Journal of South American Earth Sciences最新文献

{"title":"Facies-driven correlations based on rock porosity for the assessment of geomechanical properties of carbonate rocks in Santos Basin","authors":"Alexandre Scussel Zanatta ,&nbsp;Roberto Quevedo ,&nbsp;Deane Roehl ,&nbsp;Bruno R.B.M. Carvalho ,&nbsp;Cláudio H.B. de Resende","doi":"10.1016/j.jsames.2025.105557","DOIUrl":"10.1016/j.jsames.2025.105557","url":null,"abstract":"<div><div>Rock mechanical properties are essential for building reliable geomechanical models. Usually, such properties are assessed through laboratory tests. However, representative rock samples of deep formations are difficult to obtain owing to several issues. As an alternative, empirical correlations based on physical parameters such as rock porosity or the unconfined compressive strength, are commonly adopted. Yet, there is considerable data scattering, in particular for reservoirs from Brazilian pre-salt oil fields which are highly heterogeneous. In this study, we propose empirical correlations based on porosity for assessing mechanical rock parameters for carbonate rocks in the Mero field located in Santos Basin. First, a classification based on depositional processes was performed, identifying four carbonate facies: Coquinas, Reworked, Shrubs, and Laminites. The available data were collected from laboratory tests performed in samples taken from wells drilled in the Mero field. The data based on unconfined compressive strength and porosity were grouped for each proposed facies. Then, the corresponding elastic and strength parameters are assessed from triaxial compression tests. Finally, the obtained mechanical parameters are correlated to the porosity, establishing empirical correlations for each facies. The results show that such correlations can be used to assess rock mechanical properties in Pre-salt Brazilian carbonates, contributing to the building of more reliable geological reservoir models.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105557"},"PeriodicalIF":1.7,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mandibular pathologies in Notiomastodon platensis (Ameghino, 1888): Insights into chronic osteomyelitis and its implications for the health of Pleistocene proboscidean from South America","authors":"Carlos Alberto Luna ,&nbsp;Alfredo E. Zurita ,&nbsp;Sebastián Sabater ,&nbsp;Fernando Henrique de Souza Barbosa ,&nbsp;Matías Forno ,&nbsp;Dimila Mothé","doi":"10.1016/j.jsames.2025.105552","DOIUrl":"10.1016/j.jsames.2025.105552","url":null,"abstract":"<div><div><em>Notiomastodon platensis</em> (Ameghino, 1888) is the most widely distributed proboscidean species in the Quaternary of South America. Over the past few decades, various pathological conditions of the axial skeleton have been described in this species; however, no cases of mandibular diseases has been reported to date, despite their common occurrence in extant proboscideans. In this study, we document signs of mandibular diseases in two <em>N. platensis</em> individuals from the Pleistocene of Argentina. The first individual exhibits bony swelling, cloaca and solid periosteal reaction, likely associated with a fractured molar. The second specimen shows extreme molar crown wear, pulp cavity exposure, and the formation of a periapical abscess, likely resulting from pulp infection due to dental attriction. Both cases, though differing in origin, are diagnosed as secondary chronic osteomyelitis of the mandible, an infectious process that would have impaired feeding, potentially leading to malnutrition, weakness, and contributing to the mortality of these individuals.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"161 ","pages":"Article 105552"},"PeriodicalIF":1.7,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143898450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Primary and diagenetic controls on the quality of Albian carbonate reservoirs of the Tubarão Martelo area, southern Campos Basin, Brazil","authors":"G. Armelenti ,&nbsp;K. Goldberg ,&nbsp;F.B. Amarante ,&nbsp;J.P.F. Ferronato ,&nbsp;J. Kuchle ,&nbsp;R. Alvarenga ,&nbsp;C.M.S. Scherer ,&nbsp;A.C. Bastos ,&nbsp;J.L.D. Alves ,&nbsp;J.C. Conceição ,&nbsp;L.F. De Ros","doi":"10.1016/j.jsames.2025.105550","DOIUrl":"10.1016/j.jsames.2025.105550","url":null,"abstract":"<div><div>Albian carbonate reservoirs have been an attractive target for oil exploration and production in the Campos Basin for several decades. However, the heterogeneous reservoir quality in the sourthern portion of the basin has represented a considerable challenge. The deposits in the Tubarão Martelo area are high energy oolitic calcarenites, and moderate energy oncolitic and peloidal calcarenites and calcirudites and hybrid arenites. Nine reservoir petrofacies were defined in the