Journal of South American Earth Sciences最新文献

{"title":"Structural Andean evolution of the western border of the central Fiambalá basin, Catamarca province, Argentina","authors":"Ernesto O. Cristallini ,&nbsp;Agostina D'Ascenzo ,&nbsp;Renata N. Tomezzoli ,&nbsp;Melina E. Gugliotta ,&nbsp;Nicolás Braun","doi":"10.1016/j.jsames.2025.105901","DOIUrl":"10.1016/j.jsames.2025.105901","url":null,"abstract":"<div><div>Aquí se presenta una interpretación de las principales estructuras geológicas cenozoicas aflorantes en la cuenca de Fiambalá, también conocida como Bolsón de Fiambalá provincia de Catamarca, Argentina. La compresión andina deformó las secuencias sedimentarias neógenas formando una serie de corrimientos dispuestos en sentido ∼ N-S con vergencia hacia el este. A partir de la información relevada en el campo, integrada con estudios geológicos previos e imágenes satelitales, se elaboró una sección estructural balanceada con el fin de caracterizar la deformación del área y se realizó una reconstrucción palinspástica a partir del cual se calculó un acortamiento total de 6.13 km, equivalente al 18 % para la región.</div></div><div><h3>ABSTRACT</h3><div>We present an interpretation of the main Cenozoic geological structures outcropping in the Fiambalá Basin, also known as Bolsón de Fiambalá, Catamarca Province, Argentina. Andean compression deformed the Neogene sedimentary sequences, forming a series of thrusts arranged in a north-south direction with eastward convergence. Based on own field collected data, combined with previous geological studies and satellite images, a balanced structural section was constructed to characterize the deformation of the area. A palinspastic reconstruction was performed, from which a total shortening of 6.13 km was calculated, equivalent to an 18%, for the studied region.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105901"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694509","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 megadrought modulation of sediment transfer in the Volcán River basin (33°S), semi-arid Andes","authors":"M. San Juan ,&nbsp;T. Villaseñor ,&nbsp;D. Dintrans","doi":"10.1016/j.jsames.2025.105903","DOIUrl":"10.1016/j.jsames.2025.105903","url":null,"abstract":"<div><div>Mountain catchments are dynamic sedimentary systems where climate variability significantly affects geomorphic processes and sediment connectivity. This study investigates the processes of sediment generation and transfer in the Volcán River basin in central Chile's semi-arid Andes, a region impacted by a prolonged megadrought since 2010. We combined geomorphological mapping, sediment connectivity modelling using the Index of Connectivity (IC), and sediment geochemistry analysis of suspended sediments collected during spring-summer season of 2022–2023. Geomorphological mapping identified seven distinct morphogenetic environments (morphostructural, volcanic, glacial, fluvial, denudational, glacial ice and anthropogenic), each contributing variably to sediment transfer. IC analysis revealed spatial heterogeneity in sediment connectivity, with higher values in fluvial and denudational domains and lower values in glacial and volcanic areas. Geochemical analysis of rare earth elements (REE) in suspended sediments indicated that Cenozoic volcanic formations, especially from subglacial sources, are the primary sediment contributors under current hydrological conditions, with Mesozoic units contributing episodically during high-magnitude events like debris flows. Under this scheme, surficial glacial and volcanic morphogenetic domains act as sediment buffers due to their distance to the main fluvial channels as well as morphology that promotes sediment accumulation. In contrast, high melt rates of the glaciers in the valley enhance subglacial connectivity to the fluvial network in the context of the megadrought, while mass wasting events act as sources for short-term sediment pulses during high runoff events. These findings highlight how sediment coupling and provenance in mountain basins are modulated by both the current megadrought and extreme hydrometeorological events. The results provide insights for hazard assessment and sediment management in mountainous regions experiencing climatic stress.