Depositional architecture and dynamics of semi-arid fluvial systems : the Bauru Group in the Triângulo Mineiro region (Upper Cretaceous)

Orientadores: Giorgio Basilici, Thiago da Silva MarinhoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de GeociênciasResumo: Modelos de fácies empregados no entendimento de depósitos fluviais são atualmente construídos sobre uma perspectiva uniformitarista. Através desta perspectiva, rios tributários modernos, localizados em bacias sedimentares de baixo potencial de preservação, predominantemente de regiões úmidas, são utilizados como análogos para a compreensão de antigos sistemas fluviais. Tal abordagem estabelece um arcabouço empírico-teórico deficitário para o entendimento de antigos sistemas fluviais áridos e semi-áridos, negligenciando a elevada complexidade e variabilidade espaço-temporal associadas a estes sistemas, por consequência fornecendo modelos pouco precisos na organização do arranjo estratigráfico resultante. Pesquisas recentes realizadas em mais de 700 bacias sedimentares continentais modernas demonstram que a totalidade das bacias analisadas, endorréicas ou exorréicas, são compostas predominantemente por sistemas aluviais e fluviais distributários. Dessa maneira, a atual aplicação de modelos deposicionais uniformitarísticos, baseada principalmente em sistemas fluviais tributários e em bacias não-agradacionais, limita o entendimento de arquitetura de fácies no registro geológico. A margem nordeste da Bacia Bauru abriga depósitos fluviais desenvolvidos sobre contexto climático árido a semi-árido durante o Cretáceo Superior (Grupo Bauru). Estes depósitos oferecem as condições ideais para o desenvolvimento de sistemas fluviais distributários. Desta forma, este trabalho aplica o modelo de sistema fluvial distributário para explicar a organização estratigráfica e reconstruir o ambiente deposicional destes depósitos fluviais, priorizando os fatores controladores na dinâmica temporal e espacial de alta frequência observados nestes depósitosAbstract: Fluvial deposits are currently studied through a uniformitaristic facies model approach. This perspective considers modern tributaries, located in non-aggrading, humid settings as analogues for understanding ancient fluvial systems. The method stablishes insufficient empirical and theoretical background to the study of dryland (arid and semi-arid) fluvial systems, neglecting their highly complex spatio-temporal variability, consequently offering innacurate models for their stratigraphic framework. Current studies conducted on more than seven hundred modern continental sedimentary basins demonstrated that the totality of the analysed basins, endohreic or exohreic, are composed predominantly by alluvial and fluvial distributary systems. Consequently, current application of uniformitaristic depositional models, based primarily on tributary, non-aggrading basins, restricts the comprehension of facies architecture of fluvial succession in the geologic record. The northeastern margin of the Bauru Basin hosts fluvial deposits developed under dryland settings during the Upper Cretaceous (Bauru Group). The setting under which the deposits were formed offer ideal conditions to the development of distributary fluvial systems. Therefore, this work applies the distributary fluvial system model to explain the stratigraphic organization and reconstruct the depositional environment of the fluvial deposits, prioritizing the controlling factors on the high-frequency temporal and spatial dynamics observed in the ancient systemMestradoGeologia e Recursos NaturaisMestre em Geociências2016/06968-5;132001/2016-0FAPESPCNP