Quissamã Formation limestones. Their main diagenetic processes were eogenetic calcite cementation and replacement by blocky dolomite, mechanical and chemical compaction, eogenetic and mesogenetic dissolution. Primary composition and texture were less important than diagenesis in conditioning reservoir quality. Partial early cementation by calcite rims and sintaxial overgrowths limited the compaction of some oolitic and oncolitic calcarenites, preserving interparticle primary porosity. However, interparticle porosity was totally obliterated where cementation was abundant, as observed in the oncolitic calcirudites. Hybrid arenites also show very limited porosity, owing to strong compaction. The Búzios Member dolostones locally show good porosity, but their permeability is very limited, owing to dolomite cementation (overdolomitization), which severely reduced the intercrystalline porosity, isolating their moldic pores. The main phase of dissolution in the Quissamã limestones occurred during eogenetic infiltration of meteoric waters. A second dissolution phase took place during burial, by the percolation of evolved fluids through fractures and stylolites. Understanding the depositional and diagenetic factors that controlled the reservoir quality of Campos Basin Albian carbonates is paramount for the exploration of new accumulations, as well as for increasing oil recovery from the producing fields.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105550"},"PeriodicalIF":1.7,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"2D geological processes modeling of Aptian Pre-salt carbonate reservoirs: Assessing a conceptual depositional model in the Sapinhoá Field, Santos Basin, Brazil","authors":"Henrique Picorelli Ladeira Dutra,&nbsp;Patrick Führ Dal’ Bó","doi":"10.1016/j.jsames.2025.105549","DOIUrl":"10.1016/j.jsames.2025.105549","url":null,"abstract":"<div><div>Recently discovered Pre-salt reservoirs along the Brazilian Eastern margin are among the industry's most challenging oil fields due to their high heterogeneity. Recent studies indicate that the deposition of facies was primarily governed by chemical and physical processes within lakes formed by thermal subsidence, which developed prior to the breakup of Gondwana during the Lower Cretaceous. However, debate persists regarding whether these lakes were shallow or deep, the extent to which the structures observed today in seismic data were prominent at the time of deposition, and the nature of the lateral connectivity of the deposits in relation to the vertically stacked sedimentation cycles observed in well data. The aim of this study is to develop a quantitative 2D model for the upper Barra Velha Formation (BVF) based on a conceptual framework, providing new constraints within the boundaries of the available data and the physical laws implemented in the model. This model simulates sediment deposition in the upper BVF of the Sapinhoá Field over time. The topography used for the simulation was constructed from a reconstructed, flattened seismic horizon, allowing for the simulation of a shallow lake with no major paleo-relief variations. Well data were used to interpret flooding and evaporation cycles that controlled sediment deposition and stacking patterns. Following this method, a seismic forward model was created, enabling comparisons between the features observed in seismic data and those produced by the shallow lake simulation model. This quantitative approach reproduces the expected stacking pattern and offers insights into the lateral connectivity of the deposits in line with the chosen conceptual depositional model, while maintaining strong correlation with well data and lake fluctuation cycles interpreted through a high-resolution stratigraphic analysis. The simulation results support the hypothesis of a shallow lake within the study area for the deposition of the upper BVF, thus prompting further discussion on the depositional settings of the Pre-salt interval, especially regarding the updip portions of the Santos Basin.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105549"},"PeriodicalIF":1.7,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143894796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The postcranial skeleton of Luangwa sudamericana (Traversodontidae: Cynodontia) from the Middle-Late Triassic of southern Brazil","authors":"Nicole L. Souza ,&nbsp;Fernando Abdala ,&nbsp;Francesco Battista ,&nbsp;Ana M. Ribeiro","doi":"10.1016/j.jsames.2025.105546","DOIUrl":"10.1016/j.jsames.2025.105546","url":null,"abstract":"<div><div>Traversodontidae represent a highly successful lineage of Triassic Cynodontia, renowned for their taxonomic diversity and abundance. Characterized by their labiolingually expanded gomphodont postcanines, traversodontids also display a wide range of body sizes. Despite their evolutionary, paleobiological and biostratigraphy significance, studies on their postcranial anatomy remain limited. Here, we provide the first description of the postcranium of <em>Luangwa sudamericana</em>, based on the specimen MCN-PV 10500, recovered from the Middle-Late Triassic, Bortolin site, Santa Maria Supersequence. The specimen includes partially disarticulated vertebrae, ribs, and elements of shoulder and pelvic girdles, as well as hindlimb and forelimb bones. Specialized rib morphologies closely resembling the different stages of the ribs of the African species <em>L.