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Made available in DSpace on 2022-05-01T09:30:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Herein is reported the first occurrence of ostracodes from the Iapó Formation, an uppermost Ordovician unit of the Rio Ivaí Group in the Paraná basin, Brazil. Two ostracode species were identified in the Três Barras Farm section: Harpabollia harparum (Troedsson, 1918) and Satiellina paranaensis Adôrno and Salas in Adôrno et al.2016 were recovered from dropstone-bearing shale overlying glaciogenic diamictites, a feature typical of Hirnantian (uppermost Ordovician) strata throughout Gondwana. The taxonomy of the Genus Harpabollia, as well as its type species Harpabollia harparum, was reviewed, and emended and new diagnoses were respectively proposed for each taxon. Occurrences of Harpabollia harparum and Satiellina species were common in areas influenced by cold waters. Additionally, the occurrence of Harpabollia harparum, an index species to the uppermost Ordovician of several stratigraphic units in Baltica and southern Gondwana, allowed us to infer a Hirnantian age for the deposits of the Iapó Formation. Other than being associated with Harpabollia harparum in Iapó Formation of the Paraná basin, Satiellina paranaensis is also found in lower levels of the Vila Maria Formation; therefore, these are also considered Hirnantian in age. Above these lower levels of the Vila Maria Formation, a well-dated Rhuddanian (lowermost Llandovery, Silurian) palynomorph assemblage is observed within the formation. These occurrences are evidence of a continuous process of sedimentary deposition during the Ordovician-Silurian transition in the Paraná basin. Institute of Geosciences University of Brasília Center for Research in Earth Sciences National Scientific and Technical Research Council Geological Survey of Brazil Center for Technological Development Department of Geology University of Tartu Department of Geology São Paulo State University Department of Geology São Paulo State University

Research on coastal Brazilian Quaternary eolian systems has significantly progressed in recent years. However, few contributions have been published on eolian depositional forms in Brazilian inland areas. Directly associated with the São Francisco River, the Xique-Xique eolian system is the largest quaternary interior dune field in Brazil (8,000 km²). Despite dune reactivation in some sites during the last decades, most Xique-Xique dunes are stabilized. In this study, we characterize dune morphology, vertical stratigraphic sections and sedimentary facies coupled to a dataset of optically stimulated luminescence (OSL). Four geomorphological zones were recognized and mapped: 1 - simple megadunes; 2 - compound dunes; 3 - perched dunes; and 4 - eolian plains. Simple megadunes (SM) occur as well-preserved parabolic dunes with simple elongated or lobate morphologies, and subordinately, nested, digitate, and superimposed dunes also occur. The SM can be recognized on both sides of the São Francisco River, have length of the arms (L) from 1.2 to 16.3 km, the width (W, distance along the transverse line that joins the two most distant points) from 0.9 to 5.7 km, and heights of up to 30 m at their noses. Six sediment samples have been dated by OSL, revealing ages from 26.5±4.4 ka to 4.8±0.9 ka. Compound dunes (CD) consist of well-preserved parabolic landforms comprising morphologies usually en-echelon and nested. They have L of 0.3-2.0 km and W of 0.3-1.4 km, with a predominant L/W ratio

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

Made available in DSpace on 2022-04-28T19:49:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-03-15 National Research Foundation Aberystwyth University Information on past dryland environments is commonly derived from geomorphological landforms and sediments (‘geoproxies’). The Okavango Delta in the middle Kalahari, Botswana, has been subject to a long history of arid–humid transitions but its potentially rich archive of fluvial geoproxies is largely untapped. Previous palaeoenvironmental studies in the Delta region have focused mainly on aeolian dunes, lacustrine beach ridges, and rare pollen sequences in surrounding locations, and the Delta's channel dynamics have remained poorly constrained, both chronologically and in quantitative palaeohydrological terms. Focusing on the Delta's Xugana region, we present the first optically stimulated luminescence ages for palaeochannel fills and scroll bars, revealing significantly enhanced fluvial activity in the ~7–4 ka interval. Along 120–150 m-wide, sand-bed, sinuous palaeochannels, lateral migration and bend cutoffs were driven by palaeodischarges up to ~350–450 m3 s−1, at least nine times those of the present-day channels. These palaeochannels represent the last major phase of meander activity in the middle and lower Delta. The palaeodischarges imply significantly higher rainfall over the catchment in the mid Holocene, possibly resulting from a southwards shift of the African tropical rainbelt. Over the last few thousand years, diminished fluvial activity in the Xugana region has continued

