Journal of South American Earth Sciences最新文献

{"title":"Schellwienella amazonensis (Orthotetida, Brachiopoda): New species of the genus in the Lochkovian of the Amazonas Basin (Manacapuru Formation), northern Brazil","authors":"Luiz Felipe Aquino Corrêa ,&nbsp;Maria Inês Feijó Ramos ,&nbsp;João Marcelo Pais de Rezende","doi":"10.1016/j.jsames.2024.105253","DOIUrl":"10.1016/j.jsames.2024.105253","url":null,"abstract":"<div><div>The Devonian was a critical period in the global evolution of brachiopods, during which the phylum reached its maximum diversity in the Emsian and experienced a significant decline during the Frasnian–Famennian, second only to the mass extinction of the Late Permian. The brachiopod fauna of the Manacapuru Formation (Lochkovian) was unknown until 2011, when a significant number of Rhynchonelliformea and Linguliformea samples were recovered during paleontological salvage at the Belo Monte hydroelectric plant in Vitória do Xingu, Pará, Brazil. This study aims to identify the Orthotetida from this salvage. The taxonomic study of the brachiopods from the Manacapuru Formation (Lochkovian) led to the recognition of a new species, <em>Schellwienella amazonensis</em> n. sp., Family Pulsiidae Cooper and Grante, 1974. <em>Schellwienella amazonensis</em> n. sp. and <em>Schellwienella marcidula</em> Amsden, 1958 originally described to the Bois d’Arc Formation (Lochkovian), USA are the oldest records of the genus. The genus <em>Schellwienella</em> was present throughout all stages of the Devonian, primarily in the Gondwana siliciclastic marine environments, transiting between temperate and polar latitudes, and disappeared in the Viséan (early Carboniferous) under warmer waters and carbonate platform conditions typical of low-latitude regions.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105253"},"PeriodicalIF":1.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658257","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":"Hydrochemistry and surface water - groundwater interactions in an anthropically disturbed mountain river (Sierras Pampeanas, central Argentina)","authors":"Verena A. Campodonico ,&nbsp;Andrea I. Pasquini ,&nbsp;Karina L. Lecomte ,&nbsp;Brenda Y. Alvarez ,&nbsp;M. Gabriela García","doi":"10.1016/j.jsames.2024.105251","DOIUrl":"10.1016/j.jsames.2024.105251","url":null,"abstract":"<div><div>The surface water - groundwater interactions in a small anthropically affected mountain watershed (Salsipuedes River) in the Sierras Pampeanas (central Argentina) were analyzed and quantified by means of ²²²Rn mass balance modeling, and its implications in hydrochemistry and water quality were examined. Surface waters, springs and groundwater were sampled during the 2021–2022 hydrological year, and the major dissolved composition was determined. The studied waters are alkaline, showing an evolution from medium mineralized (1.5 &lt; ∑⁺ &lt; 3 meq L⁻¹) to mineralized type (3 &lt; ∑⁺ &lt; 6 meq L⁻¹) downstream. In general, waters are of the bicarbonate - calcium type with no spatial or seasonal variations. This composition is mainly controlled by silicates weathering. ²²²Rn modeling indicates that near the headwaters the Salsipuedes River recharges the aquifer, losing 1.2% and 2.4% of its discharge during the dry and wet seasons, respectively. Downstream, the system changes its hydrological behavior and the river acts as a gaining stream; i.e, it receives groundwater inflow. The magnitude of this inflow varies seasonally, being greater in the wet season (1.5–2.2% of the total flow) than in the dry season (less than 0.25%) due to a rise in the water table level as a result of direct recharge of the phreatic aquifer. Anthropic influence is noticeable in nitrate and chloride concentrations, which are derived from domestic wastes and septic tanks. The highest concentrations of these ions in surface waters are found in the urbanized area, where the river stretch corresponds to a gaining stream, reflecting that even small amounts of groundwater inputs can alter the chemical composition of streams. A temporal analysis also showed a variable response of the system to the increasing anthropic pressure and climatic events such as ENSO, which affect not only water availability but also its quality, highlighting the vulnerability of small mountain watersheds.