J. Sánchez−Ducuara , E. Gómez−Arias , E.L. Mejia−Toro , G. Rodríguez−Ospina , J.C. Herrera−Casseres
{"title":"Thermal conductivity of sedimentary rocks in two exploratory wells drilled in the Paipa geothermal area, Colombia","authors":"J. Sánchez−Ducuara , E. Gómez−Arias , E.L. Mejia−Toro , G. Rodríguez−Ospina , J.C. Herrera−Casseres","doi":"10.1016/j.jsames.2025.105843","DOIUrl":"10.1016/j.jsames.2025.105843","url":null,"abstract":"<div><div>The Paipa geothermal area, located in the Eastern Cordillera of the Colombian Andes, is a sedimentary basin with promising potential for future geothermal energy development due to its favorable geological conditions. Over the last years, multiple geophysical, geological, and geochemical studies have highlighted the area's subsurface thermal anomalies and structural features. As a result of this growing body of evidence, the Colombian Geological Survey (SGC) selected the Paipa region for exploratory drilling and drilled two wells to investigate its geothermal potential. This study has two main objectives: first, to present the thermal conductivity results obtained from laboratory measurements on core samples and demonstrate how well log data can be used to correct these values to reflect in situ conditions; and second, to assess the use of well-logging data (gamma ray, neutron porosity, and temperature) as a practical method to estimate rock thermal conductivity in geothermal wells. For validating these estimates against 58 measured rock samples using four mixing models (harmonic, arithmetic, geometric, and root mean) within a shale-sand-fluid framework. Temperature corrections were applied separately to the solid and fluid phases. For the well AGT-01, the geometric mean model provided the best agreement with the measured thermal conductivity, yielding a value of 0.11 <span><math><mrow><mi>W</mi><mo>/</mo><mi>m</mi><mi>K</mi></mrow></math></span>. In contrast, for the well AGT-02, the harmonic mean model showed the best fit, with a conductivity value of 0.18 <span><math><mrow><mi>W</mi><mo>/</mo><mi>m</mi><mi>K</mi></mrow></math></span>.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105843"},"PeriodicalIF":1.5,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364695","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}
Marco Pfeiffer , Valentina Cárdenas , Elizabeth Rovira , Jimmy Cordero , Tamara Pailamilla , Joaquín Vergara , Paula Maldonado , Oscar Seguel , Nicolás Soto , Juan Luis García
{"title":"Uncovering the relict periglacial landscapes of the central Chile Andes: Soil formation and polar desert features at 33°S","authors":"Marco Pfeiffer , Valentina Cárdenas , Elizabeth Rovira , Jimmy Cordero , Tamara Pailamilla , Joaquín Vergara , Paula Maldonado , Oscar Seguel , Nicolás Soto , Juan Luis García","doi":"10.1016/j.jsames.2025.105839","DOIUrl":"10.1016/j.jsames.2025.105839","url":null,"abstract":"<div><div>This study investigates periglacial relict surfaces in the central Chile Andes (33°S), focusing on soil formation and geomorphic features. These surfaces, preserved since preglacial periods, provide a unique record of long-term landscape evolution. We analyzed 12 sites with a mean elevation of ∼3200 m a.s.l., spanning 2200–4200 m, with periglacial and polar desert features appearing predominantly above ∼3300 m a.s.l. Fieldwork involved describing and sampling soil profiles, characterizing physical and chemical properties, and documenting geomorphic features across the altitudinal transect. Our results highlight desert pavements, vesicular horizons, patterned ground, and ice wedges, features indicative of a distinctive high-altitude periglacial dominated climatic regime. Soil formation trends across altitudinal vegetational belts show the development of mollic and argillic horizons, shaped by prolonged aridity and minimal glacial erosion, suggesting they are pre-Quaternary surfaces. In-situ mechanical weathering appears central to the genesis of pavements and vesicular horizons. The presence of these features at high elevations, together with evidence of periglacial processes, underscores the distinctive environmental conditions of the high elevation central Chilean Andes. Despite precipitation exceeding ∼500 mm y<sup>−1</sup> -higher than in Antarctica or the Arctic-the soils display features typical of polar deserts <em>sensu lato</em>. These findings provide insights into the long-term climatic evolution of mid-latitude high-altitude environments, offering a new perspective on the region's climatic history and the formation of polar desert-like features in a non-polar setting. More broadly, they highlight the significance of mid-latitude high-altitude environments for interpreting polar desert-like features outside polar regions.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105839"},"PeriodicalIF":1.5,"publicationDate":"2025-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364646","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}
