Atobá Formation (João da Nova Member), hydroxyfluorapatite was recognized as hosting carbonate-rich melt inclusions. These apatites with incorporated volatile phases (e.g., fluorine and OH groups), and carbonate-rich melt inclusions, together with the presence of SO 3 -rich nosean phenocrysts are evidence of a carbonate-fluorine-sulfate brine that could be formed in the latest stages of magmatic differentiation of Martin Vaz rocks. [Display omitted] • CO2-rich fluid inclusions in Martin Vaz Archipelago. • Mg-rich carbonates (e.g. , magnesite and dolomite) as secondary minerals in fluid inclusions. • Serpentine (antigorite) and Ca-Ti-perovskites were also found as mineral inclusions in olivine phenocrysts. • Raman spectroscopy [ABSTRACT FROM AUTHOR]

The Morro do Engenho lateritic nickel deposit results from the action of weathering processes on the alkaline mafic-ultramafic rocks that make up the Cretaceous zoned intrusive body belonging to the Goiás Alkaline Province. Historically, the deposit is classified as a silicate one, and mineralization is present especially in phyllosilicates such as serpentine and chlorite. By identifying Ni-bearing phases and providing the lithogeochemical characterization of weathering profiles, this study aims to provide further insights into the metallogenetic processes and controls acting on the mineralization of the Morro do Engenho lateritic Ni deposit. The following methods were used: petrographic studies, SEM-EDS, XRD and lithogeochemical characterization of the weathering profiles developed on each of the parent rocks that make up the body. The Morro do Engenho intrusive massif is formed by a dunite core, surrounded by a peridotite/pyroxenite zone, an alkaline gabbro zone and more externally by a syenite-nepheline zone. The lateritic profile constitutes eight weathering horizons, stacked one upon another from the bedrock namely: (i) saprock, (ii) lower saprolite, (iii) ferruginous saprolite, (iv) ocher saprolite, (v) plasma zone, (vi) lateritic duriccrust, (vii) silcrete and (viii) topsoil. Most Ni mineralization occurs in the lower saprolite, ferruginous saprolite and ocher saprolite zones. The findings pointed to the presence of Ni in silicate mineral phases, represented by serpentine, chlorite, smectite, as well as in Fe and Mn oxyhydroxides. The depressed area, located between the two major topographic elevations, has the highest Ni enrichments, which according to mass balance calculations can account for up to 40%. Hydrodynamic factors, by dissolution/precipitation of silicates in saprolite horizons of dunite core, are suggested as possible agents in the remobilization of Ni, among other mobile elements, to topographically flat zones. The geometry of the Morro do Engenho deposit show that lateral redistribution by hydrodynamic factors could also account for the mineralization of areas peripheral to the dunite core, composed of pyroxenite and gabbro-derived lateritic profiles. The direction of regional groundwater flow, strongly influenced by topography, would also be an important factor in the remobilization of Ni, as well as the mechanical transport of lateritic materials. Silicate mineralization predominates in the Morro do Engenho deposit, concentrated in Mg hydrosilicates and clay minerals; oxide mineralization also occurs, mostly in Fe and Mn oxyhydroxides. The findings discussed in this paper can broaden the understanding of metallogenetic processes involved in the genesis of lateritic nickel deposits.. • Lateritic profiles derived from serpentinized dunite, pyroxenite and gabbro containing Ni mineralization. • Presence of oxide–silicate mineralization of Ni. • Ni concentrations affected by hydrodynamics and mechanical transport of lateritic materials. [ABSTRACT FROM AUTHOR]

This work presents a few comments on the paper "Relative sea-level curve during the Holocene in Rio de Janeiro, Southeastern Brazil: A review of the indicators - RSL, altimetric and geochronological data". Surprisingly the authors omitted in this review a former discussion on the interpretation of paleo-sea level indicator and paleo-sea level reconstructions on the Rio de Janeiro coast that questions their results. Therefore, at this present work we resume the previous discussion. We conclude that although at the commented paper the altitudes of the paleo-sea level indicators were determined precisely, they did not consider the vertical distance between a given a paleo-sea level indicator and its current homologous one, and thus do not indicate paleo-sea levels. [ABSTRACT FROM AUTHOR]

The aim of this paper is to reconstruct an 11,000-year history of depositional environmental change in southeastern Brazil, based upon the integration of particulate organic matter and stable isotope (C and N) data from a 136-cm sediment core from Lake Canto Grande. These proxies are used to explore the evolution of terrestrial and marine influence on the lake. Isotopic (δ 13 C: −27.87‰ to −31.9‰; δ 15 N: −0.07‰–4.9‰) and elemental (total organic carbon - TOC: 0.58%–37.19%; total nitrogen - TN: 0.08%–1.73%; C/N: 0.3 to 54.7) values recorded in Lake Canto Grande suggest that the sedimentary organic matter was derived from mostly C 3 land plants and freshwater phytoplankton. Particulate organic matter and cluster analyses distinguished four associations characterized by the predominance of amorphous organic matter, followed by phytoclasts and palynomorphs. These results indicate two different phases of lake evolution. The first phase (136 - 65 cm; ∼10,943 cal yr. B.P. to ∼8529 cal yr. B.P.) is recorded by sand layers interbedded with mud, which contain amorphous organic matter (AOM, 45–59%) and phytoclasts (opaques - OP: 6–18%; non-opaques – NOP: 17–23%) which indicate a floodplain area. The second phase (65–0 cm; ∼8529 cal yr. B.P. to ∼662 cal yr. B.P.) comprises mud, AOM (68–86%) and palynomorphs (PAL, 8–16%) related to lake establishment comparable to modern conditions. Thus, characterizing particulate organic matter, in combination with stable isotopes, proved to be invaluable proxies for lacustrine paleoenvironmental change through the Holocene. [ABSTRACT FROM AUTHOR]