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105251"},"PeriodicalIF":1.7,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658259","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":"Metal concentration in bottom sediments for a tropical river, geological or anthropogenic source?","authors":"Aracelis Narayan ,&nbsp;Iván Horacio Esteves ,&nbsp;Militza Rodríguez ,&nbsp;Judith Rosales","doi":"10.1016/j.jsames.2024.105237","DOIUrl":"10.1016/j.jsames.2024.105237","url":null,"abstract":"<div><div>The study analyzes data from a survey of metal concentrations in bottom sediments from both margins (left and right) of the lower main channel of the Orinoco River. This study aims to analyze metal concentrations in the bottom sediments of the lower Orinoco River with different geological settings and anthropological sources. El Almacen (ALM), Las Galderas (G), Los Castillos de Guayana (C), Ciudad Bolivar (CB), and Ciudad Guayana (CG) were the sampling sites. Freshwater physicochemical parameters pH, conductivity, and DO were measured <em>in situ</em> at each sample site. Twenty-four bottom sediment samples were collected with an Eckman grab, dried, and sieved. Trace elements Pb, Cr, Cu, Cd, Ti, and Co were measured in sediments with grain sizes &lt;63 μm. Bottom sediment analysis followed EPA method 3050B (digestion with HNO₃ + HCl + H₂O₂). Statistical analyses included the Shapiro-Wilk test, Spearman correlation, Kruskal-Wallis test, and principal component analysis (PCA). Physicochemical parameters highlighted the marked difference between the left and the right river margins, reflecting the cross-channel heterogeneity due to the dissimilar geology and low horizontal mixing. Metal concentrations were generally low, with higher variations associated with urban and industrial sources. Pb, Cr, Cu, Cd, Ba, Ti, and Co concentrations did not generally indicate significant pollution, but potential contamination from sewage and industrial effluents was noted. The differences between the two river margins were common in all the sampling sites, reflecting the sources of water biochemistry related to geochemical origins in the Andes and the Guiana Shield, respectively. The study emphasizes the importance of sampling location within the river channel.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105237"},"PeriodicalIF":1.7,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658260","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":"Ordovician and Devonian microfacies of Sierra Agua Verde, central Sonora, Mexico: A new locality of the Nuia Province from Western Laurentia","authors":"André Becuar-Daniels,&nbsp;Rogelio Monreal,&nbsp;Francisco Javier Cuen-Romero,&nbsp;Héctor Arturo Noriega-Ruiz,&nbsp;Juan José Palafox-Reyes","doi":"10.1016/j.jsames.2024.105208","DOIUrl":"10.1016/j.jsames.2024.105208","url":null,"abstract":"<div><div>The Lower Ordovician carbonate rocks exposed in the Tuntunudé hill north of the Sierra Agua Verde, northeast of the town of Mátape, in central Sonora, consists of intraformational breccia, conglomeratic limestone, sandy limestone and limestone, which are overlain by a mixed succession of quartz sandstone and dolomitic sandstone. This succession is in turn unconformably overlain by an Upper Devonian sequence of dolomitic limestone, marl, conglomeratic limestone and sandy dolomite. The Lower Ordovician rocks contain abundant bioclasts of gastropods, brachiopods, trilobites, echinoderms, and sponges. Their microfacies show a marine medium to low energy environment, with sedimentation dominated by distal tempestites in laminar stages and intraclast debris formation during deposition. The depositional paleoenvironment corresponds to a marine middle-to-outer ramp. These strata are characterized by conodonts belonging to the <em>Oepikodus communis</em> and <em>Reutterodus andinus</em> biozones, as well as cyanobacteria incertae sedis <em>Nuia sibirica</em>. Devonian rocks overlying the Ordovician strata contain bioturbation and abundant bioclasts of echinoderms, brachiopods, bryozoans, gastropods, chaetetiform sponges, stromatoporoids; and also, colonial corals like <em>Hexagonaria attenuata</em>, <em>Phillipsastrea hennahii</em> and <em>Phillipsastrea jachowiczi</em>, monothalamous foraminifera like <em>Vicin</em><em>e</em><em>sphaera</em> sp., monoserials such as <em>Tikhinella measpis</em> and planispiral such as <em>Nanicella gallowayi</em>. The microfacies show a high-energy environment in marine tropical shallow open-sea lagoonal waters, with ooids and reef building organisms.