Made available in DSpace on 2022-04-28T19:41:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Unlike other South American basins, the boundary between Ordovician and Silurian in the Paraná Basin, Brazil, has yet to be studied in detail. This article reports the occurrence and taphonomic analysis of a fauna composed of the organophosphatic brachiopods Kosoidea australis and ?Palaeoglossa sp., the mollusks ?Paleoneilo sp. and ?Cuneamya sp., besides rynchonelliform brachiopods and the ostracods Harpabollia sp. and Satiellina paranaensis. This assemblage indicates a Hirnantian age for the top of the Iapó and the base of the Vila Maria formations, northeastern border of the Paraná Basin. Taphonomic signatures and facies associations point to a pro-glacial environment, at the transitional shoreface, represented by the last sedimentary facies of the Iapó Formation. The overlying transgressive strata represent the beginning of the Vila Maria Formation, in which fossils and lithofacies indicate predominant post-glacial conditions in an offshore setting. Two taphofacies were delineated. One features size- and type-selected fossils, deposited in rain-out facies originated from the melting glacier. The second, with autochthonous to parautochthonous fossils, represents a post-glacial offshore setting. The low faunal diversity points to marine connections between North and South African basins, and with South American basins. Geosciences Institute UNICAMP, Campinas Geosciences Institute University of Brasilia Center for Technological Innovation-CEDES Setor Bancário Norte Department of Geology São Paulo State University Unesp Department of Geology São Paulo State University Unesp FAPESP: 2017/10956-5 CNPq: 459776/2014-2

Made available in DSpace on 2019-10-06T15:47:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-10-01 Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul Geological Society of America National Science Foundation Universidade Estadual Paulista Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) National Geographic Society Empresa Brasileira de Pesquisa Agropecuária Tropical fluvio-lacustrine depositional processes along the toe of the Paraguay fluvial megafan were investigated with a focus on Lake Uberaba (LU), the largest lake in the Pantanal wetlands. A limnogeological analysis of LU was conducted using remote sensing imagery, lake water chemistry, sedimentological and radiochemical data from lake floor samples and short cores. Echo-sounding revealed that LU is deepest (Zmax = ~3.5 m) near its southern shoreline and outlet; the lake is hydrologically open throughout the year and is characterized by a dilute Ca+2-Na+-HCO3 − chemistry. Key environmental controls on sedimentation in LU include inflowing transverse and axial rivers and water level changes, which influence the composition, mixing, accumulation, and the organization of facies. Structureless brown sandy silts with relatively low organic carbon (TOCmean = ~1.7 wt%) and low to moderate biogenic silica (BiSimean = ~1.9 wt%) comprise most offshore lake floor sediments, whereas northern lake margin sediments consist of peaty silts and sandy silts whose origins are linked to inflowing Paraguay megafan distributary channels. Sediment core stratigraphy revealed that extant lacustrine deposits are underlain by oxidized clayey silts and sands, suggesting recent subaerial exposure of the basin floor. Sedimentary datasets conclusively suggest that LU is a shallow overfilled lake basin that is strongly influenced as a depositional system by its persistently open hydrology, shoreline channel density, and absence of margin coincident topography. This study provides new insights on lacustrine landform development in distal megafan settings, which is important for improving our understanding of fluvial landscapes. Department of Earth and Environmental Sciences University of Kentucky Universidade Federal de Mato Grosso do Sul - Câmpus do Pantanal Embrapa Pantanal Universidade Estadual de Maringá - UEM Programa de Pós-Graduação em Ecologia de Ambientes Aquáticos Continentais Universidade Estadual Paulista - Unesp Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista - Unesp Instituto de Geociências e Ciências Exatas Fundação de Apoio ao Desenvolvimento do Ensino, Ciência e Tecnologia do Estado de Mato Grosso do Sul: 083/2016 National Science Foundation: 1541247 Universidade Estadual Paulista: 2014/06889-2 CNPq: 447402/2014-5 CNPq: 448923/2014-9 National Geographic Society: 9797-15 Empresa Brasileira de Pesquisa Agropecuária: SEG 03.17.00.047.00.00

Made available in DSpace on 2019-10-06T16:42:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-01-01 Many fossil brachiopod genera are used to comprehend previous geological settings. Such fossils often provide trustworthy information about ancient earth configurations, such as the supercontinent Gondwana. This study presents a new occurrence of a discinoid brachiopod, from the Iapó and Vila Maria Formations of the Paraná Basin. Fossiliferous strata overlie deposits of glacial and post-glacial times, here interpreted as Hirnantian in age. This is the first occurrence of Kosoidea for Paleozoic strata of Brazilian Sedimentary Basins. A new discinoid species Kosoidea australis sp. nov. is erected. Disarticulated valves are extremely abundant as juveniles in transgressive marine mudrocks. The new species is characterised by a convexo-plane shell and a marked posterior triangular pedicle opening. The microornamentation consists of pits arranged in radial rays, mostly visible on the dorsal valve surface. Adults are rare, and a size-sorting process probably sieved and fragmented the valves during transportation and fossilisation. Medium to large discinoids–such as the one here described–are commonly associated with chilly waters. The presence of this genus both in Soom Shale (Cape Basin, South Africa) and in Paraná Basin, associated to sedimentological data points to a possible connection between the two in marginal basins of Gondwana, during the Early Paleozoic. urn:lsid:zoobank.org:pub:0E35F946-051C-4DD7-AA43-23E0FFD59FF3. Department of Geology and Natural Resources Institute of Geosciences State University of Campinas Laboratory of Paleohydrogeology Institute of Geosciences State University of Campinas Laboratory of Micropaleontology Institute of Geosciences University of Brasília Campus Darcy Ribeiro Applied Geology Department. São Paulo State University - UNESP/IGCE Applied Geology Department. São Paulo State University - UNESP/IGCE