</em> <em>drysdalli</em> are present. The humerus also shares comparable proportions and anatomical features with <em>L. drysdalli</em>. Characteristics as prominent lesser tuberosity, robust entepicondyle and supracondylar crest were observed in the humerus of MCN-PV 10500, <em>L. drysdalli</em> and <em>L. sudamericana</em> (MCN-PV 10314). Similar morphology of anterior and posterior process of the ilium, distinctive femoral greater trochanter, and anterodorsally deflected femoral head are additional similarities that support a close relationship between MCN-PV 10500 and <em>L. drysdalli</em>. Taphonomic and sedimentological evidence, as well as the preservation mode, suggest that the specimen was preserved in fluvial floodplain deposits, with variable bone surface preservation reflecting distinct depositional and diagenetic conditions. Although studies about the postcranial anatomy of cynodonts are quite limited the shared features of MCN-PV 10500 and <em>L. drysdalli</em> supports the assignment to <em>L. sudamericana</em>.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105546"},"PeriodicalIF":1.7,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geological evidences of the Zonda palaeo-river megafan, Central Andes of Argentina (33°S)","authors":"Javier Oropeza ,&nbsp;Stella M. Moreiras ,&nbsp;Daniela M. Kröhling ,&nbsp;François De Vleeschouwer ,&nbsp;Gael Le Roux","doi":"10.1016/j.jsames.2025.105545","DOIUrl":"10.1016/j.jsames.2025.105545","url":null,"abstract":"<div><div>The Subtropical Andean foreland basin sedimentation of Argentina was marked by fluvial megafans during the Late Quaternary. However, at the latitude 33°S, where an active orogenic front is advancing across the foreland basin, the regional Quaternary fluvial dynamics are still overlooked. This is mainly due to thick aeolian mantle overlying these fluvial deposits preventing classical field geological studies. In this research, remote sensing and morphometric indices analysis coupled with field data allowed us to tackle to detect an ancient fluvial megafan. This Distributive Fluvial System was associated with the Zonda palaeoriver which was related to the temporary confluence of the Mendoza and Tunuyán rivers during part of the Quaternary. Landforms linked to the megafan were detected using ALOS PALSAR DEMs and SRTM. The Zonda megafan covers an area of ca. 7096 km² and is characterized by a distributive pattern of wide fluvial palaeochannels interspersed with aggradational lobes and terminal splays. Scarce exposed outcrops show fine-grained fluvial sediments containing pumice clasts. Geochemical analysis showed that these clasts originate from the Maipo volcano (∼450–150 ka. BP). Furthermore, the span life of the Zonda paleoriver until the Late Pleistocene was constrained by exploratory AMS dating. Based on our findings, we propose that the evolution of the Zonda fluvial system is driven by a complex interaction between climatic and tectonic forcings.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105545"},"PeriodicalIF":1.7,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to “Application of sensing techniques for quantifying CO2 flux and dynamics in environments affected by the Fundão dam collapse, Mariana, Brazil” [J. S. Am. Earth Sci. 146 (2024) 105099 – pages 1–9]","authors":"Heitor Paiva Palma ,&nbsp;Danilo César de Mello ,&nbsp;Márcio Rocha Francelino ,&nbsp;Daniela Schmitz ,&nbsp;Gustavo Vieira Veloso ,&nbsp;Ana Paula Marinho Santos ,&nbsp;Daniel Nunes Krum ,&nbsp;André Thomazini ,&nbsp;Elpídio Inácio Fernandes-Filho ,&nbsp;Carlos Ernesto Gonçalves Reynaud Schaefer ,&nbsp;José A.M. Demattê","doi":"10.1016/j.jsames.2025.105532","DOIUrl":"10.1016/j.jsames.2025.105532","url":null,"abstract":"","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105532"},"PeriodicalIF":1.7,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uncertainty analysis of sediment size estimations in gravel-bed reaches in Southern Brazil","authors":"F.C. Zambrano ,&nbsp;Masato Kobiyama ,&nbsp;Gabriel Narváez Campo","doi":"10.1016/j.jsames.2025.105544","DOIUrl":"10.1016/j.jsames.2025.105544","url":null,"abstract":"<div><div>Understanding