First titanosaur dinosaur nesting site from the Late Cretaceous of Brazil

Titanosaurs were successful herbivorous dinosaurs widely distributed in all continents during the Cretaceous, with the major diversity in South America. The success of titanosaurs was probably due to several physiological and ecological factors, in addition to a series of morphological traits they achieved during their evolutionary history. However, the generalist nesting behaviour using different palaeoenvironments and strategies was key to accomplish that success. Titanosaur nesting sites have been found extensively around the world, with notable records in Spain, France, Romania, India, and, especially, Argentina. Here, we describe the first titanosaur nesting site from the Late Cretaceous of Brazil that represents the most boreal nesting site for South America. Several egg-clutches, partially preserved, isolated eggs and many eggshell fragments were discovered in an Inceptisol palaeosol profile of the mining Lafarge Quarry, at the Ponte Alta District (Uberaba Municipality, Minas Gerais State), corresponding to the Serra da Galga Formation (Bauru Group, Bauru Basin). Although classical mechanical preparation and CT scans have not revealed embryonic remains in ovo, the eggs and eggshell features match those eggs containing titanosaurian embryos found worldwide. The morphology of the egg-clutches and observations of the sedimentary characteristics bolster the hypothesis that these sauropods were burrow-nester dinosaurs, as was already suggested for the group based on other nesting sites. The egg-clutches distributed in two levels along the Lafarge outcrops, together with the geopalaeontological data collected, provide clear evidence for the first colonial nesting and breeding area of titanosaur dinosaurs in Brazil.Fil: Fiorelli, Lucas Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Martinelli, Agustín Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina. Universidade Federal do Triângulo Mineiro; BrasilFil: da Silva, João Ismael. Prefeitura Municipal de Uberaba; Brasil. Universidade Federal do Triângulo Mineiro; BrasilFil: Hechenleitner, Esteban Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; Argentina. Universidad Nacional de La Rioja; ArgentinaFil: Soares, Marcus Vinícius Theodoro. Universidade Estadual de Campinas; BrasilFil: Silva Junior, Julian C. G.. Universidade de Sao Paulo; Brasil. Universidade Federal do Triângulo Mineiro; BrasilFil: da Silva, José Carlos. Associação Brasileira dos Criadores de Zebu; BrasilFil: Borges, Élbia Messias Roteli. Escola Estadual Presidente João Pinheiro; BrasilFil: Borges Ribeiro, Luiz Carlos. Universidade Federal do Triângulo Mineiro; Brasil. Associação Brasileira dos Criadores de Zebu; BrasilFil: Marconato, André. Universidade de Sao Paulo; BrasilFil: Basilici, Giorgio. Universidade Estadual de Campinas; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: da Silva Marinho, Thiago. Universidade Federal do Triângulo Mineiro; Brasi

Sistemas fluviais de ambiente árido : análise de fáceis e sequencialidade do ponto 1 do Price (Peirópolis, Bacia Bauru)

t: Located in the Triângulo Mineiro region, the Serra da Galga Member crops out along several acknowledged geosites, vastly mentioned in the literature, among which the "Ponto 1 do Price" is here highlighted as the most representative. In this project, the deposits from the member were studied through facies analysis, facies association, architectural deposition and finally sequence analysis by reconstructing the stratigraphic framework from the member. 10 lithofacies were identified and associated to 7 architectural elements related to channel and floodplain fill deposits. Two fossil samples belonging to both, vertebrate and invertebrate, were identified. The succession was divided into 6 sedimentary sequences, which allowed relating the Serra da Galga member to a braided fluvial system developed under proximal, arid to semi-arid conditions, with an architectural deposition controlled by avulsion and autogenic cycles, responsible for the typical aggradational stacking observed in the sequences Resumo: Na região do Triângulo Mineiro, o membro Serra da Galga aflora ao longo de diversos geossítios consagrados na literatura, dentre os quais se destaca o Ponto 1 do Price como modelo mais representativo. Neste trabalho, os depósitos do membro foram estudados através de análise faciológica, identificação de associações de fácies, arquitetura deposicional e analise sequencial através da reconstrução do arcabouço estratigráfico. Foram identificadas 10 litofácies, por sua vez associadas a 7 elementos arquiteturais de preenchimento de canal e planície de inundação. Dois exemplares fósseis pertencentes a vertebrados e invertebrados foram identificados. A sucessão analisada foi compartimentada em 6 sequências sedimentares, que permitiram associar a sucessão sedimentar do Membro Serra da Galga a depósitos de um sistema fluvial entrelaçado desenvolvido em zona proximal sobre condições áridas a semi-áridas, com arquitetura deposicional controlada processos de avulsão e ciclos autogênicos que conferem o caráter agradacional das sequências identificada

Morphology, accumulation and preservation of draa systems in a precambrian erg (Galho do Miguel Formation, SE Brazil)