The Aptian Crato Konservat-Lagerstätte is renowned for its exceptionally preserved fossils in lacustrine laminated limestones. Although previous works on this site include numerous taxonomic studies, its taphonomy remains a subject of debate. Herein, we present new data on the taphonomy of decapod crustaceans preserved in wrinkle laminites, highlighting the role of microbial mats in enhancing fossil preservation. Our results suggest that benthic microorganisms may have promoted protection and organic mineralization of some of the allochthonous to parautochthonous organic remains within the microbial laminites of the Crato lake. Overall, this work provides the first empirical evidence that the preservational pathways of the fossils in the Crato Konservat-Lagerstätte involved microbial mats.

Made available in DSpace on 2019-10-04T12:40:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2019-07-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Petrobras Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) The Aptian Romualdo Formation is a siliciclastic-dominated sedimentary unit recording the last marine ingression within the Cretaceous interior basins of northeastern Brazil. At the western margin of the Araripe Basin, rocks of the Romualdo Formation are mainly represented by carbonates resting abruptly over the Proterozoic crystalline basement. Detailed mapping and stratigraphic analysis revealed two stromatolite fields that were described and discussed for the first time. Several bioherms, biostromes and isolated stromatolites characterized by distinct microbialite morphologies associated with echinoid-rich strata have been identified, suggesting that hypersalinity, water depth and hydraulic conditions were the main factors controlling stromatolite morphogenesis. A cm-thick amalgamated bivalve rudstone, resting directly on the basement and representing a shell concentration formed above the fair-weather wave base was also recorded. Based on the regional distribution of the stromatolite types and associated sedimentary fades, we interpret the depositional environment as a local low gradient carbonate ramp deepening to the east. Our data robustly indicated that the western rocky shorelines of the Araripe Basin during the Aptian were populated by microbial mats and stromatolites in a condition analogous to the modern world-famous Hamelin Pool, Shark Bay, Western Australia. Finally, the development of stromatolites and echinoid-bearing microbialites at the western margin of the basin may be correlated with the formation of bakevelliid- and cassiopid-rich shell beds in the upper part of the Romualdo Formation at the eastern margin. (C) 2019 Elsevier B.V. All rights reserved. Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Dept Geol Aplicada, Ave 24A,1515, BR-12506900 Rio Claro, Brazil Friedrich Alexander Univ Erlangen Nurnberg, FG Palaoumwelt, GeoZentrum Nordbayern, Loewenichstr 28, D-91054 Erlangen, Germany Univ Estadual Paulista, Inst Biociencias, Dept Zool, BR-18618000 Botucatu, SP, Brazil Univ Reg Cariri, Dept Ciencias Biol, Campus Pimenta 1161, BR-63100000 Crato, Brazil Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Dept Geol Aplicada, Ave 24A,1515, BR-12506900 Rio Claro, Brazil Univ Estadual Paulista, Inst Biociencias, Dept Zool, BR-18618000 Botucatu, SP, Brazil FAPESP: 2016/13214-7 FAPESP: 2017/20803-1 FAPESP: 18/01750-7 Petrobras: 2014/00519-9 CNPq: 444070/2013-1 CNPq: 401039/2013-5 CNPq: 1082 30017/2015-3 CNPq: 152385/2016-9 CNPq: 301294/2018-6