Daniela Schievano de Campos, Thiago Tavares Vidoca do Nascimento, Ana Paula Dechen Rodrigues, Pablo Vidal-Torrado
{"title":"The dynamic of rare earth elements in the context of multiple bauxitization cycles: Evidence in the Southern Espinhaço Range (Southeastern Brazil)","authors":"Daniela Schievano de Campos, Thiago Tavares Vidoca do Nascimento, Ana Paula Dechen Rodrigues, Pablo Vidal-Torrado","doi":"10.1016/j.jsames.2025.105840","DOIUrl":"10.1016/j.jsames.2025.105840","url":null,"abstract":"<div><div>Rare earth elements (REE) are widely used in the paleoenvironmental interpretation of bauxitic and ferruginous duricrusts as they are sensitive to the physical-chemical conditions and may record environmental changes in situations of intense weathering. In the Southern Espinhaço Range in Southeast Brazil, two bauxite targets of the scaffolded bauxitization model type evolved from hematitic phyllite and presented disparate REE behavior. In addition to the REE, the two targets have other chemical and mineralogical differences, which suggests paleoenvironmental differences during their evolution. This study investigates these differences using the mass balance of the LREE and HREE and Ce/Ce∗, La/Y, and (La/Yb)<sub>N</sub> ratios to identify the main environmental characteristics associated with the evolution of these targets. Factorial analysis of the behavior patterns of major and trace elements, and mineralogy was used to identify cluster patterns among samples from the two targets. Contrasting behavior was found between the targets, and the REE indicate an acidic, reductive environment for one of the targets, and an alkaline/acidic, reductive environment for the other target. These differences suggest that the over layering of bauxitization cycles is responsible for adding or obliterating geochemical characteristics to make the bauxitic system complex for the interpretation of paleoenvironments.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105840"},"PeriodicalIF":1.5,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145325990","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":"Depositional setting and facies of the late Holocene sediments at the Atrato River Delta, Colombia","authors":"Liliana Betancurth , Julio E. Cañón","doi":"10.1016/j.jsames.2025.105825","DOIUrl":"10.1016/j.jsames.2025.105825","url":null,"abstract":"<div><div>The Atrato River Delta (ARD), situated in the Gulf of Urabá along the Colombian Caribbean coast, is shaped by both fluvial and marine influences. Characterized by high sediment discharge from a small, tectonically active, and rain-rich catchment, the ARD exhibits sedimentation rates comparable to other tropical and subtropical deltas worldwide. This study analyzes late Holocene and modern sedimentation patterns using six shallow sediment cores extracted from the Delta's swamps and bays. A multiproxy approach—incorporating grain size, mineralogy, organic matter content, geochemistry, and luminescence dating—reveals a suite of facies ranging from coarse sand to clay, indicative of mid-to high-energy transport, sediment reworking, and relative sea-level fluctuations. These findings challenge the conventional classification of the ARD as a fluvially dominated delta. The presence of organic matter throughout the sequences suggests a gradual transition from fluvial channel infill to estuarine and marine deposition. The fine sediments of the Atrato River have contributed to the development of an extensive deltaic floodplain. Three distinct phases of sedimentary dynamics are identified: (1) a marine-dominated phase during relative sea-level rise in the late Holocene (∼1680 ± 130 to 870 ± 70 a); (2) a transitional fluvial–tidal regime (∼740 ± 60 to 550 ± 50 a); and (3) a fluvial-dominated phase associated with relative sea-level fall (∼550 ± 70 a to present). These insights shed light the formative processes of this tropical “bird-foot” delta and offer new perspectives for paleoenvironmental and sedimentary research in the Caribbean region of South America.