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The study of disarticulated ossicles of recent sea cucumbers from Campos Basin, Rio de Janeiro, Brazil, from various Holocene strata, obtained by micropaleontological methods, resulted in the identification of at least eight holothurian taxa, belonging to the five of the seven orders of Holothuroidea: Apodida (Synaptidae, Chiridotidae), Dendrochirotida (Psolidae and Cucumariidae), Holothuriida (Holothuria), and Molpadiida (Molpadiidae, Eupyrgidae). Our paper endorses the importance of studies of recent fauna based on isolated ossicles for taxonomy, biostratigraphy, and ecology. This study represents the first effort at the study of recent fauna of sea cucumbers based on the analysis of preserved ossicles in marine sediments. [ABSTRACT FROM AUTHOR]

This paper discusses data from the pioneering and the latest research in Serranópolis, Goiás, Brazil. It focuses on subjects such as landscape, mobility, territoriality, distribution of rock art sites, lithic material, anthropic action, and natural processes as elements that impact archaeological sites. The approach includes the hunter-gathering groups from the Itaparica (Paranaíba Phase) and Serranópolis (Serranópolis Phase) Traditions from Upper to Middle Holocene, which are characterized by their set of lithic artifacts. Therefore, some data resulting from research that took place between 2000 and 2020 by several researches were included in the previous study from 1980 to 2000 by Schmitz and his crew. The key element is the landscape analysed within a multidsciplinary approach through the Landscape Archaeology. This paper emphasizes some subjects that must be reanalyzed through current techniques and sustains that new excavations need to take place with a special attention to the relation between the landscape and the data developed under a geoarqueological point of view. [ABSTRACT FROM AUTHOR]

Integration of late Quaternary continental and marine proxies allows improved reconstruction of palaeoenvironment and palaeoclimates models for the south-eastern coast of Brazil. In this paper, we analyse pollen, fern spores, and dinoflagellate cysts in a marine sediment core (GL74) over the last ∼109 kyr. Results showed that, between 109 and 89.5 kyr, low sea levels promoted the expansion of herbaceous taxa across open areas while climatic conditions were relatively warm and humid, as indicated by the high frequency of Atlantic rainforest Ombrophilous forest pollen types and abundant of fern spores. Between ∼79–49 kyr, higher concentrations of palynomorphs were recorded, which were likely related to the low relative sea level during the last glacial period. During this interval, there was a decrease in tree pollen grains and an increase in shrub and herbaceous pollen grains, indicating cold and relatively dry weather conditions. In the Holocene period, the low deposition of palynomorphs may have been influenced by the gradual submergence of the central part of the Brazilian coast. This process was associated with warm and humid climatic conditions, as suggested by the expansion of rainforests and the presence of hygrophyte/aquatic taxa and fern spores, as well as the retraction of grassland pollen types. Dinocyst assemblages suggest that nutrient-rich waters and/or the presence of upwelling cells were dominant between ∼109–88 kyr, but gradually reduced between 88 and 65 kyr (and/or ∼ 88–20 kyr) under the influence of subtropical fronts. The study culminated in the dominance of unproductive warm water in the upper column between 65 and 0.5 kyr. • Correlation of continental and marine proxies in south-eastern Brazil during the late Quaternary Late • Quaternary dynamics of the South Atlantic Ocean based on dinocysts • Reconstruction of palaeovegetation and palaeoclimate for the last ∼109 kyr along the southeast coast of Brazil [ABSTRACT FROM AUTHOR]

This paper discusses a model of coastal barrier progradation where the development of a prograded plain was a product of the successive formation of foredune ridges followed by their burial by transgressive sand sheets and dunefields. The results are based on direct lithological data from drill holes and geomorphological analyses, indirect geophysical data (GPR), and 14C and OSL dating. Barrier progradation started at 6.69 ka (OSL) or 7.2 ka (14C), under sea-level rise. At around 5.0 ka (OSL), or thereabouts, a forced regression condition started to operate, when sea-level started to fall after it reached a maximum of 2.34 ± 0.8 m. During barrier progradation sets of foredunes were formed, and at least some of them were buried by sands of transgressive dunefields (TDF), which later evolved to transgressive sand sheets (TSS). A total of 11+ phases of TSS and a modern phase of TDF were formed in a time span of 6.69 ka (OSL) or 7.2 ka (14C), corresponding to one phase formed at each 560 or 600 yrs. Two models of possible development of the surface of Curumim barrier are proposed. • Arare record of aforedune plain buried by transgressive sandsheets formation. • The cyclic formation of transgressive dunefieldsand transgressive sand sheets. • The foredune/beach contact as a proxy of sea-level position. • Distinct contributions of normal and forced regressionon barrier progradation. • Possibletransformation of a transgressive dunefield in a transgressive sand sheet. [ABSTRACT FROM AUTHOR]