This paper describes the carbonate–siliciclastic system of the equatorial continental shelf of NE Brazil (East Ceará) based on X-ray fluorescence (XRF), grain size, CaCO 3 , shallow seismic and remotely operated vehicle (ROV) analyses. Data were obtained for two sectors: 1) Halimeda Bank (HB), inner shelf (−12 m), and 2) transverse profile (TP), inner to outer shelf-upper slope (−5 to −100 m). In total, 72 samples were collected, and 29 km of seismic lines (HB) and ROV profiles (HB and TP) were surveyed. The main chemical elements were Ca and Si (93%). These elements occur in two types of shallow marine sediments: carbonate (mainly autochthonous) and siliciclastics (terrigenous/allochthonous/relict). With respect to the chemical elements, a strong negative correlation was observed between calcareous (Ca and Sr) and siliciclastic (Si, Al, and K) components. Strontium does not always show a strong positive correlation with Ca. The average CaCO 3 contents of 81% and 91% were determined for the HB and TP, respectively. The profiles show a predominance of carbonate sediments; however, the HB demonstrates a greater continental influence (inner shelf). The grain size presents a prevalence of sand (82%) in relation to gravel (18%). This particle size variation is mainly due to the breakdown of Halimeda nodules, siliciclastic sediments in the finer fraction (>2.5Φ), and the presence of gravel with iron coating (relict). Two types of echo-characters have been identified. Both are associated with the large presence of carbonate sediments. Echo I shows the bottom surface with continuity in the sub-bottom without a subsurface reflector. Echo II presents a discontinuous subsurface reflector. The ROV allowed the observation of algae patches in higher floors and gravelly and sandy bioclastics in the lowest sectors. Large patches of calcareous green algae, Halimeda , occur in the inner shelf below the 15 m isobath, mainly due to the semi-arid climate (weak sediment supply from the mainland), geographical position (equatorial) and oceanographic conditions (hydrodynamic and biogeochemistry). It has been concluded that the seafloor of the semi-arid continental shelf of East Ceará (NE Brazil) shows modern predominance of carbonate deposition based on the lack of contaminants, geochemical purity of carbonate sediments, and high percentage of CaCO 3. The conditions for exploitation in the intermediate sector are provided. However, it would be ideal to perform punctual extraction and analyze the resilience and regeneration of Halimeda incrassata and the consequences for fisheries (important economic resource of the region). [ABSTRACT FROM AUTHOR]

The Late Neoproterozoic to Early Paleozoic Jaibaras Basin is located between the southeastern margin of the Médio Coreaú Domain (MCD) and northwestern edge of the Ceará Central Domain (CCD) of the Borborema Province, Northeastern Brazil, which is also the location of the main axis of the Transbrasiliano Lineament. The lower volcano-sedimentary rocks in the Jaibaras Basin are composed of two lower Vendian-Cambrian sedimentary units, Massapê paraconglomerates and Pacujá reddish sandstones, and one volcanic unit, the Parapuí Formation. The whole set is partially crosscut by two post-tectonic granite suites, the Mucambo and Meruoca plutonic bodies. The upper Cambrian-Ordovician sequence in the basin is represented by the polymitic conglomerates of the Aprazível Formation. In order to gain information on the relationship between magmatic and sedimentary events, in this paper we present new U-Pb zircon and K-Ar geochronological analyses that have been carried out on both volcanic and plutonic magmatic lithotypes. According to our data, emplacement of the Meruoca Pluton took place over a large time interval (539 Ma to 523 Ma), and was synchronous with the emplacement of the Mucambo Pluton (532 Ma) and at lower part of the Parapuí Suite (535 Ma). The last ductile event related to the movement of the Sobral-Pedro II Shear Zone is dated at 530 Ma, and the subsequent emplacement of the Aroeira Suíte dikes occurred between 524 and 500 Ma (Middle Cambrian). Finally, at 492-484 Ma is the age of cooling of the magmatic system related to the Aroeiras Suite. [ABSTRACT FROM AUTHOR]

This work presents a detailed taxonomic study on the marine ostracods from the Paraíba Basin, northeastern Brazil, in wells from the wells Itamaracá-1IT-03-PE and Poty-1PO-01-PE, which record the Maastrichtian–Danian boundary. Besides the taxonomic data, this paper contributes to the paleoenvironmental knowledge of Cretaceous–Paleogene ostracods from the Paraíba Basin. The analysis of 98 samples of the well Itamaracá-1IT-03-PE and 59 samples of the Poty-1PO-01-PE resulted in the record of 34 ostracode species, all representative of a marine environment with normal salinity. Seven new species are proposed: Cytherella centrocompressa sp. nov.; Cytherella paraibensis sp. nov.; Neonesidea potyensis sp. nov.; Bythoceratina spinosa sp. nov.; Eucytherura ventrotuberculata sp. nov.; Langiella fauthi sp. nov. and Protobuntonia punctatum sp. nov. [ABSTRACT FROM AUTHOR]

