Article
Geosciences, Multidisciplinary
Ji-In Jung, Julie A. Bowles
Summary: Microbialites are layered organosedimentary deposits that can preserve high-resolution magnetic field variations. Studies on modern and ancient microbialites show that their magnetization records are consistent with expected field directions, suggesting a detrital origin for the recorded remanent magnetization, with acquisition timing close to sediment deposition.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Biology
Steffen H. Buttner, Eric W. Isemonger, Michelle Isaacs, Deon van Niekerk, Rachel E. Sipler, Rosemary A. Dorrington
Summary: This study reports living cyanobacterial phosphatic stromatolites in a supratidal freshwater environment, resembling fossilized stromatolites but forming in a lower phosphorus concentration setting than previously thought. Thus, the findings challenge the use of phosphatic stromatolites as a proxy for high ambient phosphate concentrations in ancient environments.
Article
Geology
Brooke E. Vitek, Erica P. Suosaari, Amanda M. Oehlert, Christophe Dupraz, Clement G. L. Pollier, R. Pamela Reid
Summary: This article describes the internal structure of microbialites in Hamelin Pool, Shark Bay, Western Australia, and their evolution process. Observations and analysis of microbialite samples reveal the relationship between accretionary mat type and microfabric, and present a conceptual framework for understanding the evolution of modern microbialites.
DEPOSITIONAL RECORD
(2023)
Article
Environmental Sciences
Zachary A. Siders, Andrew J. Westgate, Kathryn R. Bell, Heather N. Koopman
Summary: The diving behavior of basking sharks, the largest filter-feeding planktivore, is influenced by their location, prey distribution, and thermal stratification. The study identified five different strategies of vertical movement behavior in basking sharks, which were influenced by the ratio of V-shaped to U-shaped movements and the depth of subsurface movements. The sharks exhibited considerable inter- and intra-individual variability in their diving behavior, which was related to the time of year and tidal phase. However, more information about the copepod prey field is needed to fully understand the variability. The technique used in this study can be applied to other species and requires fewer subjective delineations of diving behavior compared to other classification techniques.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Yi Zhang, Jian Li, Long Chen, Yi Wei, Qiang Shi, Dong-Ge Wang, Qing-Ming Wu, Liao-Yuan Song, Meng Tian, Hong-Wei Kuang, Yong-Qing Liu, Kaarel Mand, Hua-Qing Bai, Zi-Liang Liu, Yu-Chong Wang, Da-Wei Qiao, Wen-Jun Zhu
Summary: This study provides a detailed description of the characteristics and growth modes of five types of manganese stromatolites, with results showing that they primarily grew in biostromes in shoal and lagoon environments, and were syngenetic with oncolites and oolites in carbonate ramps. Manganese stromatolites can be categorized into three forms: stratiform, columnar (including branched and columnar types), and stratiform-columnar. The shapes of the stromatolites are mainly controlled by water depths and hydrodynamic strengths, with columnar stromatolites further divided based on diameter into micro-columnar and columnar columns.
JOURNAL OF PALAEOGEOGRAPHY-ENGLISH
(2021)
Article
Multidisciplinary Sciences
Jorge D. Carrillo-Bricemo, Edwin-Alberto Cadena
Summary: This study reports and describes a new species of Strophodus, a hybodontiform shark, based on isolated teeth collected in ValanginianHauterivian rocks of the Rosa Blanca Formation in Colombia. It also describes fragmented teeth assigned to Strophodus sp. from the same formation. The discovery of this new species expands our understanding of the paleogeographic distribution and paleodiversity of hybodontiform sharks in South America, particularly in the Cretaceous period.
Article
Geology
Nils Schlueter, Frank Wiese, Manuel Diaz-Isa, Tobias Puettmann, Ireneus Walaszczyk
Summary: This article describes eight echinoid species found in Upper Cretaceous marl-limestone alternations from a temporary outcrop near the village of Mompia in northern Cantabria, Spain. Most of the reported echinoids are likely endemic to the working area. An integrated stratigraphic approach using ammonites, inoceramid bivalves, calcareous nannofossils, and stable carbon isotopes localizes the echinoid assemblage in the upper middle and lower upper Santonian.
CRETACEOUS RESEARCH
(2023)
Article
Geosciences, Multidisciplinary
Arnaud Gallois, Daniel Bosence, Peter Burgess
Summary: This study utilizes seismic and borehole data, coupled with outcrop logging and correlations, to establish a new tectono-sedimentary model demonstrating the control of extensional faults and relay ramps on the distribution of lacustrine carbonate facies.