Northeastern Brazil has thousands of wetland fossiliferous deposits with megafauna and, in some cases, associated lithic artifacts. The timing of the arrival of humans in South America and the extinction of megafauna is still debated and these sites contribute both to this discussion and to the reconstruction of the Late Pleistocene and Holocene paleoenvironment. Lagoa do Quari, 40 km south of São Raimundo Nonato, Piauí state, is a marsh deposit in the present semiarid caatinga environment, excavated by an interdisciplinary team in 2002–2003. This paper presents the archaeological, palaeontological, geological, chronological, stratigraphical and palynological results and their implications for the Quaternary of northeastern Brazil. The site has a rich megafaunal bonebed at the bottom, dominated by Eremotherium giant sloth remains with poor biodiversity, and a sandy‐silty deposit at the top; two 14C dates constrain this latter layer to 9,944–9,557 and 6,308–6,177 cal. years BP and the associated rich lithic industry of quartz and chert shows a technical continuity throughout the Holocene in the region. Palynology describes an open landscape with periodic wet phases, which could explain the richness of the archaeological occurrences in Holocenic Brazilian prehistory. This study offers a model of interdisciplinary enquiry into the paleoenvironment and prehistory of lowland South America. [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]

This paper focuses on high-resolution coastal stratigraphy data, which were revealed by the Ground Penetrating Radar (GPR) system. Surveys performed with GPR on the surface of prograded barriers reveal patterns of reflections that allow the interpretation of the geometry and stratigraphy of coastal deposits in a continuous mode. At the Curumim prograded barrier in southern Brazil (29°30′ S–49°53′ W), a two-dimensional transverse GPR survey revealed, with high precision, a serial of contacts between aeolian deposits of relict foredunes and relict beach deposits that have a strong correlation with sea level. In a 4 km GPR profile, a total of 24 of these contacts were identified. The high accurate spatial positioning of the contacts combined with Optical Stimulated Luminescence dating resulted in the first confident sea-level curve that tells the history of sea-level changes during the last 7 ka on the southernmost sector of the Brazilian coast. The curve shows that sea-level was still rising before 6 ka BP, with a maximum level of 1.9 m reached close to 5 ka BP; after that, sea-level started to falling slowly until around 4 ka BP when fall accelerated. [ABSTRACT FROM AUTHOR]

This paper analyzes the sedimentary record of a paleo-inlet that evolved in association with a coastal barrier, using data that provides a high-resolution stratigraphy. During the evolution of the Guaratuba Holocene barrier, autogenic factors associated with the paleo-estuary dynamics compete with allogenic factors of RSL (Relative Sea Level) variation and the influence of climate on sediment input. The integration of geological mapping, vibrocore, GPR (Ground Penetrating Radar), and radiocarbon dating techniques allowed for recognizing of a paleo-inlet migrating east-southeast during the turning point between the transgressive and regressive stages, cyclically affected by episodes of aggradation and reversal in the direction of lateral migration. This dynamic, conditioned by shadow zones of bedrock elevations and the littoral drift of sediments, modifies the stratigraphy and the barrier's depositional architecture, defining diachronous surfaces and lateral variations in the stratigraphic stacking. These features exemplify how barrier-inlet systems are affected by the combination of high frequency, climate-defined events and local coastal processes during their evolution. • Coastal barrier stratigraphy reveals paleo-inlet migration during Holocene sea level rise. • Autogenic and allogenic factors shape barrier-inlet systems during evolution, forming diachronous surfaces. • Barrier progradation and spit/inlet migration characterized by radarfacies, radiocarbon ages, and sedimentary facies. [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]

Studies dealing with the reconstruction of Holocene climate change of tropical areas are scarce. Of these, multi-proxy investigations using peatlands are still absent. In this paper, we present the Holocene record of environmental changes in central–eastern Brazil reconstructed from a core sampled in Pau de Fruta mire (Serra do Espinhaço Meridional, Brazil). We combined palynological and geochemical analyses, supported by core stratigraphy, 14 C dating and multivariate statistics. The location of the mire is ideal because it is in an area which is directly associated with the South Atlantic Convergence Zone (SACZ). Six main phases of change suggested by vegetation and local and regional landscape dynamics were described. In phase I (~ 10,000–7360 cal. yr BP) the climate was very wet and cold and was accompanied by soil instability in the mire catchment (severe local erosion) and the 8.2 ka event was easily recognizable by a large increase in the deposition of regional dust. Phase II (~ 7360–4200 cal. yr BP) was characterized by wet and warm conditions, catchment soil stability and enhanced deposition of regional dust. In phase III (~ 4200–2200 cal. yr BP), climate was dry and warm and soil erosion in the catchment increased again. In phase IV (~ 2200–1160 cal. yr BP) dry and punctuated cooling was reconstructed, together with enhanced deposition of regional dust. Phase V (~ 1160–400 cal. yr BP) reflects sub-humid climatic conditions (like the current climate), the lowest inputs of local and regional dust and the largest accumulation of peat in the mire. While in phase VI (< ~ 400 cal. yr BP) sub-humid conditions continued but both local and regional erosion significantly increased. Our results demonstrate that the tropical peatlands of Serra do Espinhaço Meridional contain relevant records of Holocene climate changes, and that a multi-proxy approach offers good opportunities for a detailed reconstruction of palaeoenvironments. [ABSTRACT FROM AUTHOR]