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105903"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694606","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":"Unusual number of large tectonic earthquakes before and during the birth of the Paricutin monogenetic volcano. Did they trigger, maintain, and boost the volcanic long-lasting activity from 1943 to 1952?","authors":"D. Legrand ,&nbsp;M. Perton ,&nbsp;M.G. Gómez-Vasconcelos ,&nbsp;P. Larrea","doi":"10.1016/j.jsames.2025.105895","DOIUrl":"10.1016/j.jsames.2025.105895","url":null,"abstract":"<div><div>Volcanoes can be described as falling somewhere a large spectrum ranging from polygenetic systems, which are constructed through multiple, long-lived eruptive phases, to monogenetic systems, which usually form during a single eruptive event. Within this context, several decades of observations on Earth have shown that close and strong tectonic earthquakes can precede large eruptions of polygenetic volcanoes. In contrast, only a few close and large earthquakes have been reported before the birth of new monogenetic volcanoes, since the latter are rare. Here, we describe the unusually high number of large tectonic earthquakes that preceded the birth of the Paricutin monogenetic volcano in Mexico in 1943. Thirteen large tectonic earthquakes occurred in the near field during the 20-year period spanning the decade before the birth of Paricutin to the end of its eruption, whereas only one earthquake occurred within ten years after the eruption ended. This clustering of large tectonic earthquakes in space and time before and during the eruption of Paricutin is unusual for this region of Mexico. The significant difference in the number of tectonic earthquakes before, during, and after the eruption strongly suggests that Paricutin's birth and growth are related to these earthquakes. They may have changed the stress tensor near Paricutin's location, facilitating magma to migrate towards the surface and sustaining Paricutin's eruption for nine years - an unusually long period for a monogenetic volcano. We propose that changes in static and quasi-static stress fields, resulting from local faults, local tectonics, and static displacement fields generated by near-field earthquakes, may have triggered and boosted the Paricutin's eruption. In addition, we suggest that the dynamic stress field generated by the waves emitted by earthquakes may have altered magma pathways towards the surface prior to and during the Paricutin's eruption.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105895"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694506","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":"Isotope-informed water sources and recharge mechanisms in a tropical karst environment of the Talgua River Basin, Honduras","authors":"Jorge Cardona-Hernández ,&nbsp;Germain Esquivel-Hernández ,&nbsp;Lucilena Rebelo Monteiro ,&nbsp;Ricardo Sánchez-Murillo ,&nbsp;Marycel E.B. Cotrim ,&nbsp;Rolando Sánchez-Gutiérrez ,&nbsp;Christian Birkel ,&nbsp;Tania Peña-Paz ,&nbsp;Laura Benegas-Negri","doi":"10.1016/j.jsames.2025.105891","DOIUrl":"10.1016/j.jsames.2025.105891","url":null,"abstract":"<div><div>Understanding groundwater recharge mechanisms in karst zones is critical for preserving water supply, establishing water-use policies, and monitoring water pollution. In this study, we analyzed the isotope composition (δ²H and δ¹⁸O) of rainfall, surface water, and groundwater in the Talgua River basin in northeastern Honduras between August 2019 and December 2023. The main goal was to study the relationship between rainfall inputs and recharge mechanisms in a complex karstic environment, characterized by high rainfall seasonality and variable land use. The δ¹⁸O and δ²H relationship in rainfall resulted in a significant local meteoric water line of δ²H = 7.68 ± 0.08·δ¹⁸O + 9.47 ± 0.42 (N = 223, r² = 0.97, p &lt; 0.001). HYSPLIT air mass trajectory and cluster analysis using δ¹⁸O and deuterium excess (<em>d</em>-excess) revealed that moisture sources in the Talgua River basin originated mainly from the Caribbean Sea (89 %) with minimal contributions from the Pacific Ocean and the Gulf of Mexico (11 %). Recharge is mainly driven by heavy, isotopically depleted rainfall during the May–November (wet season), as indicated by the rainfall to groundwater (P/GW) ¹⁸O/¹⁶O ratios. <em>d</em>-excess and the line-conditioned excess (LC-excess) values indicate substantial meteoric inputs during the wet season, reflecting a recycled-moisture signal that contributes to recharge, with only minor evapoconcentration effects. This study systematically provides essential insights into rainfall, surface water, and groundwater interactions in the poorly understood karstic regions of Central America. It advances our understanding of tropical karst hydrological processes, such as moisture transport and recharge mechanisms, and provides valuable information for water resource evaluation and management.