This paper presents Nd–Hf isotopic data for granitic rocks of both the Matupá (∼1859–1881 Ma) and Teles Pires (∼1790–1793 Ma) intrusive suites located in the south-central region of the Amazonian Craton, central Brazil. The Matupá Intrusive Suite consists of two facies of I-type granites with calc-alkaline affinity emplaced in volcanic arc settings. Facies 1 is composed of syenogranite and monzogranite, and facies 2 is composed of granodiorite. The Teles Pires Intrusive Suite varies from syenogranite to monzogranite with calc-alkaline signature that is consistent with mature magmatic arc settings. The Matupá Intrusive Suite derives from a source with Hf model ages ranging between 2.4–1.91 Ga and εHf (t) between +5.71 and −5.50. Zircon grains in the Matupá Intrusive Suite that are correlatable with the Creporizão Intrusive Suite show Hf model ages of between 2.0 to 2.4, and εHf (t) of −3.76 to + 4.10, while the zircon grains correlatable with the Tropas Intrusive Suite show Hf model ages of 2.1 to 2.4 Ga and εHf(t) of −3.93 to + 2.50. Both facies of the Matupá Intrusive Suite provide εNd (t) values varying from −0.61 to −1.66. The wide range of εHf (t) values (from −5.50 to +5.71) in contrast to the uniformly negative εNd (t) values (from −1.66 to −0.61) of the Matupá Intrusive Suite suggest that Nd–Hf decoupling took place in the magma source during to magma mixing processes. Nd–Hf isotope analyses of the Teles Pires Intrusive Suite reveal a source with Hf model age of between 2.3 and 1.9 Ga. This is indicative of mantle contribution and crustal reworking with values of εHf (t) ranging from +7.17 to −3.3, while other values suggest a more crustal contribution with εNd (t) from −0.07 to −0.71. Crustal contribution in the genesis and magmatic evolution of the Teles Pires Intrusive Suite is also evidenced due to the presence zircon grains inherited from Matupá Intrusive Suite. Zircon inheritance record a distant parental source coeval with the Matupá Intrusive Suite. This paper proposes that the origin and evolution of the Matupá Intrusive Suite is linked to the Cuiú-Cuiú Magmatic Arc while the origin and evolution of the Teles Pires Intrusive Suite is linked to the Juruena Magmatic Arc. Another hypothesis is that both suites were generated and evolved from a single magmatic arc. The Juruena Magmatic Arc is divided into two geographic segments. An eastern segment with a magmatic evolution marked by the interaction of crustal components during the orogenic phase of the Cuiú-Cuiú Magmatic Arc (Tapajós Domain of the Tapajós-Parimá Tectonic Province), and a western segment whose magmatic evolution is marked by rebound of the Juruena Magmatic Arc. • Amazonian Craton. • Teles Pires and Matupá intrusive suites. • Paleoproterozoic granites. • Nd–Hf isotope. • Magmatic arc. [ABSTRACT FROM AUTHOR]

The Southern Brasília Orogen is the result of Ediacaran continental collision between the active margin of the Paranapanema paleocontinent and the passive margin of the São Francisco paleocontinent. The active margin was deformed into the Socorro-Guaxupé Nappe and the associated Embu Domain. This paper presents new U–Pb zircon data and geothermobarometric estimates that allow to reconstruct the metamorphic evolution in these upper plate units. A pre-collisional metamorphism M1 with an age peak in metamorphic rims of zircon grains in the range 680–630 Ma is related to the development of the Socorro-Guaxupé magmatic arc with batholiths dated in a similar time span, 690 - 630 Ma. This metamorphism reached medium pressure granulite facies, now exposed by the tilted uplift and erosion due to the collision. Another peak is detected in metamorphic rims of zircon grains, in the range 630–590 Ma, labeled M2, related to the collision and corresponds to the main metamorphism in the lower plate and accretionary wedge-like nappe stack, underlying the Socorro-Guaxupé Nappe. This nappe stack was affected by greenschist facies metamorphism in the autochthonous underlying craton, grading to high pressure granulite facies in the upper nappe, with local occurrences of retroeclogite lenses. In the Socorro-Guaxupé Nappe and Embu Domain this main metamorphism (M2) is characterized by three metamorphic zones decreasing in grade with distance from the suture: a granulite facies orthopyroxene bearing zone; a high temperature amphibolite facies zone and a lower amphibolite facies zone. Geothermobarometric results in mineral associations related to M2 show temperatures decreasing from about 770 °C to ∼620 °C and pressures decreasing from about 9 kbar close to the suture to about 5 kbar in the southern and western parts of the studied region. On the upper Paranapanema plate, relative to the Socorro-Guaxupé Nappe and Embu Domain units, at the base of the plate, an older metamorphism (M1) is verified with temperatures between 960 and 890 °C and pressures between 11 and 9 kbar, reequilibrated at approximately 700 °C with a pressure of about 9 kbar (M2, continental collision). For this reason, it can be assumed that the rim of the Paranapanema plate was exhumed during the continental collision, since the temperature and pressure of the metamorphic peak determined during the continental collision are lower than those determined for the pre-collisional magmatic arc metamorphism. • Active margin in the Paranapanema Paleocontinent. • Metamorphism related to magmatic arc stage. • Exhumation of the upper plate during the Brasilia Meridional continental collision. • Arc metamorphism superimposed by collisional metamorphism of lesser degree. [ABSTRACT FROM AUTHOR]