This study presents spatiotemporal paleo-sea-level reconstructions from Abrolhos archipelago and Abrolhos Bank, and fill in a coastline gap of 500 km where no precise paleo-sea level reconstruction exists. The reconstructions are based on sedimentary, biological and geomorphological evidences. The data indicates sea-levels up to 2.9 m higher than the current one between the Mid- to Late Holocene, in agreement with the empirical sea-level envelope and with predictions of geophysical sea-level models for the Brazilian coast. The data suggests that there was little, if any, hydroisostatic compensation across 55 km of the continental shelf in the study area, between the archipelago and the mainland coast, given that similar elevations of the post-glacial sea-level maximum exist in both places. • Broken and tilted coral pinnacles on Abrolhos Bank that can be misleading evidence of higher Holocene sea levels. • This paper presents paleo-sea level reconstructions at Abrolhos Archipelago, located 55 km away from Brazilian mainland. • The reconstructions indicate Holocene paleo-sea levels between 3.1 m and 2.5 m above present one. • The reconstructions are in agreement with predictions of sea-level models and with empiric data for mainland Brazilian coast. • The reconstructions are contradictory with recently published paleo-sea levels from the same area. [ABSTRACT FROM AUTHOR]

The biological variation of the earliest skeletons of South America has been intensely debated for the last two centuries. One of the major research constraints has been the limited number of available samples dating to the early Holocene. We here present the first direct radiocarbon-date for the early Holocene human skeleton from Toca dos Coqueiros (Serra da Capivara, Brazil), also known as "Zuzu" (8640 ± 30 BP; 9526–9681 cal years BP). We performed craniometric analyses using exclusively samples from Brazil, to revisit the sex of the skeleton, and to discuss the evolutionary processes involved in the occupation of the continent. The sex of the individual was estimated as a female when compared to late and early Holocene individuals, but as a male when compared only to the early Holocene series. We also found that Zuzu presents the strongest differences with the late Holocene Guajajara individuals, located nearby, and the strongest similarities with the early Holocene series from Lagoa Santa, attesting for solid biological affinities among early Holocene individuals from Brazil, as well as a moderate level of morphological variation among them. This suggests that the early individuals were part of the same heterogeneous lineage, possibly a different one from which late Holocene populations diverged. [ABSTRACT FROM AUTHOR]

The classic models of cuesta evolution in south‐eastern Brazil have temporal gaps in their denudation chronology. Here, we analyzed the colluvial deposits located on the rim of the Serra Geral escarpments in the Paraná Basin to propose a model with an absolute age range of minor landform evolution within this cuesta morphology. Correlation of the optically stimulated luminescence ages with the regional paleoclimatic conditions demonstrates that the successive phases of colluviation reflect either short‐term intervals of variability in moisture availability or dry periods in the Holocene. The potential effects of other contributing factors (vegetation changes, local geomorphic settings and human activity) add complexity to the denudation responsible for the development of the investigated geomorphic chronosequences. The proposed model consists of five stages of hillslope sediment remobilization that were responsible for further remodeling of the minor vertical steps during the following chronological distribution: (i) 9.13 ± 1.2–7.09 ± 0.96 ka; (ii) 5.66 ± 0.86–4.5 ± 0.75 ka; (iii) 3.94 ± 0.605–3.45 ± 0.6 ka; (iv) 2.66 ± 0.315–2.3 ± 0.4 ka; and (v) after 1960 to the present day. [ABSTRACT FROM AUTHOR]

Speleothems can provide high-quality continuous records of the direction and relative paleointensity of the geomagnetic field, combining high precision dating (with U-Th method) and rapid lock-in of their detrital magnetic particles during calcite precipitation. Paleomagnetic results for a mid-to-late Holocene stalagmite from Dona Benedita Cave in central Brazil encompass ~1900 years (3410 BP to 5310 BP, constrained by 12 U-Th ages) of paleomagnetic record from 58 samples (resolution of ~33 years). This dataset reveals angular variations of less than 0.06° yr−1 and a relatively steady paleointensity record (after calibration with geomagnetic field model) contrasting with the fast variations observed in younger speleothems from the same region under influence of the South Atlantic Anomaly. These results point to a quiescent period of the geomagnetic field during the mid-to-late Holocene in the area now comprised by the South Atlantic Anomaly, suggesting an intermittent or an absent behavior at the multi-millennial timescale. The South Atlantic Anomaly has the lowest intensity of the geomagnetic field. A stalagmite, from Brazil shows through its magnetic remanence that in mid-to-late Holocene this anomaly, was not being expressed or recurrent at surface in millennial scale. [ABSTRACT FROM AUTHOR]