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105891"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145646039","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":"Petrogenesis of a highly contaminated magmas by ascent through a thick continental crust: The case of Sairecabur volcano, Central Andes","authors":"Camila Loaiza ,&nbsp;Benigno Godoy ,&nbsp;Nataly Freire ,&nbsp;Osvaldo González-Maurel ,&nbsp;Inés Rodríguez Araneda ,&nbsp;Petrus le Roux ,&nbsp;Juan Figueroa","doi":"10.1016/j.jsames.2025.105898","DOIUrl":"10.1016/j.jsames.2025.105898","url":null,"abstract":"<div><div>Magmas in the Central Andes have evolved through fractional crystallization and crustal assimilation, operating at different crustal levels during their ascent through the ∼70 km-thick continental crust. Sairecabur stratovolcano, located within the Altiplano–Puna Volcanic Complex (APVC; 21°–24° S) of the Central Andean subduction zone, is stratigraphically divided into three units: Pre-Caldera Lavas (PRECL - Pleistocene), Post-Caldera I Lavas (POCIL - Upper Pleistocene), and Post-Caldera II Lavas (POCIIL - Holocene). These volcanic products range from 55 (basaltic andesite) to 63 (dacite) wt.% SiO₂. In particular, Sairecabur shows a negative correlation between SiO₂ wt.% and Eu/Eu∗, with Eu/Eu∗ values &lt; 1, indicating the key role of plagioclase during late-stage magma differentiation. A deep-crustal garnet signature - though not prominent - cannot be excluded, which was overprinted by shallow differentiation and assimilation. Over the past 10 Ma, APVC magmas have been affected by significant crustal contamination, linked to crustal thickening during the Andean orogeny and localized processes. This trend is observed in all units of Sairecabur, where ⁸⁷Sr/⁸⁶Sr ratios of erupted products range from 0.707057 to 0.708667. This suggests a substantial crustal assimilation of a parental Andean-type magmas (⁸⁷Sr/⁸⁶Sr ratio ∼0.705), which was generated by an early stage of magmatic differentiation at lower crustal levels (MASH zone). Petrographic and geochemical data define three main mid-to-upper crustal evolutionary stages occurring afterwards: (1) an AFC stage in mid-to upper-crustal chambers, with 33–47 % AFC-type incorporation of felsic upper crustal material; (2) an intermediate stage of closed-system fractional crystallization involving plagioclase, pyroxene, amphibole, and biotite; and (3) a late-stage episode of magma mixing with shallow crustal melts, evidenced by glomeroporphyritic gabbroic aggregates and by trace-element trends and scatter accompanying advanced differentiation.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105898"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737896","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":"Integrated analysis of geomechanical facies and diagenetic controls on brittleness and reservoir quality in pre-salt carbonates","authors":"Maria Liceth Cabrera Ruiz,&nbsp;Alessandro Batezelli","doi":"10.1016/j.jsames.2025.105893","DOIUrl":"10.1016/j.jsames.2025.105893","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Understanding carbonate rocks and their geomechanical behavior is essential for optimizing hydrocarbon production. In carbonate reservoir, defining geomechanical facies offers an innovative approach to predict mechanical heterogeneity and supporting hydraulic fracturing design at the field scale. This study aims to classify the Barra Velha Formation into geomechanical facies by integrating mechanical analysis with rock characterization, in order to evaluate how mechanical strength, rock type, diagenetic processes influence the brittleness index and, consequently, reservoir integrity and development. This study utilized a comprehensive database from the Búzios Oil field, including conventional logs, image logs, leak-off tests, repeat formation tests, nuclear magnetic resonance data, mineral spectroscopy, X-ray diffraction, thin section and core photographs, and seismic data. The geomechanical models were developed using dynamic geomechanics and calibrated with well-test data. In addition, a Bayesian classification technique was used to define geomechanical facies. Carbonate rocks were classified according to Gomes et al. (2020). The in-situ stress distribution indicates that the current stress regime in the field is dual, ranging between normal and strike-slip, with a pore pressure gradient greater than the hydrostatic one. The maximum horizontal stress azimuth has two predominant orientations, approximately 80° and 270°. This orientation shows variations compared to the paleo-stress directions, which were aligned with the regional tectonic framework. Four geomechanical facies were defined, with mechanical strength ranging from intermediate to very low (Compacted, Brittle-Reservoir, Ductile-Sealing, and Semiductile-Reservoir), and an overall classification accuracy of 82 %. Compacted facies exhibit the highest mechanical strength and have a high content of quartz, feldspar, and mica due to grainstone texture with a high degree of cementation, very low porosity, and nearly zero permeability. In contrast, Semiductile-Reservoir facies, which displays the lowest mechanical strength, has the highest weight fraction of carbonate and is dominated by in-situ rocks, such as spherulitestones, these exhibit the best porosity and permeability properties, evidence of dissolution