The Dom Feliciano Belt, southernmost Brazil and Uruguay, is a Neoproterozoic to Cambrian mobile belt that resulted from the convergence of the Kalahari, Congo, and Río de la Plata cratons. The present paper focuses on post-collisional granites located in the eastern sector of this belt, in the Porto Alegre region, RS, Brazil. The studied rocks yield crystallization ages of ca. 600 Ma and intrude subduction-related, calc-alkaline gneisses from the host basement. This work presents novel isotopic data (Sr-Nd-Pb) for representative samples of the Viamão, Porto Alegre, and Itapuã intrusive suites. For the Viamão Intrusive Suite, the results (87Sr/86Sr t = 0.7089–0.7168; εNdt=−6.0 to −6.7; T DM = 1.4–1.5 Ga; 206Pb/204Pb = 18.20–19.71) suggest mixing of mantle (DM) and Paleoproterozoic crust-derived sources (Arroio dos Ratos Complex, a remnant of the basement). For the Porto Alegre Intrusive Suite, the results (87Sr/86Sr t = 0.7090–0.7437; εNdt=−4.2 to −8.3; T DM = 1.3–1.8 Ga; 206Pb/204Pb = 18.89–22.19) suggest mixing of mantle (HIMU) and Tonian-Cryogenian crust-derived components (Chácara das Pedras Gneiss, a remnant of the basement). In turn, the results for the Itapuã Intrusive Suite (87Sr/86Sr t = 0.7116–0.8733; εNdt=−1.6 to −6.0; T DM = 1.2–1.6 Ga; 206Pb/204Pb = 18.44–22.20) suggest mixing of the mantle (possibly HIMU) and a Nd-depleted, crust-derived component (in comparison to the source of the Porto Alegre Intrusive Suite). All the studied suites are interpreted as being formed in a Neoproterozoic post-collisional setting. The mantle-derived signatures (DM and HIMU) are interpreted as the result of the partial melting of remnants of former oceanic slabs related to previous subduction events. In turn, the crust-derived signatures are interpreted as the result of assimilation of basement rocks. We suggest that the post-collisional magmatism of this sector of the Dom Feliciano Belt is associated with a deep hot zone. • New isotope data (Sr-Nd-Pb) for Porto Alegre granites. • Magmatism associated with a deep hot zone. • Post-collisional crust-forming stage of the Brasiliano/Pan-African orogenic cycle. [ABSTRACT FROM AUTHOR]

This paper describes the performance of addition rates of basaltic breccia and agricultural gypsum on clay stabilization and nutrients release of a solodic Planosol from a degraded borrow area located in Southern Brazil. A leaching experiment was carried out in PVC cylinders filled with 1.5 kg of soil (C horizon), in which two chemical amendments were added in three different proportions: a) basaltic breccia in 7, 14 and 21 Mg ha−1 doses; b) agricultural gypsum in 7, 14 and 21 Mg ha−1 doses; and c) a standard soil, without chemical correction. Distilled water (300 mL) were added every 7 days for 20 weeks and the pH, electrical conductivity, calcium, magnesium, sodium and potassium contents and the water-dispersible clay were analyzed in the collected leachates. Gypsum was more efficient than basaltic breccia to promote clay flocculation, even at the lower rate (7 Mg ha−1). The application of basaltic breccia up to 21 Mg ha−1 reduced the amount of nutrients released directly to the soil solution, reducing soil leaching. The application of basaltic breccia at the dosage of 7 Mg ha−1 was able to reduce more than 65% of the water-dispersive clay from the degraded solodic Planosol. • Basaltic breccia reduce soil leaching. • Basaltic breccia reduce water-dispersive clay. • Basaltic breccia restore main ecological functions of a degraded land. [ABSTRACT FROM AUTHOR]

This paper focuses in the description, radiocarbon dating and isotopic analyses (δ 13C, δ 18O) of new fossils of Panthera onca from the late Pleistocene of the Brazilian Intertropical Region. This paper focuses on the paleoecology of this large cat and is of major importance to understand ecological niches in evolutionary time. Radiocarbon datings and stable isotope compositions (carbon and oxygen) were determined from the structural carbonate of enamel for two fossils of Panthera onca found in two caves in Bahia, Brazil. Isotopic data available of large faunivores and other extinct and extant herbivorous taxa from the late Pleistocene of the Brazilian Intertropical Region were used for paleoecological interpretations. Carbon and oxygen isotopic values from P. onca allow us to suggest that these individuals lived in arboreal savanna habitat between 26 and 33 kyr BP, could reach 209 kg and feed mainly on Nothrotherium maquinense , Tapirus terrestris and Alouatta sp., being a specialist. The isotopic niche overlap with Smilodon populator and Arctotherium wingei was high, while with Protocyon troglodytes was low. In the late Pleistocene P. onca probably suffer high ecological pressure by S. populator , while with A. wingei this could not occur, as this species could be mainly herbivorous. • Two new records of Panthera onca fossils in caves of Bahia, Brazil. • Both remains are from the late Pleistocene (29 ka and 36 ka). • Body mass estimation varied between 89 kg and 209 kg. • The isotopic diet of P. onca was based mainly in ground sloths, tapirs and monkeys. • onca probably suffer high ecological pressure by S. populator. [ABSTRACT FROM AUTHOR]