Abstract: Continental shelves have the potential to remove atmospheric carbon dioxide via the biological pump, burying it in seafloor sediments. The efficiency of marine carbon sequestration changes rapidly due to variations in biological productivity, organic carbon oxidation, and burial rate. Here we present a high temporal resolution record of marine carbon sequestration changes from a western South Atlantic shelf site sensitive to Brazil Current-driven upwelling. The comparison of biological records to rare earth element (REE) patterns from authigenic oxides shows a strong relationship between higher biological productivity and stronger particle reactive element cycling (i.e. REE cycling) during rapid climate change events. This is the first evidence that authigenic oxides archive past changes in upper ocean REE cycling by the exported organic carbon. In addition, our data suggest that Brazil Current-driven upwelling varies on millennial-scales and in time with continental precipitation anomalies as registered in Brazilian speleothems during the Holocene. This indicates an ocean–atmosphere control on the biological pump, most probably related to South American monsoon system variability. [ABSTRACT FROM AUTHOR]

The emergence of plant-based economies have dominated evolutionary models of Middle and Late Holocene pre-Columbian societies in South America. Comparatively, the use of aquatic resources and the circumstances for intensifying their exploitation have received little attention. Here we reviewed the stable carbon and nitrogen isotope composition of 390 human individuals from Middle and Late Holocene coastal sambaquis, a long-lasting shell mound culture that flourished for nearly 7000 years along the Atlantic Forest coast of Brazil. Using a newly generated faunal isotopic baseline and Bayesian Isotope Mixing Models we quantified the relative contribution of marine resources to the diet of some of these groups. Through the analysis of more than 400 radiocarbon dates we show that fishing sustained large and resilient populations during most of the Late Holocene. A sharp decline was observed in the frequency of sambaqui sites and radiocarbon dates from ca. 2200 years ago, possibly reflecting the dissolution of several nucleated groups into smaller social units, coinciding with substantial changes in coastal environments. The spread of ceramics from ca. 1200 years ago is marked by innovation and intensification of fishing practices, in a context of increasing social and ecological instability in the Late Holocene. [ABSTRACT FROM AUTHOR]

The coastal plain of southern Brazil documents several environmental changes mainly related to sea-level fluctuation and climatic variations during the Quaternary. Comprehensive studies have been carried out, of local and regional scope, in order to improve the knowledge about the geological evolution of this portion of the South American. In this paper we present the results of stable isotope, palynological and palynofaciological analysis of the PSC-03 core (7744 cal yr BP – Modern) was performed to provide the sedimentary evolution of the Santa Catarina coastal plain. Palynological and palynofacies analyses revealed abundant and diversified palynological associations, including terrestrial palynomorphs (spores, pollen grains, fungi, and freshwater algae), marine elements (dinoflagellate cysts and foraminiferal linings), besides abundant phytoclasts and amorphous organic matter. Based on the combined analysis of δ13C isotopes (−20.7 ‰ to −29.6 ‰) and the C/N ratio (15.5–68) of the selected samples, we deduce that the organic matter is derived from marine phytoplankton and terrestrial C 3 plants. The integrated approach of palynofacies and stable isotopes (δ13C and C/N) analyses revealed three distinct intervals, which characterize the environmental evolution of this portion of the coastal plain. The Interval I (7744 to 2844 cal yr BP) is related to a marginal marine environment, followed by the Interval II (2857 to 2276 cal yr BP), which indicates shallow water conditions, with wetland or soggy soils, while the Interval III (2124 cal yr BP to Modern) shows a subaerial scenario, strongly influenced by arboreal forms of the Atlantic Forest. Comparisons with other sites in southeastern South America were carried out, especially from Uruguay and Argentina, showing similarities in the palynological succession, as response to broader climatic conditions. • Stable isotopes (δ13C and C/N) and palynofacies analyses are used for understanding coastal evolution of southern Brazil. • Three paleoenvironmental phases are identified within the last 7744 cal years BP. • The marine influence is evidenced between 7744 and 2884 cal years BP. • Major development of the Atlantic Forest in the area from 2124 cal years BP onwards. [ABSTRACT FROM AUTHOR]