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105825"},"PeriodicalIF":1.5,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364649","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":"Arc segmentation identified from analysis of spatial distribution of volcanoes. Calibration of methodology in the north Andes","authors":"Edgardo Cañón-Tapia","doi":"10.1016/j.jsames.2025.105835","DOIUrl":"10.1016/j.jsames.2025.105835","url":null,"abstract":"<div><div>Volcanism along subduction zones in general, and the arc of the north Andes in particular, have been depicted as either randomly distributed or as displaying some degree of segmentation. Before attempting to determine how common is arc segmentation in a large number of arcs worldwide, it is therefore important to test the reliability of the method that will be used for the analysis. In this work the steps followed to implement an unbiased search for clusters in individual arcs are explained in detail. The proposed protocol uses as only input the coordinates of the volcanic edifices in the north Andes arc. The obtained results illustrate that the segmentation of this arc that was inferred based on structural and tectonic lines of evidence can be well reproduced from the analysis of the spatial distribution of vents. The influence of age in the database is also illustrated, showing that restricting analyses to only Holocene volcanism might not suffice to detect volcano segmentation. The proposed protocol will be useful to guide future investigations concerning the possible existence of a sub clustered structure in other volcanic arcs around the world.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105835"},"PeriodicalIF":1.5,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364163","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}
F. Chacón-Hernández , L. Quintanar , I. Rodríguez-Rasilla
{"title":"Spatiotemporal characterization of crustal anisotropy in the source area of the 2017 puebla-morelos earthquake","authors":"F. Chacón-Hernández , L. Quintanar , I. Rodríguez-Rasilla","doi":"10.1016/j.jsames.2025.105837","DOIUrl":"10.1016/j.jsames.2025.105837","url":null,"abstract":"<div><div>Spatiotemporal variations in seismic anisotropy are investigated using local crustal and upper mantle earthquakes with magnitudes greater than M<sub>w</sub> 2.5, occurred in the Puebla-Morelos region of Central Mexico, an area historically impacted by significant seismic activity. Data were collected from five permanent stations located more than 70 km from the epicentral area of the 2017 Puebla-Morelos earthquake (M<sub>w</sub> 7.1). Shear-wave splitting parameters were obtained from 276 seismic waveforms recorded between 2011 and 2020, providing insights into crustal anisotropy behaviors. The overall dominant fast polarization (ϕ) is oriented WNW86.7°ESE, which deviate from the regional maximum stress field (S<sub>HR max</sub>), typically oriented NE-SW to ENE-WSW. Instead, it aligns with the WNW-ESE structural trend parallels to the Middle American Trench, suggesting that subduction-derived tectonic fabric exert strong control on seismic anisotropy in the region. Anisotropic observations reveal notable spatial differences in both tectonic and anisotropic frameworks across the study area. The northern-northwestern sector appears more susceptible to stress-induced anisotropy. This sector also exhibits elevated crack densities, with normalized delay times (δt km<sup>−1</sup>) reaching up to 30 ms km<sup>−1</sup>, and exhibit monoclinic and transverse isotropic features, suggesting a greater capacity for structural deformation. In contrast, the western and eastern sectors display anisotropy primarily controlled by pre-existing structural features with orthorhombic features. Although ϕ measurements in these sectors align with S<sub>HR max</sub>, there is not conclusive evidence of stress-induced anisotropy. These patterns reveal that static stress changes affecting crustal anisotropy during the preseismic and coseismic stages of the Puebla-Morelos mainshock were not uniformly expressed across the region. Such changes appear to be more clearly captured in the northern-northwestern sector, highlighting a greater sensitivity to the accumulation of structural deformation prior to a major earthquake. Overall, these findings underscore the heterogeneous response of different crustal blocks to evolving stress conditions.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105837"},"PeriodicalIF":1.5,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326190","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}