Made available in DSpace on 2021-06-25T10:32:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-08-01 Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) National Research Council The tectonic evolution of the Equatorial Atlantic Gateway (EAG) throughout the early Cretaceous had global implications. This break-up of western Gondwana has played a significant role in causing, or amplifying, environmental changes due to its influence on ocean chemistry, nutrient distribution, water mass circulation, and bottom waters ventilation. However, the timing of its establishment and the areal extent of this oceanic gateway is still poorly constrained. Marine settings were recorded by the black shales of the Romualdo Formation (Late Aptian), Araripe Basin - Northeastern Brazil, which are known worldwide for their fossil content and importance for paleogeographic reconstructions of Gondwana. In this contribution, we present multiproxy analyses, combining macro- and micropaleontological, as well as sediment compositional data to evaluate paleoenvironmental conditions during the deposition of sedimentary strata assigned to the Romualdo Formation. We investigate the ~100-m-thick succession of the Sobradinho Section, which is the most complete exposure of the Romualdo Formation. Increased abundances of ostracods, the occurrence of agglutinated benthic foraminifera, bakevelliid bivalves, and cassiopid gastropods coincide with levels of relatively high paleosalinity estimates based on the Sr/Ba (strontium/barium) and S/TOC (sulfur/total organic carbon) ratios. These levels correspond to a transgressive system tract and the lower interval of a highstand systems tract. Throughout the section, black shales occur intercalated with sparse sandstone and calcarenite levels, and the deposition of these black shales is associated with dysoxic to anoxic bottom water conditions, as suggested by the V/Cr (vanadium/chrome) ratio. The occurrence of stagnant bottom water conditions may explain the mass mortality of ostracods in the lower interval of the succession. The upper part of the highstand system tract in the studied section was deposited in coastal environments and is characterized by coarser-grained siliciclastic-dominated facies (high log(Zr/Rb) (zirconium/rubidium) ratio), as well as increased phytoclasts and terrigenous (high magnetic susceptibility) contents. Instituto Tecnológico de Micropaleontologia (itt Fossil) Universidade do Vale do Rio dos Sinos, Av. UNISINOS, 950 Departamento Interdisciplinar - Centro de Estudos Costeiros Limnológicos e Marinhos Universidade Federal do Rio Grande do Sul, Avenida Tramandaí 976 Departamento de Geologia Instituto de Geociências Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves, 9500 Petrobras Cenpes BPA Cidade Universitária, Ilha do Fundão Instituto de Biociências Universidade Estadual Paulista - Unesp Departamento de Geologia Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista - Unesp, Avenida 24A, 1515 Instituto de Biociências Universidade Estadual Paulista - Unesp Departamento de Geologia Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista - Unesp, Avenida 24A, 1515 Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul: #16/2551-0000213-4 CNPq: #201508/2009- 5 CNPq: #304022/2018-7 CNPq: #427280/2018-4 FAPESP: 2004/15786-0 FAPESP: 2014/27337-8 National Research Council: 401039/2014-5

Made available in DSpace on 2021-06-25T12:40:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-15 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Petrobras The Aptian evaporitic transitional sequence (sag phase) of the Brazilian marginal basins records the first connection between the Central and South Atlantic oceans in the equatorial area. During this phase, lacustrine carbonate reservoirs and giant salt deposits developed in the southern basins of Santos and Campos, forming world-class petroleum reservoirs. The sag succession is also well-preserved in the interior rift basins of north-eastern Brazil, where upper Aptian strata are represented by a continuous section. This contribution presents an interpretation of the evolution of a third-order depositional sequence comprising lacustrine limestones, marine siliciclastic facies and evaporite deposits of the intracontinental Araripe Basin. The Lowstand Systems Tract is characterized by fluvial deposits filling accommodation generated during the syn-rift phase. The overlying deposits comprise marine facies with preservation of dinoflagellates and marine ichnotaxa, evidencing marine deposition in bayhead delta settings. The transgressive surface is represented by limestones, including the Konservat-Lagerstatte laminites, onlapping the basement rocks. Above, tide-dominated bay deposits with distinct subtidal, intertidal and supratidal portions are recorded. The Maximum Flooding Surface is a dark shale below foreshore to shoreface facies, marking the beginning of the Highstand Systems Tract, culminating with deposition of evaporites (gypsum and anhydrite). The stratigraphic architecture and palaeocurrents measured in different facies associations suggest that marine waters reached the basin from the south. The data unequivocally records late Aptian marine ingressions of an incipient South Atlantic Ocean over the interior basins of north-eastern Brazil, while lacustrine conditions were still prevailing in the Pre-Salt sag units of the Santos and Campos basins. Univ Fed Parana, Inst LAMIR, Dept Geol, Av Cel Francisco H Santos 100, BR-81531980 Curitiba, PR, Brazil Univ Fed Ouro Preto, Escola Minas, Dept Geol, BR-35400000 Ouro Preto, MG, Brazil Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Dept Geol, Ave 24-A,Bela Vista 178, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Distrito Rubiao Jr S-N 510, BR-18618970 Botucatu, SP, Brazil Univ Saskatchewan, Dept Geol Sci, Saskatoon, SK S7N 5E2, Canada Univ Estadual Paulista, Inst Geociencias & Ciencias Exatas, Dept Geol, Ave 24-A,Bela Vista 178, BR-13506900 Rio Claro, SP, Brazil Univ Estadual Paulista, Inst Biociencias, Distrito Rubiao Jr S-N 510, BR-18618970 Botucatu, SP, Brazil FAPESP: 2016/13214-7 CNPq: 401039/2014-5 Petrobras: 2014/00519-9