Multiproxy approach based on textural, mineralogical, geochemical, and microfaunal analyses on a 176-cm-long core (SP8) has been applied to reconstruct the Holocene paleoenvironmental changes and disentangling natural vs. anthropogenic variability in Marambaia Cove of the Sepetiba Bay (SE Brazil). Sepetiba Bay became a lagoonal system due to the evolution and development of the Marambaia barrier island during the Holocene and the presence of an extensive river basin. Elemental concentrations from pre-anthropogenic layers from the nearby SP7 core have been used to estimate the baseline elemental concentrations for this region and to determine metals enrichment factors (EF), pollution load index (PLI), and sediment pollution index (SPI). Record of the core SP8 provides compelling evidence of the lagoon evolution differentiating the effects of potentially toxic elements (PTEs) under natural vs. anthropic forcing in the last ~ 9.5 ka BP. The study area was probably part of coastal sand ridges between ≈ 9.5 and 7.8 ka BP (radiocarbon date). Events of wash over deposited allochthonous material and organic matter between ≈ 8.6 and 7.8 ka. Climatic event 8.2 ka BP, in which the South American Summer Monsoon was intensified in Brazil causing higher rainfall and moisture was scored by an anoxic event. Accumulation of organic matter resulted in oxygen depletion and even anoxia in the sediment activating biogeochemical processes that resulted in the retention of potentially toxic elements (PTEs). After ≈ 7.8 ka BP at the onset of the Holocene sea-level rise, a marine incursion flooded the Marambaia Cove area (previously exposed to subaerial conditions). Environmental conditions became favorable for the colonization of benthic foraminifera. The Foram Stress Index (FSI) and Exp(H'bc) indicate that the environmental conditions turned from bad to more favorable since ≈ 7.8 ka BP, with maximum health reached at ≈ 5 ka BP, during the mid-Holocene relative sea-level highstand. Since then, the sedimentological and ecological proxies suggest that the system evolved to an increasing degree of confinement. Since ≈ 1975 AD, a sharp increase of silting, Cd, Zn, and organic matter also induced by anthropic activities caused major changes in foraminiferal assemblages with a significant increase of Ammonia/Elphidium Index (AEI), EF, and SPI values and decreasing of FSI and Exp(H'bc) (ecological indicators) demonstrating an evolution from "moderately polluted" to "heavily polluted" environment (bad ecological conditions), under variable suboxic conditions. Thus, core SP8 illustrates the most remarkable event of anthropogenic forcing on the geochemistry of the sediments and associated pollution loads and its negative effect on benthic organisms. [ABSTRACT FROM AUTHOR]

Modern precipitation over northeastern (NE) South America is strongly controlled by the seasonal meridional migration of the Intertropical Convergence Zone (ITCZ). Ample evidence from the Northern Hemisphere suggests a mid‐ to late Holocene southward migration of the ITCZ. Such a shift would be expected to increase precipitation over semi‐arid northern NE Brazil (Southern Hemisphere). However, the most robust precipitation record from northern NE Brazil shows a drying trend throughout the Holocene. Here, we address this issue presenting a high‐temporal resolution reconstruction of precipitation over northern NE Brazil based on data from a marine sediment core, together with analyses of mid‐ and late Holocene simulations performed with the fully coupled climate model FGOALS‐s2. Both, our data and the climate model simulations show a decrease in precipitation over northern NE Brazil from the mid‐ to the late Holocene. The model outputs further indicate a latitudinal contraction of the seasonal migration range of the ITCZ that, together with an intensification of the regional Walker circulation, were responsible for the mid‐ to late Holocene changes in precipitation over NE South America. Our results reconcile apparently conflicting precipitation records and climate mechanisms used to explain changes in precipitation over NE South America. Plain Language Summary: The tropical rainbelt impacts food and water security for 1 billion people. Knowing its dynamics is of utmost importance. The suggestion of a southward migration of the tropical rainbelt through the Holocene (last 11,700 years) has influenced paleoclimatology for two decades. However, most of the available evidence supporting this suggestion comes from tropical Northern Hemisphere precipitation reconstructions like northernmost South America. They systematically show a decrease in precipitation through the Holocene. In the tropical Southern Hemisphere like northeastern Brazil, at the opposite side of the tropical rainbelt, precipitation reconstructions are, however, rare. We reconstructed mid‐ to late Holocene (last 5,200 years) changes in precipitation over northeastern Brazil (tropical Southern Hemisphere), where modern precipitation is associated with the southern border of the tropical rainbelt. We analyzed three independent indicators of changes in precipitation recorded in marine sediments collected off northeastern Brazil. All indicators suggest a decrease in precipitation over northeastern Brazil from the mid‐ to the late Holocene. Together with climate model simulations, our results indicate a latitudinal contraction of the tropical rainbelt. A Holocene contraction of the rainbelt, in contrast to a southward migration, reconciles apparently conflicting precipitation reconstructions and provides valuable insights into the dynamics of the tropical rainbelt. Key Points: Precipitation over northern northeastern Brazil decreased from the mid‐ to the late HoloceneThe meridional migration range of the Intertropical Convergence Zone contracted from the mid‐ to the late HoloceneTogether with the intensification of the regional Walker circulation, our results reconcile previously conflicting records [ABSTRACT FROM AUTHOR]