Ostracods are microcrustaceans that inhabit different aquatic environments and are frequently used in paleoecological interpretations and biostratigraphic studies. The Barreirinhas Basin, Northern of Brazil, contains a well-preserved ostracod assemblage in its sedimentary rocks of early and late Cretaceous age, which have been so far poorly studied. This paper contains the first taxonomic identification of the ostracod assemblages, as well as the elaboration of paleoenvironmental and biostratigraphic inferences, for the Cretaceous of the Barreirinhas Basin. The studied material consists of 147 samples from the wells 1-MAS-1A, 1-MAS-3A, 1-MAS-4A and 1-MAS-14A. 495 specimens were recovered, distributed between 40 species, 16 genera and 9 families, including three new species. Based on previously established biozones for the Sergipe basin, two biozones were identified: the Nigeroloxoconcha aff. Nigeroloxoconcha sp. GA A 22 Range Zone, of lower Cenomanian age; and the Brachycythere sapucariensis Interval Zone, of Turonian to middle Coniacian age. Finally, three distinct ostracod assemblages were defined: Assemblage 1, dominated by Conchoecia ? species; Assemblage 2, well diversified but with low abundance; and Assemblage 3, with cold water ostracods such as Krithe . Based on the ostracod assemblages identified, a middle neritic, platformal paleoenvironment was inferred for the studied interval. [ABSTRACT FROM AUTHOR]

The structural framework and tectonic evolution of the sedimentary basins along the eastern margin of the South American continent are closely associated with the tectonic framework and crustal heterogeneities inherited from the Precambrian basement. However, the role of NW-SE and NNW-SSE structures observed at the outcropping basement in Southeastern Brazil and its impact over the development of those basins have not been closely investigated. In the continental region adjacent to the Campos Basin, we described a geological feature with NNW-SSE orientation, named in this paper as the Alegre Fracture Zone (AFZ), which is observed in the onshore basement and can be projected to the offshore basin. The main goal of this work was to study this structural lineament and its influence on the tectonic evolution of the central portion of the Campos Basin and adjacent mainland. The onshore area was investigated through remote sensing data joint with field observations, and the offshore area was studied through the interpretation of 2-D seismic data calibrated by geophysical well logs. We concluded that the AFZ occurs in both onshore and offshore as a brittle deformation zone formed by multiple sets of fractures that originated in the Cambrian and were reactivated mainly as normal faults during the rift phase and in the Cenozoic. In the Campos Basin, the AFZ delimitates the western side of the Corvina-Parati Low, composing a complex fault system with the NE-SW faults and the NW-SE transfer faults. [ABSTRACT FROM AUTHOR]

Post-collisional reversely zoned plutons occurring in the Araçuaí belt frequently show basic cores enveloped by felsic rocks, with intense magma mingling/mixing features. The Venda Nova (VN) pluton presents, in addition to its mafic core composed of gabbronorites surrounded by syenomonzonites, a narrow ring of charnockite and norite. The VN is considered as a marker of the last magmatic phases of the Araçuaí orogenic collapse and bears one of the few high-quality Cambrian paleomagnetic data for the West Gondwana, but no geochronological data is yet available for it. In this paper, we report new in-situ U-Pb geochronological data (SHRIMP II) for the syenomonzonite, gabbro and charnockite of the Venda Nova pluton. These data are discussed and compared to the geochemical and geochronological data available for the post-collisional magmatic rocks of the Araçuaí orogen. The concordant ages of the syenomonzonite (496.9 ± 4.2 Ma, MSWD = 0.0019, n = 14) and gabbro (500.6 ± 3.7 Ma, MSWD = 0.0290, n = 14) are likely the crystallization age of the main plutonic body and corroborate the previous interpretation of paleomagnetic data. In contrast, two age groups were identified for the charnockite: Group I (n = 14, 624.0 ± 3.1 Ma, MSWD = 0.116), which includes zircon borders and rims without evidence of border reaction, and Group II (n = 6, 483.7 ± 7.4 Ma, MSWD = 0.0003) from zircon grains with luminous rims and older cores. Since the Venda Nova charnockite has (i) a distinct geochemical signature compared to other post-collisional charnockite bodies found in the same region, (ii) higher magnetic anisotropy degrees compared to other border units of the same intrusion, and (iii) marked sub-solidus deformation features, the Group I ages are suggested as the crystallization age of these rocks, while Group II ages would be better interpreted as a resetting due to the thermal influence of the syenomonzonite and gabbro intrusions. This implies that the VN is a composite magmatic complex with contributions of magmas from the pre-collisional magmatic arc and from the post-collisional melts originated in the crust and mantle across the Araçuaí lithosphere during orogen collapse. • The Venda Nova (VN) is a reversely zoned pluton in the Araçuaí orogen (AO, Brazil). • U-Pb data from syenomonzonites, gabbros and charnockites is provided. • Syenomonzonites (496.9 ± 4.2 Ma) and gabbros (500.6 ± 3.7 Ma) date the post-collisional event of the AO. • Charnockites are suggested to be far older (624.0 ± 3.1 Ma) and part of a pre-collisional setting. [ABSTRACT FROM AUTHOR]