sediment size distribution is essential for comprehending the hydrogeomorphological dynamics of mountain river systems. Manual and automated techniques for sampling surface sediments in gravel-bed rivers can generate uncertainties naturally. This study aims to comprehend field-walking techniques (manual) and photogrammetric analysis (automation) by estimating uncertainties in sediment size distribution. Measurements were conducted at five sites along the Forromeco River in southern Brazil, including field pebble counting and UAV-based photogrammetry. To calculate the nominal diameter, field measurements provide three axes of the sediment, while photogrammetry only two. A binomial probability distribution model was applied to estimate the percentile confidence interval of sediment size, thus enabling an assessment of the uncertainty between the adopted techniques. Results indicate that 3-axis measurements generally yield smaller sediment sizes compared to 2-axis methods, reflecting the influence of the sediment shape on the shortest axis magnitude. Statistical analysis by site showed no differences between the nominal diameter computed with 3-axis or 2-axis. However, a four sites ensemble revealed discrepancies. Drone-derived measurements, while efficient, tended to overlook finer sediments and overestimate larger sizes, particularly in areas with vegetation obstacles. The present study highlights the importance of considering the sediment shape, sediment configuration and regional lithology when interpreting drone data. Overall, the 3-axis field pebble counting method provides more accurate sediment size characterization in mountain rivers like the Forromeco. This research contributes to the understanding of sediment dynamics in mountainous regions, aiding in the management of water and sediment resources, and mitigating flood-related disasters.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105544"},"PeriodicalIF":1.7,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climatic, anthropogenic and sea level influences on the vegetation landscape of a lagoonal system, over the last 3350 years","authors":"Victor Rocha Carvalho ,&nbsp;Adriana Leonhardt ,&nbsp;Felipe García-Rodríguez ,&nbsp;Andreia Souza Pereira de Ávila ,&nbsp;Silvia Regina Bottezini ,&nbsp;Débora Pimentel Diniz ,&nbsp;Marlon Carlos França ,&nbsp;Paula Dentzien-Dias","doi":"10.1016/j.jsames.2025.105535","DOIUrl":"10.1016/j.jsames.2025.105535","url":null,"abstract":"<div><div>This study explores the influence of dry and wet weather events, sea-level fluctuations, and anthropogenic activities on vegetation dynamics over the past 3,350 cal years BP. Sedimentological and palynological analyses were supported by radiocarbon (¹⁴C) and lead-210 (²¹⁰Pb) dating of a 110 cm sediment core (GAR 1) extracted from the northwest sector of the Garzón Lagoon, Uruguay. Lagoon is an intermittently closed system, periodically opening to the sea, with a maximum depth of 5 m. Two different time windows are presented: part of the late Holocene and the last 150 years. Between 3,350 and 2,345 cal years BP, sea levels were high, and the lagoon maintained a broad connection to the sea, favoring halophytic vegetation, including Amaranthaceae and Poaceae, indicative of a salt marsh environment. After 2,345 cal yr BP, an increase in freshwater algae <em>Botryococcus</em> spp., resulting from a brief eutrophication episode, and a pronounced rise in arboreal taxa, particularly the Moraceae/Urticaceae group, signaled a shift towards a more freshwater-influenced system. The contemporary period (1841–2021 CE) is marked by pronounced climatic variability, alternating wet and dry episodes, and intensified anthropogenic activities, including <em>Pinus</em> spp. afforestation and expanded agricultural practices. These human interventions significantly impacted sedimentation rates and influenced the Garzón lagoon's ecological dynamics.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105535"},"PeriodicalIF":1.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143877192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corrigendum to ‘Pervasive crustal reworking along the proto-Andean margin of northern Peru and southern Ecuador: Insights from U-Pb, geochemical, and isotopic analyses of zircon’ [J. S. Am. Earth Sci. 158 (2025) 105502]","authors":"Leidy Carolina Sandoval Espinel ,&nbsp;Cesar Witt ,&nbsp;Massimiliano Zattin ,&nbsp;Marc Poujol ,&nbsp;Olivier Bruguier ,&nbsp;Massimo Chiaradia ,&nbsp;Mauricio Bermudez","doi":"10.1016/j.jsames.2025.105536","DOIUrl":"10.1016/j.jsames.2025.105536","url":null,"abstract":"","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"160 ","pages":"Article 105536"},"PeriodicalIF":1.7,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}