Climate, tectonic and sea level factors contribute to the geomorphic evolution of large rivers. Rivers draining settings where the tectonic activity and sea level influence are minors allow clearer signals from climate variation to be identified. Thus, rivers that run exclusively in tectonically quiescent areas and away from coastal regions are the most suitable targets to understand the climate drivers. In northeastern Brazil, the São Francisco River is one of the largest cratonic rivers in South America, with an extension of 2,900 km, and its thousand years evolution is registered by Quaternary deposits preserved as terraces. With the upper course in semi-humid settings, the São Franciscos flows northward, but with a watershed mostly under semi-arid conditions. Hence, the São Francisco River’s deposits are an excellent fluvial sedimentary record to shed light on how large tropical rivers responded to climatic changes of the Quaternary. We studied a 200 km stretch of the middle course of the São Francisco in the State of Bahia by using remote sensing methods and field surveys for geomorphological and sedimentological analyses combined with optically stimulated luminescence dating (OSL). We recognized at least four phases of fluvial aggradation (>90 ka; 65 to 39 ka; 18 to 9.5 ka and 380 years to recent) and three phases of incision (I1 - 85 to 65 ka; I2 - 39 to 18 ka and I3 - 9.5 to 1.0 ka). Two aggradation events and the incision event I2 are also observed in the upper course of the São Francisco River. The river incision events agree with precession insolation cycles (~25 ka) at latitude 10° S, which influence the rainfall in the area. The incision events occurred probably due to increased fluvial discharge produced by intensification of the South Atlantic Convergence Zone (SACZ), which has great influence on precipitation over the upper São Francisco river. Thus, we conclude that the aggradation-incision cycles of the São Francisco River during the last 100 ka are likely products of millennial precipitation variation, possibly related to precession cycles. The events of high sedimentation rate in the São Francisco river mouth are partially correlated with incision phases in its middle course. This suggests that sedimentation in plains of large plateau rivers can be decoupled from the coastal area.Keywords: Late Quaternary, fluvial response, OSL dating, aggradation-incision cycles, precession cycles

The Paraná River has being extensively studied in terms of its hydrological and sedimentological aspects, but the geological history of its fluvial plain is still poorly understood due to the lack of geochronological data. Most of the published studies are focused on the low and middle reaches, and the region upstream of the Porto Primavera dam is an area almost unknown in terms of geomorphic evolution. Here, we aim to investigate the succession of geological events responsible for the evolution and current configuration of the Upper Paraná River fluvial system, in the stretch between the Jupiá and Porto Primavera Hydroelectric Plants (São Paulo and Mato Grosso states). Thus, we used an integrated approach including remote sensing data, geomorphology, sedimentology, bathymetric profiles, and chronological methods. Four geomorphological compartments were identified and three of these compartments were dated by Optically Stimulated Luminescence (OSL): Unit 1, raised terrace with circular and semicircular ponds (~150 ka); Unit 2, intermediate terrace with small ponds and waterlogged areas (~60 ka); Unit 3, low terrace with preserved paleochannels (~39–35 ka); and Unit 4, current river plain (>9 ka). The geomorphological units were correlated with previous studies downstream of the studied area and their sedimentary characteristics and depositional ages suggest that their genesis is linked to changes in climatic and hydrological conditions during the Late Quaternary. Units 1, 3, and 4 are considered extensions of the geomorphological units Taquaruçu, Fazenda Boa Vista, and Rio Paraná, respectively. Unit 2 is a compartment with unique morphological characteristics, therefore not correlated with units presented in previous works. Further, two main knickpoints were identified, suggesting an important control in the sedimentation and development of the terrace levels. Thus, this work brings new data on the evolutionary history of the Paraná River, which allows us to understand that the development of the terrace levels and the floodplain of the upper reaches are strongly controlled by the climatic changes that occurred during the Late Quaternary.