Article
Environmental Sciences
Wulan Koagouw, Zainal Arifin, George W. J. Olivier, Corina Ciocan
Summary: This study found several aquatic contaminants, including pharmaceuticals like paracetamol, in seawater samples collected from effluent-dominated sites in Indonesia. Nutrient parameters exceeded Indonesian standards and some metals were present. High concentrations of paracetamol were detected, raising concerns about environmental risks and impact on nearby shellfish farms. Further investigations are suggested due to pharmaceuticals being considered emerging contaminants.
MARINE POLLUTION BULLETIN
(2021)
Article
Geology
Paul Enos, Elias Samankassou
Summary: The Lofer cyclothems of the Alpine Upper Triassic share many similarities with Holocene sediments of Florida Bay, including symmetrical cycles and similar depositional textures and structures. These similarities suggest that sedimentation patterns at a small scale may be independent of the global climate regime, providing important insights into the Triassic depositional environment and future evolution of modern environments.
Article
Environmental Sciences
Gilmara F. Eca, Ana C. R. Albergaria-Barbosa, Manuel M. de Souza, Patricia G. Costa, Adriele S. Leite, Gilberto Fillmann, Vanessa Hatje
Summary: The study evaluated the occurrence of 24 Polycyclic Aromatic Hydrocarbons (PAHs) in sediments and shellfish of Todos os Santos bay (BTS, Brazil), indicating moderate contamination from pyrogenic activities. Different species showed varying bioaccumulation factor (BAF) for total PAHs, with high molecular weight compounds enriched in species living in fine sediment and low molecular weight compounds enriched in species living in the roots of mangrove trees. High concentrations of PAHs raise concerns about shellfish quality and seafood consumption safety.
MARINE POLLUTION BULLETIN
(2021)
Article
Environmental Sciences
Natasha Klasios, Hannah De Frond, Ezra Miller, Meg Sedlak, Chelsea M. Rochman
Summary: The study found microplastics and other anthropogenic microparticles in bivalves from San Francisco Bay, with significant variations in abundance between different sites, and no correlation between the number of microparticles and PAH concentrations. Bivalves may be suitable as bioindicators for microplastic levels in sediment, but not in surface water.
ENVIRONMENTAL POLLUTION
(2021)
Article
Multidisciplinary Sciences
Erica P. Suosaari, R. Pamela Reid, Christophe Mercadier, Brooke E. Vitek, Amanda M. Oehlert, John F. Stolz, Paige E. Giusfredi, Gregor P. Eberli
Summary: Hamelin Pool in Western Australia is a modern microbial carbonate factory, with the largest living marine stromatolite system, producing a significant amount of microbial sediments annually. Erosion and degradation of weakly lithified microbial mats in the pool lead to the production of sand-sized micritic grains, contributing to nearly a quarter of the total sediment. These modern examples provide valuable insight for identifying sedimentary deposits of microbial origin in the geologic record.
SCIENTIFIC REPORTS
(2022)
Article
Biochemistry & Molecular Biology
Mohamad Bazzi, Nicolas E. Campione, Per E. Ahlberg, Henning Blom, Benjamin P. Kear
Summary: Through geometric morphometric analysis of shed teeth, this study found that sharks maintained stable dental morphology in most clades following the end-Cretaceous mass extinction event, but apex predator species characterized by triangular blade-like teeth were impacted by selective extinctions.
Article
Microbiology
Miguel Iniesto, David Moreira, Guillaume Reboul, Philippe Deschamps, Karim Benzerara, Paola Bertolino, Aurelien Saghai, Rosaluz Tavera, Purificacion Lopez-Garcia
Summary: The formation of microbialites is influenced by environmental factors, and the microbial communities associated with carbonate-rich sedimentary rocks vary across different lakes but exhibit functional stability. Specific bacteria and eukaryotes coexist in microbialites from different lakes, potentially playing important roles in microbialite formation.
ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Biology
Carolina Zabini, Ana Beatriz Furtado-Carvalho, Dermeval Do Carmo, Mario Luis Assine
Summary: This study presents a new occurrence of a discinoid brachiopod in the Iapo and Vila Maria Formations of the Parana Basin, indicating a possible connection between the Soom Shale in the Cape Basin, South Africa, and the Parana Basin during the Early Paleozoic. The new species, Kosoidea australis sp. nov., is characterized by a convexo-plane shell and a marked posterior triangular pedicle opening. The presence of this genus in different locations suggests insights into ancient earth configurations such as the supercontinent Gondwana.