The eastern portion of the Dom Feliciano Belt in southernmost Brazil, known as Pelotas Terrane, is composed of Neoproterozoic rocks presenting metamorphic xenoliths in granitoid rocks, described and interpreted as "basement inliers". Based on novel petrographic, mineral/whole rock/Sr–Nd geochemistry and U–Pb geochronological data, this paper presents the first record of a Paleoproterozoic metagabbro xenolith in the Pelotas Terrane. The studied xenolith exhibits a sharp and angular contact with the host rock and a predominant granoblastic texture, with sub-vertical mm-to cm-thick metamorphic banding, marked by the felsic and mafic bands, composed respectively of bytownite (An 85) ± quartz, and diopside ± tremolite ± epidote. Zircon, apatite, and iron/titanium oxides occur as accessory minerals. The peak metamorphism for this rock is estimated at amphibolite facies conditions. The whole-rock chemistry of the metagabbro suggests a basic derivation (e.g., SiO 2 52 wt%; Al 2 O 3 12 wt%; Ni 33 ppm). The spidergrams demonstrate high LILE and HFSE concentrations. Chondrite-normalized REE patterns show enrichment in LREE. The Sr–Nd isotopic data show 87Sr/86Sr (i) = 0.701024, εNd (i) = 5.44, and Nd-T DM = 2.1 Ga. The metagabbro yielded a U–Pb Concordia age with analytical points arranged in a Discordia line. The upper intercept was interpreted as a magmatic crystallization age of 2.1 Ga (zircon cores), and the lower intercept indicated a resetting age of 616 Ma (zircon rims). The obtained Archean age (2.8 Ga) is interpreted as inherited. Gabbro's metamorphism likely reached the amphibolite facies, elemental and isotopic geochemistry. The remote zircon inheritance of xenoliths that have had polycyclic survival is used to link the occurrence of a gabbro xenolith, in the Pelotas Terrane (Dom Feliciano Belt; Southern Brazil), whose magmatic crystallization age is Paleoproterozoic, with the basement terranes before the Namaquan orogeny, in the Rehoboth region (Gariep Belt and Bushmanland/Namaqualand; Namibia). These units could be related to the evolution of an ancient Paleoproterozoic magmatic arc formed by the convergence of two Archean continents during the evolution of the Atlantica Supercontinent. [Display omitted] • First magmatic record of Paleoproterozoic rock in eastern Dom Feliciano Belt. • Metagabbro xenolith with 87Sr/86Sr (i) = 0.701024, εNd (i) = 5.44, Nd-T DM = 2.1 Ga. • Magmatic arc-related rock linked to the Rehoboth Basement Inlier, Africa. • An important piece in the West Gondwana assembly. [ABSTRACT FROM AUTHOR]

This paper provides a new technique for evaluating lineaments that focuses on the spatial link between surface and subsurface elements in a single layer. We chose a test area in northeast Brazil's Borborema Province. We extracted magnetic and relief lineaments from aeromagnetic and SRTM data. We defined the lineaments that agree on both layers using GIS operations. To identify the concordance between lineaments, we constructed kernel density maps that combined the data from each layer. We detected NE-SW solid conditioning of the structures. Even when evaluating only the concordant lineaments in other directions, they are expressed in groupings in NE-SW, as with NW-SE features, that associates with transfer failures and are contained by large NE-SW structures. The Atlantic Ocean's opening and expansion phases were linked to the E-W direction, also truncated by NE-SW lower density sections. The N–S trend was inexpressive. Areas with a higher density of concordant lineaments were associated with regions more susceptible to the Neotectonics of landform inversion, forming domes and arches-oriented NE-SW, as in Serra do Mel, Macau High, and Ponta Grossa High. Lower lineament density areas indicated visual correspondence with the most significant number of production wells in the Potiguar Basin, indicating that these regions are more favorable for the accumulation and trapping of hydrocarbons. • Lineaments from various sources may be combined to form a single data layer. • Deep NE-SW structures influence the relief disposal in the Potiguar Basin. • Zones limit geological sectors with a lower density of concordant lineaments. • Higher density of concordant lineaments zones are more prone to Neotectonic uplift. • The lower density of concordant lineaments correlates with oil exploration wells. [ABSTRACT FROM AUTHOR]