Pablo Grosse , María Luisa Ochi Ramacciotti , Daniel Bertin , Álvaro Rodrigo Iriarte Ibañez , Néstor Jiménez , Matthieu Kervyn
{"title":"Geomorphometric database and analysis of Late Oligocene to Holocene composite volcanoes of the Central Andes of Bolivia, Chile and Argentina","authors":"Pablo Grosse , María Luisa Ochi Ramacciotti , Daniel Bertin , Álvaro Rodrigo Iriarte Ibañez , Néstor Jiménez , Matthieu Kervyn","doi":"10.1016/j.jsames.2025.105832","DOIUrl":"10.1016/j.jsames.2025.105832","url":null,"abstract":"<div><div>The Central Andes of South America contains hundreds of composite volcanoes with a wide variety of morphologies and ages, making it a unique region to investigate the spatial, temporal and geomorphological evolution of arc volcanism. We present and analyze a database that includes new spatial, geomorphic and morphometric data, as well as relative and absolute age data, for 645 Late Oligocene to Holocene composite volcanoes and large lava domes of the Central Andes of Bolivia, Chile and Argentina (17.1°–28.1°S). The included volcano edifices show a great morphometric diversity, from small simple cones with volumes ≤1 km<sup>3</sup> to complex, long-lived massifs with volumes of up to 300 km<sup>3</sup>. Quaternary edifices have lifespans mostly between 0.2 and 1.8 Myr, and average growth rates typically between 10 and 80 km<sup>3</sup>/Myr. The spatial distribution of volcanism highlights the influence of arc-oblique structures and of some first-order, continental and oceanic crustal anomalies. Cumulative bulk volumetric output estimates are of 12,000 km<sup>3</sup> for the last ∼11.6 Myr, with an average output rate of 0.86 km<sup>3</sup> per km of arc per Myr. Volumetric output peaks are centered at ∼19°, 21.8°, 24.2°, 25.5°, and 26.8°S, each with variable inputs in terms of age and position with respect to the present-day arc. The database offers new opportunities for more detailed analyses of the spatial and/or temporal evolution of volcanism along different segments of the arc and for a variety of regional analyses in combination with geophysical, tectonic or geochemical datasets.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105832"},"PeriodicalIF":1.5,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364648","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}
A. Massenzio , M.C. Lamberti , A. Chiodi , I. Burgos , G. Viti , F. Tassi , M. Agusto , J. Viramonte
{"title":"Carbon isotopic composition of CO2 in interstitial soil gases from Southern Puna calderas, Central Andes: Decoding hydrothermal and shallow sources","authors":"A. Massenzio , M.C. Lamberti , A. Chiodi , I. Burgos , G. Viti , F. Tassi , M. Agusto , J. Viramonte","doi":"10.1016/j.jsames.2025.105828","DOIUrl":"10.1016/j.jsames.2025.105828","url":null,"abstract":"<div><div>The Southern Puna hosts active geothermal systems associated with various volcano-magmatic settings, among which caldera-hosted systems stand out as promising targets for geothermal exploration. This study focuses on two key calderas that currently exhibit active geothermal manifestations: Cerro Blanco Caldera (CBC), the youngest caldera system in the region (4.2 ka), and Cerro Galán Caldera (CGC), the largest caldera system in this sector of the Andes. The main objective was to decode the contributions of deep (hydrothermal) and shallow (biogenic and atmospheric) sources to diffuse CO<sub>2</sub> emitted from the soil, using a three-component mixing model. The results revealed the presence of these three sources: deep hydrothermal, shallow biogenic, and atmospheric. At CBC and CGC, high CO<sub>2</sub> concentrations (>5000 ppm) and δ<sup>13</sup>C-CO<sub>2</sub> values around −5 ‰ (vs. V-PDB) indicate a dominant hydrothermal contribution. In contrast, more <sup>13</sup>C-depleted values (down to −21.3 ‰) and lower CO<sub>2</sub> concentrations suggest microbial or soil respiration origin. Analysis of profiles in the soil revealed considerable variability, with deviations from the expected theoretical patterns in some cases. These anomalies are attributed to a combination of factors, including atmospheric contamination during sampling in low-permeability soils, isotopic fractionation under low gas flow conditions and local secondary processes, such as carbonate dissolution/precipitation. Despite these complexities, the combination of isotopic and concentration analysis robustly confirms the presence of hydrothermal CO<sub>2</sub> in the shallow soil gases in both calderas providing valuable insights for geothermal exploration and volcanic monitoring in the Central Andes.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105828"},"PeriodicalIF":1.5,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145364647","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}