HISTORICAL BIOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Fernando F. Vesely, Mario L. Assine, Almerio B. Franca, Paulo S. G. Paim, Sidnei P. Rostirolla
Summary: Tunnel valleys are subglacial incisions formed by meltwater erosion, commonly found in Pleistocene and Ordovician glacial records but poorly recognized in late Paleozoic strata. The Lapa sandstone in eastern Paraná Basin, southern Brazil, is an exhumed valley-fill succession formed as the infilling of a tunnel valley cut beneath an advancing ice margin onto poorly consolidated, mud-rich sediments. The recognition of tunnel valleys may help in estimating the extent of glaciation across the region and guiding exploration for hydrocarbon traps.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Rodrigo Cerri, Lucas Warren, Filipe G. Varejao, Alex J. Choupina A. Silva, Cristiano Lana, Mario L. Assine
Summary: This study examines the sedimentary records of two rift basins in northeastern Brazil and confirms the age relationships and provenance patterns between them through detrital zircon U-Pb age analysis. The results highlight a key change in source areas from rift to initial deposition of the intracratonic basin.
GEOLOGICAL MAGAZINE
(2022)
Article
Geosciences, Multidisciplinary
Carolina Zabini, Matheus Denezine, Livia C. da S. Rodrigues, Livio R. de O. Goncalves, Rodrigo R. Adorno, Dermeval do Carmo, Mario L. Assine
Summary: This study focuses on the boundary between the Ordovician and Silurian in the Paraná Basin in Brazil, examining a fossil assemblage that suggests a Hirnantian age. The taphonomic signatures and facies associations point to a pro-glacial environment followed by post-glacial conditions in an offshore setting. The low faunal diversity indicates marine connections between different basins.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2021)
Article
Geography, Physical
Patricia Colombo Mescolotti, Fabiano do Nascimento Pupim, Francisco Sergio Bernardes Ladeira, Andre Oliveira Sawakuchi, Amanda Santa Catharina, Mario Luis Assine
Summary: This study investigated a 200-km section of the Sao Francisco River in northeast Brazil, characterized different geomorphological zones, and dated them using optically stimulated luminescence. The research identified at least four phases of sediment deposition, three phases of incision, and two phases of dune field stabilization in the last 100 ka. The study suggests that the aggradation and incision phases on the Sao Francisco River were likely controlled by multi-millennial precipitation changes, possibly related to precession cycles.
QUATERNARY SCIENCE REVIEWS
(2021)
Article
Geosciences, Multidisciplinary
Lucas Warren, Andre Santiago Martins de Andrade, Filipe Giovanini Varejao, Paloma Promenzio, Mauricio G. M. Santos, Luciano Alessandretti, Mario Luis Assine
Summary: The Araripina Formation in the Araripe Basin represents deposition in a distributive fluvial system following regional tectonic subsidence. It is characterized by two depositional sequences with various sedimentary facies associations, reflecting a tectonically active interior basin with periodic flooding events and distinct source areas. The lower sequence facies associations indicate deposition in a meandering distributive fluvial system, while the upper sequence suggests intense tectonic activity in a large distal floodbasin dominated by suspension, with a change in paleodrainage patterns after the Albian period.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Victor Carvalho Cabral, Patricia Colombo Mescolotti, Filipe Giovanini Varejao
Summary: A detailed sedimentologic and stratigraphic investigation was conducted in the Coraca region of northern Minas Gerais state, Brazil, to position the vertebrate assemblage in the stratigraphy and understand the changing characteristics of the lacustrine system over time.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Lucas Verissimo Warren, Filipe Giovanini Varejao, Fernanda Quaglio, Lucas Inglez, Fernanda Buchi, Marcello Guimaraes Simoes
Summary: The influence of microbial communities on sedimentary dynamics is significant. The oldest evidence of microbially-induced sedimentary structures (MISS) in South America has been found in Brazil, indicating the interaction among flows, marine substrate, and benthic microbial communities. The vertical growth of microbial communities affects sediment cohesion and stability, increasing the potential for preserving bedforms and delicate features on bedding surfaces.