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105208"},"PeriodicalIF":1.7,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658256","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":"Phosphatization in the São Pedro and São Paulo Archipelago (SPSPA), Equatorial Atlantic, Brazil: Insights from guano leaching and chemical weathering","authors":"Eduardo Baudson Duarte ,&nbsp;Angélica Fortes Drummond Chicarino Varajao ,&nbsp;Fábio Soares Oliveira ,&nbsp;Christophe Renac ,&nbsp;Carlos Ernesto Gonçalves Reynaud Schaefer ,&nbsp;Eduardo Osório Senra","doi":"10.1016/j.jsames.2024.105234","DOIUrl":"10.1016/j.jsames.2024.105234","url":null,"abstract":"<div><div>This research explores the phosphatization process in the São Pedro and São Paulo Archipelago (SPSPA), located in the Equatorial Atlantic, by analyzing the geochemical interactions between guano coatings and the underlying rocks. The study also examines the geochemical characteristics of the substrates, assessing the behavior of major, minor, trace, and rare earth elements, and determines the degree of weathering degradation of guano crusts, speleothems, peridotites and carbonate sedimentary rocks affected by environmental factors as rain, wind and halmyrolysis. The distribution of chemical elements in water-soluble, adsorbed, acid-extractable/exchangeable, readily acid and reducible, acid oxidizable, and residual phases were investigated. The principal findings of this method show that elevated Na levels are leached in water-soluble fractions, thereby highlighting the occurrence of rapid and active geochemical cycling, which is influenced by seawater. In contrast, in more acidic environments (pH close 4.8 to 2.0), considerable amounts of macroelements like P, Fe, Mg, Al, and Mn are found in association with remaining phases, indicating a slower and more incremental geochemical cycle of mature guano in the input and output systems of these nutrients in the archipelago. The mineralogy, as indicated by the presence of mafic minerals such as olivine, augite, and Cr-spinel, as well as phosphates including fluorapatite, collinsite, and spheniscidite, also supports this finding. The findings underscore the complex interplay between biological activities and geochemical processes, which influence the elemental dynamics in the phosphate-rich rocks of the SPSPA at depth. This study not only enhances our understanding of phosphatization processes but also offers important insights into the sustainable management of marine resources in environmentally sensitive areas. The research underscores the necessity of considering biological and environmental variables when examining geochemical cycles, particularly in regions exhibiting distinctive geological and biological interactions that challenge the prevailing models, such as those identified in the ASPSP.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105234"},"PeriodicalIF":1.7,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657994","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":"Necrophagous insect damage on Quaternary mammal bones from Brazilian caves: Taphonomic and paleoecological implications","authors":"Laís Alves-Silva ,&nbsp;Ronaldo Araujo Leoni ,&nbsp;Fernando Henrique de Souza Barbosa ,&nbsp;Hermínio Ismael de Araújo-Júnior","doi":"10.1016/j.jsames.2024.105236","DOIUrl":"10.1016/j.jsames.2024.105236","url":null,"abstract":"<div><div>Bioerosion on vertebrate bones provides valuable insights into the post-mortem history of paleocommunities. In this study, we analyzed bioerosion trace fossils on mammalian bones from the Gruta dos Brejões and Toca da Barriguda caves in Bahia, Brazil. Our findings document the occurrence of <em>Cubiculum inornatus</em> and <em>Karethraichnus kulindros</em> in the Pleistocene<em>.</em> Comparisons of these bioerosion traces with trace fossils reported in paleoichnological and neoichnological literature suggest that the traces likely resulted from the pupation of dermestid beetle larvae on carcasses prior to burial. We suggest that dermestid infestation occurred on dry corpses exposed on the surface, which were subsequently transported into the cave environments.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105236"},"PeriodicalIF":1.7,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657993","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":"Characterizing the Namorado Sandstone in southern Brazil through the analysis of a multi-borehole database and utilizing a contemporary workflow","authors":"Abel Carrasquilla ,&nbsp;Apoena Rossi","doi":"10.1016/j.jsames.2024.105219","DOIUrl":"10.1016/j.jsames.2024.105219","url":null,"abstract":"<div><div>The petrophysical characterization of reservoirs requires the identification of sedimentary facies based on the integration of geophysical well logs and rock analyses in the laboratory, which is one of the significant challenges for the petroleum industry. In this work, laboratory analysis results were linked to quality controls of data pre-processing in a new workflow by integrating several