processes, and low cementation. Conversely, Ductile-Sealing facies present higher clay fraction values, microporosity, and stylolite development, which coincide with Mudstone lithologies. Regarding brittleness analysis, Compacted facies showed a higher propensity to develop drilling-induced tensile fractures and had the highest IB values. On the other hand, Ductile-Sealing facies were more prone to the development of breakouts, while Semiductile-Reservoir was prone to low amplitude fractures associated with the lowest IB values. In conclusion, this geomechanical study has provided valuable insights into the influence of diagenetic overprinting processes on carbonate rocks, wh","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105893"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694505","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":"Compressional tectonics related to Fuegian orogeny: Insights from AMS and structural geology in Navarino Island, Chile","authors":"Roberto González-Vidal ,&nbsp;Felipe Tapia ,&nbsp;Fernando Poblete ,&nbsp;Matías Peña ,&nbsp;Esteban Salazar ,&nbsp;Valentina Ríos","doi":"10.1016/j.jsames.2025.105899","DOIUrl":"10.1016/j.jsames.2025.105899","url":null,"abstract":"<div><div>Navarino Island is located in the southernmost part of South America, within the Central Belt of the Fuegian Orogen. The shortening of the geological units observed on the island is believed to be related to a compressional event during the closure of the Rocas Verdes Basin. However, the full extent of this relationship remains unclear due to accessibility challenges and the apparent change in the stratigraphic records both north and south of the Beagle Channel. In this study, we integrate anisotropy of magnetic susceptibility (AMS) with structural observations across turbiditic sandstones and mudstones from the Lower Cretaceous Yahgan Formation. We analyzed thirty new sampling sites located along the northern coast of the island and the Dientes de Navarino mountain group. The AMS data exhibited predominantly oblate magnetic fabrics, with P′ values ranging from 1.02 to 2.22. The ellipsoid orientations correlated well with the structural features, particularly cleavage (S₁) and fold axes. High P′ values and tectonic fabric types were concentrated in the western part of the island. A transition from a tectonic fabric with lower anisotropy degrees to a more sedimentary fabric was observed towards the east and south. These findings reflect a W-E deformation gradient consistent with the island's structural features, including an overprinting cleavage family (S₂) restricted to the island's northwest. This study highlights the utility of AMS in elucidating strain directions and reconstructing deformation histories in complex orogenic settings.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105899"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694608","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":"Structural and groundwater exploration in the Guayatayoc salt flat basin (Puna Oriental Jujeña, northwest Argentina), using multiple geophysical techniques","authors":"María Florencia Ahumada ,&nbsp;Marcelo Gonzalez ,&nbsp;Franco Clavel Alvarado ,&nbsp;Héctor P.A. García ,&nbsp;Federico Lince Klinger ,&nbsp;Francisco Ruiz","doi":"10.1016/j.jsames.2025.105917","DOIUrl":"10.1016/j.jsames.2025.105917","url":null,"abstract":"<div><div>The Guayatayoc salt flat basin, located in the northern sector of the Argentine Puna region (Jujuy province), stands out as one of the most promising areas for in depth geophysical research, focused on brine exploration. This region is considered one of the primary areas hosting several economically important lithium brine deposits. These results were obtained using gravimetry, audio-magnetotelluric (AMT), electrical resistivity tomography (ERT), magnetometry, and refraction seismic techniques. The main objective was to characterize the subsurface properties to infer the presence of clastic and/or evaporitic facies potentially carrying brines, as well as to identify marginal aquifers zones or freshwater sources that contribute to recharge and analyze the structural controls of the basin.</div><div>Two 2D geological models were developed, revealing a structurally segmented basin into high and low blocks, with three sub-basins delimited by Paleozoic-Cretaceous basement blocks uplifted by faults. A sedimentary unit with densities and electrical resistivity compatible with saturated sands and gravels, possibly carrying brackish water or clay-rich formation containing brines was modeled.</div><div>This work represents one of the few published studies that integrate multiple geophysical methodologies for the characterization of a salt flat basin located in the Puna region of Argentina. The use of multiple geophysical techniques promotes best practices in geophysical exploration and responsible resource management. This methodology can be replicated in other saline regions within the Lithium Triangle.