Opportunities to examine the structure of paleocommunities are extremely rare, due to the incompleteness of the fossil record. Regarding the Morro do Chaves Formation, there are many studies about the fauna and flora since 1870. However, paleoecological data are relatively scarce. According to the most recent study, the palynological records of the Morro do Chaves Formation were related to a disturbed paleoenvironment, caused by marine incursions in the northern sector of the Sergipe-Alagoas Basin during Lower Cretaceous. Thus, this paper aims to analyze the paleoecological relationships of the paleocommunity of fishes in the Morro do Chaves Formation, as the possible responses to the paleoenvironmental disturbances. From the basic matrix of abundance data for four fish orders found in 11 pelitic levels, similarity matrices were computed, using the Bray-Curtis distance coefficient. Cluster analysis by the unweighted pair-group method using arithmetic averages (UPGMA) was performed on these matrices, for grouping the levels. The advantages of multivariate analysis in paleoecological studies are also discussed. In addition, the Morro do Chaves Formation is composed of active piscivorous predators, benthophagous and planktiphagous fishes. The aulopiform fishes probably acted as top-down regulators in the paleocommunity, controlling the local fish populations. Mawsonia and " Lepidotes " are usually recorded in similar outcrops and inferred to be associated fauna. While Mawsonia likely possesses a sit-wait strategy, " Lepidotes " would be a relatively more active predator. • " Lepidotes " and Mawsonia are usually found together. • Aulopiformes, acted in the maintenance of the paleoichthyofauna. • " Lepidotes " would be relatively more active than Mawsonia. • Mawsonia could return to the marine environments. • The Morro do Chaves Formation was a constantly disturbed paleoenvironment. [ABSTRACT FROM AUTHOR]

Souza and Perez Filho (2019) inferred two transgressive events in the Late Holocene record of lower Ribeira de Iguape River and Ilha Comprida barrier, Southeastern Brazil, based on luminescence ages and paleoenvironmental interpretation of four columnar sections. In the present paper, we discuss inconsistencies on the methods applied and sample design adopted by those authors, which lead to an incorrect model of coastline evolution for the region over the time period covered by the dates obtained. The dataset presented by Souza and Perez Filho (2019) allows the reinterpretation of the deposits studied as regressive and fits into previous models of regional coastal evolution. • We discuss methods inconsistencies and sample design adopted by the original study. • OSL ages were reinterpreted and fit into previous regional coastal evolution models. • No regional transgressive events were observed during the Late Holocene. [ABSTRACT FROM AUTHOR]

The migration of transgressive coastal dunes over urban and farming areas is commonly observed in the semi-arid northern coast of the Brazilian northeast. However, it is unusual in the humid tropical coast of southeastern Brazil. This paper aims to investigate the aeolian dynamics and the drivers of the burial process over the Itaúnas District, Espírito Santo State landscape, by transgressive coastal dunes. Methodological procedures consist of remote sensing techniques, geoprocessing, wind regime simulations, and mathematical calculations of migration rate parameters. Satellite images were georeferenced using ArcGIS 10.3 software and wind regime information was simulated using HYSPLIT software using wind reanalysis data. The results suggest a sediment transport rate of 44.98 kg/m/s, wind drift potential of 123.96 v.u. and dune migration rate estimated at 4.0 m/yr. It was found that the northern and western sectors of the studied dunefield have the highest migration rates towards the main access road, water resources and urban area. The values obtained are considered significant because it is a coastal segment subjected to a humid tropical climate. • New data on the burial process by moving dunes over Itaúnas District, Brazilian Southeast, are presented. • It is suggested that the cause of the burial process is associated with deforestation of beach ridge by human activity. • Obtained results suggest a dune mobility rate of 4.0 m/year. • Results obtained suggest a sediment transport rate in the order of 44.98 kg/m/s and a wind drift potential of 123.96 v.u. [ABSTRACT FROM AUTHOR]

The visualization, analysis and interpretation of sedimentary data can be optimized with techniques such as the Digital Outcrop Models (DOMs) generated with the Structure from Motion – Multi-View Stereo (SfM-MVS) technique. In this paper, to demonstrate the usage of DOMs in the characterization of the depositional architecture of a braided fluvial system, we developed a case study in Jaicós Formation, Parnaíba Basin, NE Brazil, where a high-resolution stratigraphic analysis of a braided fluvial system was performed, and the potentials and limitations of the method were evaluated. This multi-scale reservoir analysis allowed the identification, description and interpretation of facies, bounding surfaces and architectural elements. In addition, it was also possible to predict quantitative attributes of the fluvial system that deposited this sequence and evaluate the potential of this formation as a reservoir. • The usage of Virtual Outcrop Models in High Resolution Stratigraphy. • Analysis of facies, bounding surfaces and architectural elements. • Quantitative estimation of the fluvial system that deposited Jaicós Formation. [ABSTRACT FROM AUTHOR]