Made available in DSpace on 2021-06-25T10:15:41Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Petrobras Tunnel valleys are subglacial incisions formed mainly by meltwater erosion on soft sediment overridden by glaciers. Despite being common in the Pleistocene and Ordovician glacial record, where their fills constitute excellent aquifers and hydrocarbon traps, tunnel valleys are poorly recognized in late Paleozoic strata. Other types of glacial and non-glacial valleys, on the other hand, have been widely reported from Carboniferous and Permian glacial successions, most cut into the basement or older sedimentary rocks and interpreted as glacial valleys eroded by outlet glaciers draining high-relief settings. The degree of glacial influence on the formation of these valleys has strong implications for the volume of ice during late Paleozoic glaciations. In this paper, we report the Lapa sandstone, an exhumed valley-fill succession encased in Pennsylvanian glacial rocks of eastern Paraná Basin, southern Brazil, and its subsurface counterparts. The Lapa sandstone forms a slightly sinuous ribbon several tens of kilometers long, 1500 m wide and 100 m thick composed essentially of glaciofluvial facies. By comparing the external geometry and the sediment fill of the valley with several types of erosive-based, elongated sediment bodies, we conclude that the Lapa formed as the infilling of a tunnel valley cut beneath an ice margin that advanced to the north onto poorly consolidated, mud-rich sediments. Valley fills previously mapped in the subsurface area to the west are considered to have been formed by the same mechanism and during the same glaciation event. The Lapa tunnel valley and its subsurface counterparts are the first example reported from the late Paleozoic glacial record in South America, but similar features are also expected in any formerly glaciated basin, and their recognition may help in estimating the extent of glaciation across the region and guiding exploration for hydrocarbon traps. Departamento de Geologia UFPR - Universidade Federal do Paraná, Caixa Postal 19001 Departamento de Geologia UNESP - Universidade Estadual Paulista, Av. 24-A, 1515 Programa de Pós-Graduação em Geologia UFPR - Universidade Federal do Paraná, Caixa Postal 19001 Programa de Pós-Graduação em Geologia UNISINOS - Universidade do Vale do Rio dos Sinos, Av. Unisinos, 950 Brazil Petroleum Studies, Av. Atlântica 1130 Departamento de Geologia UNESP - Universidade Estadual Paulista, Av. 24-A, 1515 CNPq: 461650/2014–2 Petrobras: BG-01 Petrobras: BG29 CNPq: PQ 302842/2017-9 CNPq: PQ 304925/2017-9 CNPq: PQ 311175/2019-8

Made available in DSpace on 2022-04-28T19:50:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Empresa Brasileira de Pesquisa Agropecuária Fundação de Apoio à Pesquisa, Universidade Federal de Goiás The Pantanal wetland is a mosaic of landscapes that brings together rich biodiversity with the valuable activities of fishing, tourism and ranching. Human occupation and land use in the headwaters have intensified the rate of channel avulsions in the lower reaches of the largest megafan on the Taquari River. This study evaluates the long-term changes of landscapes in the active depositional lobe of the Taquari megafan from the perspective of local communities of pantaneiros. Maps derived from multiple decades of multispectral Landsat data have proven useful for studying land cover changes through the relationship between dry (terrestrial vegetation and soil/dry pastures) and humid landscapes (open waters, aquatic macrophytes and wet soils), as well as through Sankey diagrams and spatiotemporal mapping with Boolean operations according to the rate of dryland recovery. We found that dryland recovery associated with an older and smaller avulsion (known as Zé da Costa) is analogous to that of a most recent and much larger avulsion (known as Caronal), which is still ongoing and has greater importance due to the scale of the impacts. Land value and fish capture depreciate as the partial Caronal avulsion still evolves, increasing the likelihood of environmental conflicts. While pantaneiros no longer profit from ecosystem services of provision (e.g., livestock or fishing), dryland recovery may deliver quantifiable ecosystem services of regulation. The strengthening of partnerships among stakeholders and the implementation of environmental compensation mechanisms are central for the best management of the Pantanal's megafans that ensure quality of life for all pantaneiros. Programa de Pós-Graduação em Recursos Naturais Universidade Federal de Mato Grosso do Sul, MS Embrapa Pantanal, MS Instituto de Biociências Universidade Federal de Mato Grosso do Sul, MS Department of Earth and Environmental Sciences University of Kentucky Campus do Pantanal Universidade Federal de Mato Grosso do Sul, MS Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista, SP Embrapa Informática Agropecuária, SP Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista, SP Empresa Brasileira de Pesquisa Agropecuária: 03.17.00.047 Fundação de Apoio à Pesquisa, Universidade Federal de Goiás: 2014/06889-2

Made available in DSpace on 2021-06-25T10:57:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Although virtual outcrops or digital outcrop model applications in geological studies are becoming increasingly common, virtually no attention has been given to acquisition of palaeocurrent data from cross-strata. Palaeocurrent indicators are abundant in the sedimentary record, mainly as cross-strata, and present compelling implications for basin analysis, plate tectonics and palaeoenvironmental reconstructions, as well as for sediment transport systems. Palaeocurrents from cross-strata also comprise a quantifiable parameter in sedimentary successions that can be used in quantitative modelling of depositional architecture with implications for reservoir characterization through outcrop analogue studies. A common obstacle in obtaining large cross-strata orientation datasets is the limited access to steep and high outcrop faces, as well as financial and time restrictions on field work. To overcome these issues, the simplest workflow for drone-based acquisition, photogrammetric processing and analysis of virtual outcrops aiming at the attainment of palaeocurrent data from cross-strata is appraised here. The results show that orientations of cross-beds measured on virtual outcrops, with and without ground control points, and using two different levels of resolution downsampling, are comparable to field measurements using analogue and electronic devices. Time and financial resources can thus be saved by using the straightforward method presented here to supplement palaeocurrent mapping across wide areas and distinct stratigraphic intervals. Geology Lab School of Technology University of Campinas, Rua Paschoal Marmo, 1888, Jardim Nova Itália Institute of Geosciences University of São Paulo, Rua do Lago, 562, Cidade Universitária Institute of Marine Science São Paulo Federal University, Rua Carvalho de Mendonça, 144, Encruzilhada Departamento de Geologia (DGEOL) / Programa de Pós-graduação em Geociências e Análise de Bacias Universidade Federal de Sergipe, Marechal Rondon Ave., Geology Bldg., Multi-user Complex, Rosa Elze Departamento de Geologia Aplicada Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista/UNESP, Avenida 24-A, Bela Vista, 178 Departamento de Geologia Aplicada Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista/UNESP, Avenida 24-A, Bela Vista, 178