Shell concentrations are one of the most distinctive features of the Holocene coastal stratigraphy in the southern portion of Santa Catarina State, southern Brazil. In this paper, we integrated stratigraphic, geochronological, geophysical, and taphonomic data to discuss the processes involved in the genesis of shell concentrations in a siliciclastic and subtropical setting, a useful analogy for ancient shell concentrations in semi-closed environments affected by storms. The data indicated the succession of three facies associations (FA): bay, lagoon, and back-barrier. This succession implies a grain size fining-upward trend that is representative of a gradual shallowing. Interpretation of GPR sections revealed that the passage from the bay to lagoonal deposits occurred by forming a laterally continuous, high-amplitude surface overlain by sigmoidal reflections, which characterized the progressive basinward backstepping of the lagoonal margin. Shell concentrations in bay deposits are an allochthonous product of storm flows in shallow waters. In contrast, accumulations of the bivalve Anomalocardia brasiliana had their valves reworked in the lagoonal margins and transported to the bottom, characterizing a parautochthonous accumulation. In this study, the correlation of taphonomy and grain size indicates that in bay FA, the loss of periostracum is correlated with increased gradients of fine sand, and part of the shell samples correlates to corrosion and abrasion in increased gradients of medium sand and decreased ones of fine sand. Additionally, in the lagoon FA, the loss of periostracum depends on the decrease in mud-enriched sediments and the increase in fine and medium sand, whereas brightness loss and color alteration are related to the increase in fine and medium sand, as well as margin modification. Corrosion was positively correlated to the mud-dominated fraction. • Dense concentrations of bivalve shells occur in the bay and lagoon facies association. • Allochthonous and parautochthonous bivalve shell concentrations were differentiated. • In bay FA, the loss of periostracum positively correlates to fine sand. • In the lagoon FA, corrosion was positively correlated to mud-dominated sediments. • Gradients of medium sand and fine sand correlated to corrosion and abrasion. [ABSTRACT FROM AUTHOR]

This paper reviews and integrates the knowledge about the tectonosedimentary evolution of the Resende and Volta Redonda basins (Central Segment of the Continental Rift of Southeastern Brazil), in particular the Paleogene tectonic phase. Three tectonic stages are associated to the evolution of these basins: Pre-Rift, related to the deposition of the Ribeirão dos Quatis Formation (braided fluvial); Rift I, main stage, related to the Resende Formation (braided fluvial deposits and alluvial fans associated with fault edges and intercalated basanitic volcanism); Rift II, related to the Pinheiral Formation (braided fluvial), responsible for filling the Paleogene depocenters. The post-rift sedimentation is characterized by the Neogene deposits of the Floriano Formation (meandering fluvial), as Neogene and Quaternary colluvial and alluvial deposits. The Paleogene depocenters consist of NE-SW-trending hemigrabens, with main edges to the north, in the Resende basin, and to the south, in the Volta Redonda basin. The NW-SE segmentation of the depocenters and stress propagation between the basins took place through important local and regional transfer zones. Regarding the neotectonic deformation, three brittle phases are identified: (1) Neogene transcurrent sinistral E-W-trending, responsible for the reactivation of rift faults and NE-SW segmentation of the depocenters; (2) Pleistocene-Holocene transcurrent dextral E-W-trending, responsible for the NW-SE segmentation of the depocenters and important modifications of the drainage networks; (3) Holocene NW-SE extension, responsible for the generation of important Holocene depocenters and reactivation of the rift structures. • Evolution of the Continental Rift of Southeastern Brazil in the Resende and Volta Redonda basins. • Three Paleogene tectonic stages: Pre-rift (Paleocene), Rift I (Eocene), Rift II (Oligocene). • Paleogene filling essentially by deposits of alluvial systems and basanite volcanism. • Structural styles, paleostress and 3D evolutive models of the Resende and Volta Redonda rift basins. • Neotectonic reactivation controls in the Neogene-Quaternary alluvial systems and Modern drainages. [ABSTRACT FROM AUTHOR]

The semi-arid shelf of Northeastern Brazil, adjacent to the State of Ceará, was analyzed using high-resolution seismic imaging, side-scan sonar imaging, sedimentary patterns, remotely operated vehicle (ROV), scuba dive surveys, and satellite images. Three geomorphic sectors were found according to physiographic, sedimentological, and morphological aspects: Coreaú, Mundaú, and Jaguaribe. The Ceará shelf is characterized by a mixed sedimentological pattern including a significant modern carbonate supply, relict siliciclastic grains, and a mixing of carbonates and siliciclastics. The modern siliciclastic supply is concentrated near the coast (shoreface/shoaling zone) and solid discharge from rivers is low due to a semi-arid climate. The subaqueous features (dunes, ripples, reefs, beachrocks, and incised valleys), both relict and modern, formed both as a result of sea-level changes (Wisconsin Glacial and Holocene transgression) and modern processes (longshore and wind-driven currents, waves, and tides). [ABSTRACT FROM AUTHOR]