Proterozoic aeolian successions tend to exhibit a low complexity in the architectural organisation, generally related to simple dunes with low morphological diversity. Although most palaeoenvironmental reconstructions of ancient ergs confirm this scenario, the general conditions in the Precambrian landmass should have allowed the construction of larger and more complex sedimentary aeolian systems than those recorded in the Phanerozoic successions. To address this paradigm, the present work proposes to discuss the development and morphodynamics of ancient draa-scale bedforms and to understand which controlling factors produced the apparent absence of draa architecture in the Precambrian sedimentary record. For this purpose, this study examines an interval of c. 80 m of the Galho do Miguel Formation, which is a Mesoproterozoic aeolian succession composed of metasandstones showing well-preserved primary sedimentary structures and geometries with excellent vertical and horizontal exposures. A detailed sedimentological analysis allowed the recognition of six main architectural elements: (i) simple transverse dune, (ii) simple linear dune; (iii) compound transverse draa; (iv) complex linear draa, (v) dry interdune and (vi) sand sheet. The lateral and vertical relationships between these architectural elements support the evidence of coeval spatial coexistence of distinct aeolian morphologies (transverse and linear bedforms), probably controlled by lateral variations in sand saturation and in circulation pattern of the palaeowind. The stratigraphic organisation indicates different intervals of draa construction and destruction, which appear to be associated with different sedimentary pulses. The intervals of draa construction represent the vertical succession between simple and compound dunes of similar morphologies, representing temporal variation in sedimentary availability and changes in angle of dune climbing. The erosional and irregular surface at the bottom of compound sets of cross-strata can represent periods of irregular accumulation, associated with partial draa destruction (dune cannibalisation), probably due to seasonal variations in sedimentary availability throughout construction stages. Evidence of a near-surface water table level, as small wave ripples, indicates that the position of the water table was directly linked to the sedimentation pattern throughout these intervals. This relationship implies that ground water was the main controlling factor on sand availability and wind saturation during aeolian morphodynamics, as well as on accumulation and preservation processes. Moreover, in conditions of high rates of subsidence, the thickness accumulated and preserved via water table fluctuation is incorporated in the sedimentary record; otherwise, these deposits would have eroded due to aeolian deflation or fluvial reworking. Apparently, the absence of large and complex aeolian systems in the Precambrian record can be related to the absence of continuous near-surface water table during the draa development, directly decreasing their preservation potential412CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP141812/2015-0; 2018/3062762018-62017/03649-

Sedimentology of a distributive fluvial system: The Serra da Galga Formation, a new lithostratigraphic unit (Upper Cretaceous, Bauru Basin, Brazil)

The Bauru Basin of SE Brazil is a large (ca. 370,000 km2) Upper Cretaceous intracratonic feature, important for its fossil remains and of particular value as a source of regional palaeoclimatic information. Historically, lithostratigraphic reconstructions have been performed mainly for successions of the central and southern parts of the basin, resulting in a lithostratigraphic scheme that is not applicable to the northernmost regions. In particular, the northeastern deposits of the Marília Formation (Serra da Galga and Ponte Alta members) reveal lithological, stratigraphic, and palaeontological differences from southeastern and northwestern counterparts (Echaporã Member). Nevertheless, these deposits are considered as a single lithostratigraphic formation in the literature. To address this problem, this study demonstrates how the northeastern deposits of the Marília Formation do not show affinity to the rest of the unit. A more suitable lithostratigraphic model is proposed for the northeastern succession as a distinct and independent unit. Lithofacies and palaeopedological analysis, combined with lithostratigraphic mapping of the northeastern deposits, reveal 11 distinct lithofacies and three pedotypes over an area of ~450 km2. Sedimentary facies and pedotypes were assigned to six interbedded architectural elements: (a) type 1 channel fill, (b) type 2 channel fill, (c) type 3 channel fill, (d) interchannels, (e) palaeosols, and (f) calcrete beds. The succession is interpreted as a distributive fluvial system with overall direction of flow to the NNW, and which developed under the influence of a semiarid climate regime. This contrasts with deposits of the southeastern and northwestern Marília Formation, previously suggested to be of fine-grained aeolian affinity with interbedded poorly channelised deposits assigned to an aeolian sand sheet environment. By revising the existing lithostratigraphic scheme for the northeastern deposits, and contrasting them with laterally equivalent strata, this work demonstrates how the previously named Serra da Galga and Ponte Alta members reveal a unique set of lithological, architectural, and genetic signatures that permits to separate them from the Marília Formation. Finally, a new lithostratigraphic classification for the unit is proposed: the Serra da Galga Formation, whose deposition relates to an ancient distributive fluvial system.Fil: Soares, Marcus Vinícius Theodoro. Universidade Estadual de Campinas; BrasilFil: Basilici, Giorgio. Universidade Estadual de Campinas; Brasil. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: da Silva Marinho, Thiago. Universidade Federal do Triângulo Mineiro; BrasilFil: Martinelli, Agustín Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Marconato, André. Universidade Federal de Ouro Preto; BrasilFil: Mountney, Nigel Philip. University Of Leeds.; Reino UnidoFil: Colombera, Luca. University Of Leeds.; Reino UnidoFil: Mesquita, Áquila Ferreira. Universidade Estadual de Campinas; BrasilFil: Vasques, Julia Tucker. Universidade Estadual de Campinas; BrasilFil: Junior, Francisco Romero Abrantes. Universidade Estadual de Campinas; BrasilFil: Ribeiro, Luiz Carlos Borges. Universidade Federal Do Triangulo Mineiro; Brasi

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data