Made available in DSpace on 2021-06-25T10:27:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Several sag-type basins apparently developed from rift systems, but there is no consensus about how and if these grabens influenced the sedimentation of the post-rift thermal subsidence phase. The Ediacaran Jaibaras Rift Basin is one of the best-exposed sedimentary records among the NE Brazil late Precambrian - early Cambrian rift system, cropping out at the eastern margin of the intracratonic Parnaíba Basin and extending below it towards the west. Here we present detrital zircon U-Pb ages of rocks from the Jaibaras (Aprazível Formation) and Parnaíba (Ipu Formation) basins, in order to understand the provenance patterns, maximum depositional ages (MDA) and age relationship between these units. The MDA for the Aprazível Formation (c. 499 ± 5 Ma) indicates a Cambrian age for the upper part of the Jaibaras Basin. The bulk U-Pb data indicate that the Ipu Formation started to deposit during late Cambrian and/or Early Ordovician time, despite its MDA (c. 528 ± 11 Ma) being older than that of the Aprazível Formation. Detrital zircon provenance suggests that the primary source areas for the early deposits of the Parnaíba Basin were mountains related to the Brasiliano Orogeny to the south and SE (e.g. Rio Preto and Riacho do Pontal metamorphic belts). Finally, our data emphasize the key change in source areas from the rift to the initial deposition of the intracratonic phase, indicating major depositional style changes between both basins after the Gondwana assembly. Departamento de Geologia Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista - Unesp, Avenida 24-A, Bela Vista, 178 Departamento de Geologia Universidade Federal de Ouro Preto Campus Morro Do Cruzeiro S/n Instituto de Engenharia Ciência e Tecnologia Universidade Federal Dos Vales Do Jequitinhonha e Mucuri (UFVJM) Departamento de Geologia Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista - Unesp, Avenida 24-A, Bela Vista, 178

Made available in DSpace on 2021-07-14T10:54:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-21. Added 1 bitstream(s) on 2021-07-14T11:41:10Z : No. of bitstreams: 1 S2317-48892021000100303.pdf: 9877652 bytes, checksum: 8f99643b443c0258fa2d0b3ec0b4c75e (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Petrobras The Aptian Crato Formation is world renowned for its well-preserved fossils in microbially-induced laminated limestones, which are regarded as one of the main Cretaceous Konservat-Lagerstätte of the geological record. Detailed stratigraphic investigation and mapping of the up to 90-m-thick Crato Formation at the eastern border of the Araripe Plateau allowed recognition of a regionally persistent fossil-bearing muddy interval, herein defined as the Caldas Bed. At its type locality, it is defined as an up to 2-m-thick coarsening-upward succession of grey/green mudstone and interbedded sandy siltstone and claystone. The 0.85- to 2-m-thick interval was recognized in several localities along the outcrop belt, and it is bounded by sharp, lower (Konservat-Lagerstätte limestone) and upper (sandstone and heterolithic facies) contacts. Despite previous literature data suggesting the presence of marine mollusks, the bed contains freshwater bivalves, small gastropods, spinicaudatans, plant remains, trace fossils, and rare ostracods. The Caldas Bed records benthic paleocommunities representing a short-term isochronous regional freshening event, marked by abrupt changes in sedimentation pattern, bathymetry, salinity, oxygenation and water chemistry. Universidade Federal do Paraná, Departamento de Geologia Universidade Estadual Paulista “Júlio de Mesquita Filho”, Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista “Júlio de Mesquita Filho”, Instituto de Biociências Friedrich-Alexander-Universität Erlangen-Nürnberg, FG Paläoumwelt Universidade Estadual Paulista “Júlio de Mesquita Filho”, Instituto de Geociências e Ciências Exatas Universidade Estadual Paulista “Júlio de Mesquita Filho”, Instituto de Biociências FAPESP: 2016/13214-7; 2017/22036-8; 2017/20803-1; 2018/01750-7 CNPq: 401039/2014-5 Petrobras: 2014/00519-9