Purpose: A skeleton named Iuzu has been unearthed from an exceptional middle Holocene burial in Toca dos Coqueiros site, in Serra da Capivara National Park (UNESCO World Heritage Site, Piauí State, Brazil). During a bioarchaeological analysis of its remains, we discovered that Iuzu was suffering from rare vertebral malformations. A double foramen transversaria, the agenesis of a foramen on the atlas and the hypoplasia of the transverse process of the axis have been highlighted. We aimed to deduce the clinical consequences of the malformation on the patient's health. Methods: We proceeded to macroscopic observation and radiography of the bones, then we search for other examples of such a pathology in archaeological litterature. Result: The malformation caused vascular insufficiency that may have led to neurological lesions leading to various pains and troubles. The very rare malformations Iuzu presented have not been found on a paleoindian skeleton from South America so far. Conclusion: This case allowed us to examine the conditions of selection of individuals buried in southern Piauí during the Middle Holocene, during which time this rite does not seem to predominate. [ABSTRACT FROM AUTHOR]

The present paper shows a GIS-based analysis for understanding the mobility system of the mound-builders (cerriteiros) of Patos and Mirim lagoons, located in southern Brazil, during the late Holocene. A geospatial model of mobility and centrality was developed using the least-cost path and network analysis methodologies. The degree of traffic and the settlement centrality allowed the interpretation of movement patterns and the connectivity of people in the coastal aquatic environment. The comparison between the terrestrial and aquatic models of mobility illustrates the permeability of the landscape suggesting the higher efficiency of movement via canoe in some environments as opposed to a purely walking-based model. Considering the GIS modeling and the archaeological and ethnohistorical data, we suggest that settlement and mobility patterns in some parts of the coastal plains were driven by the water-heavy landscape and the settlement positioning acted as mechanism of ordering the landscape. • Both waterways and land travel played a role in the mobility system of the mound builder societies of southern Brazil. • In some regions, canoeing between settlements may have been the preferred means of travel rather than overland. • The central and privileged position of some sites allowed control over the landscape, and facilitated the flow of communication in the socialnetwork. [ABSTRACT FROM AUTHOR]

Jardim, K.A.; Santos, V.F., and Oliveira, U.R., 2018. Paleodrainage systems and connections to the southern lacustrine belt applying remote sensing data, Amazon coast, Brazil. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 671–675. Coconut Creek (Florida), ISSN 0749-0208. Paleodrainage systems mapped in many regions worldwide reveal important inactive fluvial systems that indicate changes in morphosedimentary, tectonic and environmental processes in different time scales. Two paleodrainage systems were identified north of the Amazon River mouth, associated with the Southern Lacustrine Belt at Cabo Norte. The analyses were performed using data from orbital remote sensors, validated by field information and overflights. The paleodrainage systems show predominant North-South (N-S) and Southwest-Northeast (SW-NE) directions. The N-S system may be connected to an ancient Pleistocene coastline. The SW-NE system is younger, with the same direction as the current river courses and is associated with the genesis of the Araguari River. The paleodrainage alignments of this system in the Northwest-Southeast direction (NW-SE) show the same direction as tectonic lineaments presented from the basement to the continental shelf. The identified paleodrainage systems indicate significant changes in the regional drainage of the Amazonian coastal plain and indicate intense riverbed aggradation processes, which may be associated with neotectonic movements and relative sea level variations during the Quaternary. These are important indicators for the understanding of environmental changes during the Late Pleistocene and Holocene, and may aid in the paleogeographic reconstitution of the Amazon river mouth. [ABSTRACT FROM AUTHOR]

New records ofCatagonus stenocephalusandTayassu pecariare reported from the karst of Serra da Bodoquena, located at a south-western portion of Brazil near the border with Paraguay. Skull and lower jaw fragments at different stages of mineralisation were retrieved from two limestone underwater caves, Japonês and Nascente do Formoso, associated with clay and sand deposits with no retrievable stratigraphy. C14 dating of fossil mammals from these caves was attempted, but so far no success was achieved, but the inferred age for the associated paleofauna of these caves is Late Pleistocene and Holocene. The morphology of these fossil peccaries, from the most south-western known population in Brazil, is detailed and paleoecological implications are considered. [ABSTRACT FROM AUTHOR]

Since the beginning of the Holocene, hunter-gatherers have occupied the central-south Brazilian coast, as it was a very productive estuarine environment. Living as fishers and mollusk gatherers, they built prehistoric shellmounds, known as sambaqui, up to 30 m high, which can still be found today from the Espírito Santo (21°S) to Rio Grande do Sul (32°S) states, constituting an important testimony of paleodiversity and Brazilian prehistory. The chronology of the Sambaqui da Tarioba, situated in Rio das Ostras, Rio de Janeiro, is discussed herein. Selected well-preserved shells of Iphigenia brasiliana and charcoal from fireplaces in sequential layers were used for radiocarbon dating analysis. Based on a statistical model developed using OxCal software, the results indicate that the settlement occupation begun most probably around 3800 cal BP and lasted for up to 5 centuries. [ABSTRACT FROM AUTHOR]