techniques. The wells studied were zoned and laterally correlated based on electrofacies characteristic core analysis and petrographic descriptions. This integration resulted in a modeled geologic section for the Namorado Sandstone in the Campos Basin of southeastern Brazil, created based on various data from each well. The borehole NA2 was selected as the key wellbore after creating this section. The logs from this borehole were then analyzed to separate the permo-porous (reservoirs) and non-porous (non-reservoirs) horizons. The zones containing water and hydrocarbons in the permo-porous sections of interest were split along the wells. Subsequently, the identified sectors were interpreted using petrophysical techniques to confirm the preliminary categorization. After combining all quantitative products to quantify the porous layers capable of producing mobile oil, the cut-off factors were introduced. The next step was determining the parameters of the Archie equation, the amount of clay present, and the water saturation from core descriptions, which led to the discovery of deep laminated sandstones. The results strongly correlate with lithology, geological facies, borehole logs, and petrophysical laboratory data. Based on these findings, it is evident that the clay concentration is the primary factor influencing the oil saturation in this reservoir.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105219"},"PeriodicalIF":1.7,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658258","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":"Estimation and assessment of water erosion in the Peixe Angical basin, Brazil","authors":"Dione P. Cardoso ,&nbsp;Wharley P. dos Santos ,&nbsp;Sérgio H.G. Silva ,&nbsp;Marina N. Merlo ,&nbsp;Salvador F. Acuña-Guzman ,&nbsp;Fausto W. Acerbi Júnior ,&nbsp;Marcelo R. Viola ,&nbsp;Marx L.N. Silva ,&nbsp;Nilton Curi ,&nbsp;Junior C. Avanzi","doi":"10.1016/j.jsames.2024.105235","DOIUrl":"10.1016/j.jsames.2024.105235","url":null,"abstract":"<div><div>Water erosion causes the displacement of soil particles from higher to lower elevations, and this process intensifies when land use and vegetation cover change, such as through the conversion of forests into pastures or agricultural fields. Identifying priority areas for soil and water conservation practices is essential for promoting sustainable agriculture. Equally important is identifying the most influential factors driving erosion, as understanding these can guide effective land management strategies. Machine learning techniques, such as Random Forest, are valuable tools for analyzing large datasets and assessing the importance of variables. The primary aim of this study was to estimate soil losses due to land-use changes in the Peixe Angical Reservoir drainage basin using the Revised Universal Soil Loss Equation (RUSLE) within a Geographic Information System (GIS) framework, and to identify priority areas for soil conservation. Additionally, the study aimed to evaluate the contribution and importance of the RUSLE model factors (R, K, LS, and C) to soil loss using the Random Forest regression algorithm. Soil losses were computed for the chronological scenarios (1990, 2000, 2010, and 2017), using rasters with 90 m resolution to calculate the product of the R, K, LS, and C factors, along with the P factor. These soil losses were classified into erosion risk categories, ranging from very low (0–2.5 Mg ha⁻¹ yr⁻¹) to extremely high (greater than 100 Mg ha⁻¹ yr⁻¹). Soil losses in the basin increased over time. The Random Forest algorithm was applied to evaluate the importance of each factor. Rainfall erosivity was found to vary spatially, ranging from 7047.64 MJ mm ha⁻¹ h⁻¹ yr⁻¹ to 11,348.5 MJ mm ha⁻¹ h⁻¹ yr⁻¹, while the LS factor exhibited values ranging from near 0 to over 20. Litholic Neosol (Entisol) was the predominant soil type in the drainage basin. In terms of land use, forests accounted for the largest portion of the basin: 55.60% in 1990, 51.31% in 2000, 48.88% in 2010, and 48.21% in 2017. The C factor, which reflects vegetation cover, was the most significant contributor to soil loss, accounting for 44.8% in 1990, 43.5% in 2000, 44.2% in 2010, and 44.4% in 2017, followed by the K factor (soil erodibility). These assessment techniques can be utilized in guiding conservation planning, thereby supporting sustainable land use practices.