Leonel Schap , Mercedes Barros , Leonardo Strazzere , Daniel A. Gregori , Joaquín Lorenzo Angaroni , Tomás Danei , Mauro Geraldes , José L. Fernández Turiel
{"title":"The Arroyo tembrao stock: implications for the Gondwana magmatism in the eastern North Patagonian region","authors":"Leonel Schap , Mercedes Barros , Leonardo Strazzere , Daniel A. Gregori , Joaquín Lorenzo Angaroni , Tomás Danei , Mauro Geraldes , José L. Fernández Turiel","doi":"10.1016/j.jsames.2025.105831","DOIUrl":"10.1016/j.jsames.2025.105831","url":null,"abstract":"<div><div>The Permian Arroyo Tembrao Stock, part of the Pailemán Plutonic Complex, is located within the Northeastern Gondwana magmatic belt of the eastern North Patagonian region, Argentina.</div><div>The rock is an I-type granitoids, plotting in some diagrams as A-type granites. The normalized diagram to primordial mantle values indicates the possible involvement of the upper Continental crust in generating this Stock, with a design similar to those observed in magmatic arc zones. The melting of greywacke and basaltic rocks could produce the magma that generated the Arroyo Tembrao Stock, with ages of crystallization of 263.7 ± 0.6 Ma and 280.8 ± 2.2 Ma.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105831"},"PeriodicalIF":1.5,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145325989","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}
José Arthur do Nascimento Ramalho, Karina Patrícia Vieira da Cunha, Matheus Natan Ferreira Alves de Sousa, Caio Victor Macêdo Pereira, Lara Fernandes de Medeiros, Sofia Luiza Inácio da Silva, Carlos Wilmer Costa
{"title":"Assessment of surface runoff, accelerated erosion, and diffuse pollution potential in the Potengi River Watershed, Rio Grande do Norte, Brazil","authors":"José Arthur do Nascimento Ramalho, Karina Patrícia Vieira da Cunha, Matheus Natan Ferreira Alves de Sousa, Caio Victor Macêdo Pereira, Lara Fernandes de Medeiros, Sofia Luiza Inácio da Silva, Carlos Wilmer Costa","doi":"10.1016/j.jsames.2025.105829","DOIUrl":"10.1016/j.jsames.2025.105829","url":null,"abstract":"<div><div>This study aimed to analyze the potential for surface runoff, accelerated erosion, and diffuse pollution in the Potengi River Basin (PRB), with a focus on identifying priority areas for conservation and restoration. An integrated Multi-Criteria Decision Analysis (MCDA) methodology was utilized within a Geographic Information System (GIS) environment. This approach incorporated various geoenvironmental attributes, including geological units, slope, thickness of unconsolidated materials, permeability, drainage density, surface water storage features, landform shapes, rainfall, land use and land cover, soil erodibility, soil texture, and concentrations of available phosphorus (P) and organic matter (OM). The results indicated that the PRB is primarily characterized by low to moderate surface runoff potential, covering 98.44 % of the area. However, approximately 60.91 % of the area is at high risk of accelerated erosion due to factors such as steep slopes and highly erodible sandy soils. Additionally, around 38.96 % of the watershed area exhibited a high to very high potential for diffuse pollution, emphasizing the vulnerability of water resources and the need for integrated management strategies, including the restoration of riparian vegetation. The analyses highlighted the importance of implementing measures to mitigate the impacts of erosion and pollution, thereby promoting environmental sustainability within the PRB. Furthermore, the methodology was applied successfully to characterize these processes and can be replicated for other watersheds, especially in semiarid regions where environmental pressures and natural vulnerabilities are significant. Methodological innovations in acquiring certain attributes, such as surface water storage features, drainage density, and soil erodibility, along with the use of sand and clay fractions to assess soil texture in map algebra operations, contributed to the quality of cartographic representation. This improvement allows for a more accurate and well-founded spatial analysis.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"168 ","pages":"Article 105829"},"PeriodicalIF":1.5,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145326003","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}