BRAZILIAN JOURNAL OF GEOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Rodrigo Cerri, Lucas Warren, Christopher J. Spencer, Filipe G. Varejao, Paloma Promenzio, George L. Luvizotto, Mario L. Assine
Summary: The Early Paleozoic of the NE Brazilian sedimentary basins are crucial for understanding the primeval depositional environments and paleogeography of Western Gondwana. This study focuses on the Cariri Formation in the Araripe Basin and reveals its depositional age and source areas. The results suggest that the Cariri Formation started to deposit after the Late Cambrian, with primary sources from the Brasiliano Orogeny and secondary contributions from the Cambrian sources.
JOURNAL OF SOUTH AMERICAN EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
F. G. Varejao, L. Warren, M. G. Simoes, R. Cerri, L. Alessandretti, M. G. M. Santos, M. L. Assine
Summary: Soft-sediment deformation structures (SSDSs) are commonly found in the geological record, especially in siliciclastic deposits. However, researchers have discovered that different types of SSDSs also develop in sedimentary successions containing carbonate rocks. By combining facies analysis with detailed outcrop descriptions, seismic and non-seismic generated structures can be identified. The origin and impact of these deformation mechanisms are discussed in the context of offshore petroleum reservoirs in the Brazilian Pre-Salt successions.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Geography, Physical
T. G. L. Souza, S. A. Matos, F. G. Varejao, M. G. Rodrigues, A. C. Ribeiro, B. T. Freitas, L. Warren, M. L. Assine, M. G. Simoes
Summary: We report the discovery of the Amargosa Biota in the Marizal Formation of the Central Tucano Sub-Basin in Northeast Brazil. Exceptionally preserved fossils were found in a mud-dominated succession called Amargosa Bed. These fossils include ostracods, spinicaudatan carapaces, palaemonid shrimps, fish, and plant remains, and were found in high concentration on certain bedding planes. The presence of poorly biomineralized organisms and soft-bodied parts suggests that the fossils were preserved under unusual conditions, possibly caused by abrupt changes in water parameters.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geosciences, Multidisciplinary
M. G. Rodrigues, F. G. Varejao, S. A. Matos, F. T. Fuersich, L. V. Warren, M. L. Assine, M. G. Simoes
Summary: This study explains the sedimentary environment, bed-by-bed accumulation history, and carbonate microfacies of the Aptian Romualdo Formation in the Araripe Basin, Brazil, revealing high-frequency details in a restricted shallow sea setting. The shell beds are multi-event carbonate deposits generated by the superposition of various processes.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Geography, Physical
G. C. Antunes, L. V. Warren, J. Okubo, T. R. Fairchild, F. G. Vareja, G. J. Uhlein, L. Inglez, D. G. Poire, A. M. Bahniuk, M. G. Simo
Summary: The integrated analysis of the Lower Permian Santa Rosa de Viterbo giant stromatolite field in Brazil reveals a detailed paleoenvironmental model for this occurrence, demonstrating the influence of changing hydrodynamic conditions, water depth, and terrigenous input on the growth of the giant stromatolites. The increase in microbial activity, nutrient supply, and primary productivity towards the top of the succession is reflected in higher 813C values. The shift towards a less restricted environment is consistent with the morphological changes in the stromatolites, indicating increasing water depth. The deposition of the stromatolites under high salinity conditions is supported by the presence of smooth lamination, exclusively coccoidal microbial community, and fossil content.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geography, Physical
Filipe G. Varejao, Lucas Warren, Luciano Alessandretti, Mariza G. Rodrigues, Claudio Ricomini, Mario Assine, Leonardo F. Cury, Frederico M. Faleiros, Marcello G. Simoes
Summary: A large number of siliceous mounds in the upper part of the Permian Teresina Formation in the Paraná Basin, Brazil are identified as hot springs. These mounds show remarkable features indicating a hydrothermal origin. The study provides important insights into the formation of syn-depositional hydrothermally precipitated silica in ancient sedimentary basins.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geology
Luciano Alessandretti, Lucas V. Warren, Filipe G. Varejaeo, Raul Rassi, Mauricio G. M. Dos Santos, Mariana N. M. Silva, Fernando R. Honorato, Michele J. T. Estrada, Joao V. O. Cunha
Summary: During the last stages of Gondwana fragmentation, large areas of the newly formed South American continent were covered by extensive deserts. In the southwestern part of the Sanfranciscana Basin in central Brazil, synsedimentary magmatism occurred in direct association with soft-sediment deformation structures in aeolian sandstone and siltstone facies. These deformation features, including liquefaction, fluidization, and brittle behavior, were triggered by the uplift of the Paranaiba High during Late Cretaceous aeolian sedimentation.
JOURNAL OF SEDIMENTARY RESEARCH
(2023)