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"149 ","pages":"Article 105235"},"PeriodicalIF":1.7,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578985","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":"Deciphering the complex history of the cabo frio high – SE brazilian continental margin","authors":"D.R. Brandão,&nbsp;A.E. Ferraz,&nbsp;R.J. Jahnert,&nbsp;M. Brito,&nbsp;K. Motoki,&nbsp;F. Braga,&nbsp;S.L.M. Mello,&nbsp;C.G. Silva,&nbsp;L.A.P. Gamboa","doi":"10.1016/j.jsames.2024.105214","DOIUrl":"10.1016/j.jsames.2024.105214","url":null,"abstract":"<div><div>Extensive seismic reflection interpretation of the Cabo Frio High allowed better understanding of its proximal and distal structure. Seismic lines helped map the salt base and recognize the primary geological interfaces, unconformities, faults, and volcanic intrusions. The proximal Cabo Frio High is a continental basement uplift extending mainly into the Campos Basin. The Cabo Frio Outer High, which is of volcanic origin, lies between Santos and Campos Basins. This volcanism is concentrated at the crossing of two significant structures: Cruzeiro do Sul Lineament and Rio de Janeiro Fracture Zone. The Cabo Frio High fits an NW-SE fold axis, which is well correlated with distension along NW-SE direction generating a regional E-W sinistral plate movement, mainly related to the ENE-WNW sinistral Rio de Janeiro transfer zones. The accumulated uplift is approximately 4 km, achieved by at least four uplifting pulses. The uplifting starts in the Albian-Santonian, characterized by the elevation of the northeast portion of Cabo Frio High, followed by erosion. The sill and dikes intruded in the Upper Cretaceous, and the uplift of the southwest portion of the Cabo Frio High characterizes the second uplift pulse. Subaerial Eocene volcanos characterize the third uplifting pulse. The uplifting of the Blue Marker horizon (Oligocene) characterizes the last pulse.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105214"},"PeriodicalIF":1.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593486","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":"New Cingulata (Mammalia, Xenarthra) from the late Neogene Palo Pintado Formation (Northwestern Argentina)","authors":"Alfredo E. Zurita ,&nbsp;Claudia I. Galli ,&nbsp;Daniel Barasoain ,&nbsp;Sofía I. Quiñones ,&nbsp;Carlos A. Luna ,&nbsp;Adriana M. Candela ,&nbsp;Enzo M. Landa Ramírez ,&nbsp;Ricardo N. Alonso","doi":"10.1016/j.jsames.2024.105233","DOIUrl":"10.1016/j.jsames.2024.105233","url":null,"abstract":"<div><div>Cingulata (Early Eocene-Recent) is a very well-diversified clade that reached a high diversity during the early Neogene. In southern South America, there is an evident imbalance in our knowledge of the Neogene diversity along the Northwestern region of Argentina (NWA) compared to the Pampean region (PR), despite the importance of NWA to understanding the hypothetical evolutionary scenarios of several clades. The Palo Pintado Formation (<em>ca</em>. 10–5 Ma) is one of the richest units in NWA, involving both the global warming of the Tortonian (<em>ca</em>. 11.6–7.25 Ma) and the global cooling event of the Messinian (<em>ca</em>. 7.25–5.33), coeval with the widespread of the C4 plants. Despite this, Cingulata from this Formation are still poorly known. Interdisciplinary fieldwork at Calchaqui Valley (Angastaco Basin) yielded several new remains, including Chlamyphoridae Euphractinae <em>Proeuphractus limpidus</em>, <em>Chorobates villossisimus</em> and <em>Prozaedyus</em> sp.; Dasypodidae <em>Dasypus</em> sp.; Pampatheriidae <em>Kraglievichia paranensis</em>; and Glyptodontidae <em>Cranithlastus xibiensis</em>. The “armadillos” <em>P. limpidus</em>, <em>Prozaedyus</em> sp., and <em>Dasypus</em> sp. increase the previously known diversity. The record of <em>Dasypus</em> sp. reinforces recent hypotheses extending the biochron of the genus to the Late Miocene in NWA. The recognized taxonomic diversity of glyptodonts, limited to one species, contrasts with that known from other coeval formations placed both in the south (Andalhuala and Corral Quemado formations, Catamarca Province) and the north (Maimará and Tafna formations, Jujuy Province), revealing a complex biogeographic scenario for this clade during this period. The analyzed deposits are interpreted as accumulated within the channel and formed during episodes of large discharges of water and sediment mostly under a warm subtropical climate, tough there is an aridization recorded at <em>ca</em>. 6 Ma, which is probably related to the increase in the taxonomic diversification of Cingulata along the stratigraphic sequence.</div></div>","PeriodicalId":50047,"journal":{"name":"Journal of South American Earth Sciences","volume":"150 ","pages":"Article 105233"},"PeriodicalIF":1.7,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657992","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}