Inverted metamorphic gradients are recognized in several Proterozoic to Phanerozoic orogens. However, the mechanisms that are responsible for the formation of these gradients are still a matter of discussion. In the southern Brasília Orogen, an inverted metamorphic gradient is recorded in the Passos Nappe, that comprises a sequence of metasedimentary rocks with minor intercalations of tholeiitic metamafic rocks, metamorphosed under greenschist facies (biotite zone) at the bottom and high-pressure granulite facies at the top. This paper presents a detailed investigation of pressure and temperature conditions along the Passos Nappe by integrating conventional geothermobarometry in metamafic rock and single-trace elements geothermometry (Zr-in-rutile and Ti-in-quartz) in quartzite. Nine lithostratigraphic units are identified in the Passos Nappe, which are informally named A to I, from the bottom to top, adding up to a minimum thickness of 4.56 km. In mafic rocks, the increase of metamorphic conditions is indicated by: (1) chemical variation of amphiboles, from actinolite/edenitic hornblende in Unit C, to pargasitic hornblende in Units E and G, and Fe-pargasite in Units H and I; (2) plagioclase composition varying from An1-13 in Unit C, An15-27 in Unit D to andesine at upper units; and (3) occurrence of clinopyroxene from the top of Unit E upwards. Additional petrographic features in quartzite also corroborate these insights, such as: the increase of grain size of both quartz and rutile, from bottom to top; the morphology of rutile crystals; the mechanism of quartz recrystallization (subgrain rotation dominates in lower units while grain boundary migration dominates in upper units) and the occurrence of rutile needles in quartz in the upper units, which suggest a continuous gradient. Combined application of Zr-in-rutile and Ti-in-quartz geothermometers in quartzite provided the following average temperature and pressure values for each unit: 673 °C and 11.7 kbar for Unit E, 690 °C and 9.5 kbar for Unit G, 747 °C and 11.6 kbar for Unit H and 758 °C and 11.3 kbar for Unit I. Our data indicate that the Zr-in-rutile and Ti-in-quartz systems do not re-equilibrate in metamorphic conditions lower than 600 °C. The extrapolation of these results to the low-grade units indicate: 496 °C and 4.8 kbar at Unit A, 504 °C and 4.8 kbar at Unit B, 502 °C and 4.4 kbar at Unit C. The results obtained with the geothermometer hornblende-plagioclase and the geobarometer garnet-rutile-ilmenite-plagioclase-quartz in metamafic rocks yielded the following average values for each unit: 486 °C and 5.0 kbar at Unit C, 568 °C and 6.0 kbar at Unit D, 622 °C and 8.1 kbar at Unit E, 650 °C and 8.4 kbar at Unit G, 743 °C and 9.4 kbar at Unit H and 723 °C and 11.2 kbar at Unit I. Since the two geothermobarometric approaches are based on independent chemical systems, the results obtained represent robust estimates for the temperature and pressure conditions for the inverted metamorphic gradient of the Passos Nappe. Comparing the inverted metamorphic gradient at the Passos Nappe with classical occurrences at the Himalaya Orogen, it is possible to assume that both origins were similar, which probably involved isotherm inversion due to subduction, channel flow process associated with shear heating and transport of higher pressure rocks over low-pressure rocks by reverse ductile shearing. • Characterization of the inverted metamorphism at the Passos Nappe (SW, Brazil), by combining multiple geothermobarometers. • Geodynamic processes that could produce inverted metamorphic sequences in orogenic systems. • Correlation between tectonostratigraphic dominant in the Southern Brasília Orogen. [ABSTRACT FROM AUTHOR]

Tanks are natural, mostly elliptic depressions formed in the igneous or metamorphic basements of northeastern Brazil. The taphonomy of the fossil vertebrate assemblages preserved in tank deposits has been intensely studied. However, so far the focus was mainly on biostratinomic aspects. This paper presents a diagenetic analysis of megafauna bone thin sections from four tank deposits in northeastern Brazil, the interpretation of their diagenetic histories and a comparison between the sites. The geographic proximity of the sites and their similar paleoclimatic settings were the likely factors responsible for the similarities observed among the thin sections of different tank deposits. In contrast, some striking differences resulted from the particular characteristics of the areas in which the tank deposits are located, most notably the local geological settings and their distances from nearby drainages. Comparisons with other studies showed that the availability of water and conditions that favored permineralization were common in northeastern Brazil during the Quaternary. Finally, diagenetic contrasts among bones thin sections from the same tank evidence temporal mixing in the vertebrate accumulations within these natural-trap deposits. • Tank deposits in Northeastern Brazil experienced similar diagenetic histories. • The chemistry of surface waters strongly influenced the fossildiagenesis. • A possible paleocurrent was proposed for the Riacho Verde Tank. • Comparisons indicate permineralization as a favored process during the Quaternary. [ABSTRACT FROM AUTHOR]

Potential-field edge detection filters are powerful fault detection tools in mineral exploration. The application of these filters to electromagnetic (EM) data is not as accepted as those associated with potential field data. But they may be advantageous when dealing with mineralizations associated with non-magnetic rocks. This paper introduces the multiscale edge detection filter to provide an enhanced image of fault zones when applied to apparent conductivity data. The Rio das Velhas Greenstone Belt, the studied area, hosts several gold mineralizations controlled by northwest–southeast shear zones subparallel to non-magnetic metasedimentary rocks that are typical candidates for the EM interpretation. Several northwest–southeast trending faults were highlighted in the studied area. We employed a data fusion interpretation strategy by correlating the detected EM faults with radiometric anomalies to classify high-priority spots for future exploration. We tagged four known gold deposits and new targets with similar characteristics following the proposed guidelines. • We show that the multiscale filter (worming) can be used for electromagnetic (EM) data. • The EM worming screened non-magnetic mineralized fault zones in the Rio das Velhas Greenstone Belt. • Combining EM-worming and radiometric data, we selected sites for follow-up surveys. [ABSTRACT FROM AUTHOR]