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105917"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737898","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":"Genesis of the Rosa de Maio gold deposit, Tapajós Mineral Province, northern Brazil: Hydrothermal evolution and mineralization from geochemistry, mineral chemistry, 40Ar/39Ar geochronology, and sulfur isotopes","authors":"Pedro Victor F. de S. Alves ,&nbsp;Nilson F. Botelho ,&nbsp;Valmir da S. Souza ,&nbsp;Lys M. Cunha","doi":"10.1016/j.jsames.2025.105897","DOIUrl":"10.1016/j.jsames.2025.105897","url":null,"abstract":"<div><div>The Rosa de Maio deposit is a magmatic-hydrothermal gold deposit located in the northwestern Tapajós Mineral Province, within the south-central Amazonian Craton, northern Brazil. It is genetically linked to the Rosa de Maio Granite (<em>ca.</em> 1890 Ma), a high-K calc-alkaline and relatively oxidized intrusion associated with the late-to post-collisional continental arc magmatism of the Parauari Suite (1.89–1.87 Ga). Although the magmatic evolution of the deposit has recently been addressed, its hydrothermal evolution has not yet been investigated in detail. This study proposes that the Rosa de Maio deposit comprises two genetically related hydrothermal systems: a deeper system characterized by sodic, potassic, propylitic, and sericitic alteration, and a shallower, near-surface system marked by sericitic alteration and the development of a quartz stockwork system. Gold mineralization occurs in both systems, hosted within sericitic alteration zones and sulfide-rich quartz veins. In all cases, gold shows a consistent spatial association with sulfides, particularly pyrite. Muscovite from a quartz vein in the shallower system yielded a⁴⁰Ar/³⁹Ar plateau age of 1808.3 ± 7.1 Ma, interpreted either as the result of isotopic resetting during a younger thermal event or as evidence of a younger mineralizing magmatism not yet identified in the area. Sulfur isotope analyses of pyrite from both systems yielded δ³⁴S values between +0.5 and + 1.3 ‰, consistent with a dominantly magmatic sulfur source. Overall, the deeper system of the Rosa de Maio deposit shares several similarities with Au-rich porphyry-style deposits, whereas the shallower system likely represents a superimposed epithermal mineralization, now largely eroded.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105897"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145694508","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":"Transpressional deformation and block rotation in the Patagonian Broken Foreland: Multidisciplinary approach and future perspectives","authors":"Micaela García ,&nbsp;Joaquín Bucher ,&nbsp;Rodrigo Feo ,&nbsp;Manuel López ,&nbsp;Florencia Milanese ,&nbsp;Magdalena Tettamanti ,&nbsp;Leandro D’Elia ,&nbsp;Andrés Bilmes ,&nbsp;Juan R. Franzese","doi":"10.1016/j.jsames.2025.105911","DOIUrl":"10.1016/j.jsames.2025.105911","url":null,"abstract":"<div><div>The Patagonian Broken Foreland (PBF) comprises isolated, fault-bounded Neogene basins displaying intricate internal deformation patterns. Although previous studies emphasized reverse faulting along basin boundaries, the role of strike-slip deformation and intra-basin strain partitioning remains poorly constrained. Through a multidisciplinary approach combining structural analysis, paleomagnetic data, and Digital Outcrop Model analyses, this work investigates three key PBF basins: Paso del Sapo, Piedra del Águila, and Collón Cura. Results document widespread distributed deformation characterized by clockwise vertical-axis block rotation controlled by internal oblique-slip faults and inherited basement structures. In the Paso del Sapo Basin, rotations are most pronounced within internal blocks, transitioning to tilting toward basin boundaries. The Piedra del Águila Basin records localized block rotation linked to angular relationships between strata and abrupt dip changes related to tilting of internal structures. The Collón Cura Basin records sustained rotation in fault-bounded blocks that persisted until ∼10 Ma. The magnitude of block rotation decreases upward in stratigraphy, indicating a progressive deformation history. Kinematic data reveal a transpressional regime involving coeval strike-slip and reverse faulting, resulting in spatial variations in strain partitioning across the basins. These findings underscore the value of multidisciplinary approaches to fully characterize retroarc foreland deformation, including the often-overlooked strike-slip components.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"170 ","pages":"Article 105911"},"PeriodicalIF":1.5,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145737897","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}