Silva, A.L.C., Silva, M.A.M., Souza, R.S., Pinto, M.L.V., 2014. The role of beachrocks on the evolution of the Holocene barrier systems in Rio de Janeiro, southeastern Brazil. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 170-175, ISSN 0749-0208. Beachrocks at different locations along Rio de Janeiro coast (southeastern Brazil) play an important role in the understanding of coastal evolution and sea-level fluctuations in the Holocene. The studied area presents a long and wide stretch of coastal plain characterized by two sandy barriers, which confine a series of small isolated chain-like lagoons in addition to large lagoons on the reverse side of the inner barrier. The beachrocks occur at different positions in relation to present-day mean sea level. These can be observed as submarine outcrops and along the beaches. The 8.100 years old B.P. beachrocks reveal a phase of retrogradation of the barrier system, and the drowning and partial preservation of this barrier during the sea transgression through the Holocene. The beachrocks are composed of medium-to coarse sand grained bioclastic quartz-rich sandstones which are strongly cemented by calcite. Three successive events of calcite cementation have drastically reduced the porosity of the rock. Calcite cement occurs as three basic forms: isophacous fringe of very fine crystalline calcite, aphanocrystalline calcite and coarsely crystalline calcite. Each textural type indicates different geochemical composition of the pore waters during the very early diagenetic evolution within the intertidal zone of the coastal barrier system. [ABSTRACT FROM AUTHOR]

Despite the generalized occurrence of colluvial deposits in the humid tropical areas of southeastern Brazil, regional correlation is difficult because the deposits are discontinuous, and chronological data are very scarce and scattered. For the first time, colluvial deposits in the Bocaina Plateau are described, including 18 radiocarbon ages from 12 profiles. The plateau is located on the eastern flank of the Continental Rift of Southeastern Brazil and is the highest part of the Serra do Mar, with elevations up to 2000 m above sea level. Because the Bocaina Plateau is part of the summit surfaces of southeastern Brazil, it was subjected to specific climatic conditions during the Quaternary. Colluvial deposits on the lower hillslopes and edges of amphitheatres can show complex sequences with up to three intercalated dark humic horizons, corresponding to Late Pleistocene and Holocene phases of morphodynamic activity and pedogenesis. Ages of palaeosols vary from 650±50 a BP to 36 880±980 a BP. Landforms and colluvia on the Bocaina Plateau are very similar to those found on the opposite flank of the continental rift, on the Campos do Jordão Plateau. Ages of buried soils point to similar soil formation and colluviation episodes in the two plateaus. As in Campos do Jordão, the succession of erosive, depositional and pedogenetic processes on the altos campos hillslopes is probably related to late Quaternary climate changes. [ABSTRACT FROM AUTHOR]

Analysis of biological proxies in lake sediment and geochemical analysis of soil profiles reveal natural vegetation dynamics, with climate inferences, since the late Pleistocene in a fragment of the pristine lowland Atlantic Forest of southeastern Brazil. Carbon isotopes from soil organic matter and 14C ages from the humin fraction indicate the dominance of C3 plants since ~17,000 cal BP. Palynological analysis of a sediment core indicates the presence of Atlantic Forest vegetation since 7700 cal BP. Changes in the relative abundance of tree ferns and palms suggest the predominance of a humid period from ~7000-4000 cal BP and establishment of the modern seasonal climate at ~4000 cal BP. Data indicate maintenance of the regional forest coverage since the late Pleistocene, corroborating previous suggestions that this region was a forest refuge during less humid periods of the late Pleistocene and Holocene. Some plant taxa with currently divided distributions between Amazonia and the Atlantic Forest colonized the region since at least 7500 cal BP, indicating an earlier connection between Amazonia and Atlantic Forest. [ABSTRACT FROM AUTHOR]

A sediment core was studied to characterize the influences of Holocene sea-level variations in the Barra Seca River valley, in the Atlantic rainforest, Linhares, Espírito Santo, southeastern Brazil. Biological proxies (pollen, spores, and sponge spicules), 14C dating, granulometry, d13C, d15N, C/N and major chemical elements revealed the establishment and the evolution of a paleo-estuary during the interval from ~7700-585 cal BP. During the interval ~7700-7000 cal BP, the study site was occupied by a bay-head delta, the inner portion of the paleo-estuary, presenting the most dense mangrove coverage of the entire record. In the interval ~7000-3200 cal BP, the site was occupied by the central basin, possibly a consequence of the landward migration of the paleo-estuary. This interval presents reduced mangrove coverage, probably due to the permanent flooding of the valley. From ~3200 cal BP, the marine influence at the site decreased probably as result of the seaward migration of the coast line. From ~600 cal BP, the modern floodplain and freshwater lake were established. This interpretation is in agreement with the sea-level curves for the southeastern Brazilian coast, except for the fact that evidence of sea levels lower than the present at ~4000 and ~2500 cal BP as suggested by some authors were not found. [ABSTRACT FROM AUTHOR]