Made available in DSpace on 2021-06-25T10:14:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Universidade Estadual Paulista Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Composite islands that originate from central bars are one of the most frequent types of islands in the Paraná River and in many large rivers in the world. The aim of this study is to highlight island-forming processes and the evolution of an island on a large anabranching tropical river over a period of 101–104 yr. Mutum Island in the Upper Paraná River, Brazil (mean discharge = 9000 m3 s−1), was chosen because of its large size (>15 km in length) and by the formative processes that have been active over the last 8 ka. Our analysis used a 60-yr series of satellite images and aerial photos, and 16 absolute dates (14C and OSL) from 11 vibro-cores and outcrops. Mutum Island was formed by the stabilization, vertical aggradation, and vegetal development of a central bar. Island expansion occurred through the addition of lateral and frontal bars. Island deposits exhibit three main lithosomes: coarse to fine basal sand deposits more than 3 m below the island surface related to channel processes; middle sandy mud layers 2–4 m thick formed by annexation processes; and upper massive mud formed by flood flow deceleration over the island. The age of deposits decreased from the center (8200 BP) to the banks (present day) of the island. The predominantly lateral expansion of island deposits resulted in a different depositional architecture to that described for other anabranching rivers. This study demonstrates that the formation and evolution of Mutum Island has been relatively stable since the beginning of the Holocene. The model presented for the Mutum Island represents a useful contribution on the understanding of large anabranching river systems. Graduate Program in Geography Western State of Paraná UNIOESTE/Marechal Cândido Rondon Institute of Geosciences São Paulo State University UNESP Graduate Program in Freshwater Ecology State University of Maringá UEM/Maringá Graduate Program in Geography Federal University of Mato Grosso do Sul UFMS/CPTL Institute of Geosciences São Paulo State University UNESP CNPq: 304925/2017-9 CNPq: 308846/2010-9 CNPq: 405190/2018-2 CNPq: 474245/2011-01

Despite the absence of metazoans, structures resembling animal traces are common in a soda lake from the western Brazil Pantanal wetland. Pantanal soda lakes are ecologically extreme environments that preclude complex life, allowing extremophiles to flourish. Direct observation indicates that these structures are pseudotraces, representing groove marks that result from the interaction of wave-transported floating rafts of epibenthic microbial mat fragments with the substrate. Variations in wind/wave direction and intensity result in marks of different size and morphology. The most common pseudotraces are simple and slightly curved, narrow grooves (type 1), whereas others are straight and present raised lateral ridges (type 2). Both are V-shaped in cross section. Type 3 comprises long, sinuous, shallow grooves, displaying internal crescentic laminated infill and U-shaped cross section. The similarity of these pseudotraces to Ediacaran structures usually interpreted as animal trace fossils suggests that care should be exercised in their analysis. A set of criteria is proposed to differentiate microbially induced pseudotraces from trace fossils. Analysis of Ediacaran structures needs to be performed on a case-by-case basis, taking into account morphology, orientation, and preservation style of the structure, sedimentary environment, and presence or absence of microbial mats., Centro de Investigaciones Geológicas

Made available in DSpace on 2020-12-12T01:17:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Ministério da Educação Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Anabranching patterns are characteristic of the largest rivers in the world. We have chosen to study the Paraná River because of its worldwide importance among the great rivers and the large database available from over four decades of research. In this paper, we present results on the classification, origin, evolutionary processes, and sedimentary records of islands that form anabranching patterns in the Upper Paraná River in Brazil. These islands are formed by in-channel processes that drive their evolution from central bar islands and by off-channel processes that form floodplain-excised island. Both types of islands can increase in area by the annexation of lateral bars, forming composite islands. The islands formed by floodplain excision are normally larger than the other types, with ages of up to 14.6 ka. The sedimentary records of these islands are relatively simple. Central bar islands present a lower lithosome comprising sandy channel deposits (Sp, St, Sm, and Sm(o) facies) that correspond to central and lateral bar formation, followed by a mud sequence (Fm, Fl, and Fm(o) facies) deposited by vertical accretion events during flood stages. Floodplain-excised islands have the same sedimentary sequence as the floodplain from which they were detached. The in-channel island-forming processes described in this paper may have been operating since the beginning of the Holocene. The understanding of island origin and evolution processes presented in this paper is fundamental to ecological and geomorphological studies, as in the sustainable management of large anabranching rivers. Graduate Program in Geography Western State of Paraná UNIOESTE/Marechal Cândido Rondon Institute of Geosciences and Exact Sciences São Paulo State University UNESP Graduate Program in Freshwater Ecology State University of Maringá UEM/Maringá Graduate Program in Geography Federal University of Mato Grosso do Sul UFMS/CPTL Institute of Geosciences and Exact Sciences São Paulo State University UNESP CNPq: 30492/2017-9 CNPq: 308846/2010-9 CNPq: 405190/2018-2 CNPq: 474245/2011-01