Ameghiniana最新文献

{"title":"Gondwanan Perspectives: Fossil Wood Anatomy","authors":"Daniela P. Ruiz, M. Brea","doi":"10.5710/1851-8044-60.1.1","DOIUrl":"https://doi.org/10.5710/1851-8044-60.1.1","url":null,"abstract":"","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47595506","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":"African Legume Affinities with the Flora from the Lower la Plata Basin (Upper Cenozoic), South America","authors":"E. Moya, R.S. Ramos, M.J. Franco, M. Brea","doi":"10.5710/amgh.25.08.2022.3521","DOIUrl":"https://doi.org/10.5710/amgh.25.08.2022.3521","url":null,"abstract":"Este artículo presenta un análisis de las afinidades de las leguminosas del Cenozoico superior, halladas en la cuenca baja del Plata (América del Sur), con géneros africanos actuales, y sus implicancias paleoecológicas y paleofitogeográficas. Maderas permineralizadas, asignadas a Entrerrioxylon victoriensis de la Formación Paraná (Mioceno Superior), Gossweilerodendroxylon palmariensis y Paraoxystigma concordiensis de la Formación El Palmar (Pleistoceno Superior) y (Cylicodiscuxylon paragabunensis) de la Formación Arroyo Feliciano (Pleistoceno Superior), presentan afinidades con taxones actuales de Detarioideae y Caesalpinioideae (clado mimosoide). Actualmente, los taxones asignados a Detarioideae se distribuyen principalmente en las regiones tropicales de África, América Central y América del Sur y el género monotípico Cylicodiscus está restringido a África occidental desde Sierra Leona hasta Gabón. En la actualidad, Cylicodiscus, Gossweilerodendron y Oxystigma no están distribuidos en América del Sur, lo que implica que en el pasado tuvieron una mayor distribución y que se extinguieron en esta región en algún momento durante el Pleistoceno–Holoceno, presumiblemente relacionado con los cambios climáticos que ocurrieron durante este intervalo de tiempo. El registro fósil de la cuenca baja del Plata con taxones relacionados a Detarioideae y Cylicodiscus respalda una distribución fitogeográfica más amplia durante el Cenozoico y una vinculación antigua con los bosques tropicales de África occidental.","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135892435","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":"Conifer Fossil Woods from the Late Jurassic–Early Cretaceous (Solari/Botucatú Formation) of the Paraje Tres Cerros (Corrientes Province), Northeast Argentina","authors":"L. Martinez, Roberto R. Pujana, Mateo D. Monferran, Rodrigo Cajade, Alejandra Hernando, V. Zaracho, O. F. Gallego","doi":"10.5710/AMGH.09.01.2023.3543","DOIUrl":"https://doi.org/10.5710/AMGH.09.01.2023.3543","url":null,"abstract":"Abstract. An assemblage of 22 fossil woods was collected from sandstones of the Solari/Botucatú Formation, Late Jurassic–Early Cretaceous, at Paraje Tres Cerros, Corrientes Province, Argentina. The preservation of most fossils is poor. However, twelve samples have radial pitting and a few cross-fields preserved. These characters allow the assignment of fossil woods to the Araucariaceae. All the fossils seem to be of the same taxonomic unit with the following main characteristics: growth ring boundaries distinct (poorly marked), intertracheary araucarian radial pitting, uni- to biseriate bordered pits, wide tracheids, araucarioid cross-field pitting, uniseriate rays, and absence of axial parenchyma and resin canals. The fossils were assigned to cf. Agathoxylon Hartig. The size of the fossil woods and the growth ring curvatures indicate that the samples were part of big trees. The width of the growth rings also indicates significant annual growth. The taxonomic assignment suggests that monospecific forests of Araucariaceae developed in the area. This is the record of the first Mesozoic fossil remains from the Corrientes Province. Resumen. Una asociación compuesta por 22 leños fósiles fueron recolectados en niveles de areniscas pertenecientes a la Formación Solari/Botucatú (Jurásico Tardío–Cretácico Temprano), Paraje Tres Cerros (Corrientes, Argentina). El grado de preservación es pobre en la mayoría de los especímenes. No obstante, doce ejemplares presentan punteaduras en las paredes radiales de las traqueidas y algunos campos de cruzamiento preservados. Estos caracteres permitieron incluirlos dentro de las Araucariaceae. Todos los ejemplares parecen pertenecer a la misma unidad taxonómica presentando las siguientes características principales: anillos de crecimientos poco marcados, punteaduras radiales 1- a 2-seriadas y del tipo araucarioide, traqueidas anchas, campos de cruzamiento araucarioides, radios uniseriados y ausencia de parénquima axial y canales resiníferos. Los especímenes descriptos fueron asignados a cf. Agathoxylon. El tamaño de los leños fósiles y la curvatura de los anillos de crecimiento indican que dichos especímenes se corresponden con árboles de gran tamaño. Además, el ancho de los anillos de crecimiento revela un crecimiento anual significativo. Los caracteres anatómicos presentes en los leños sugieren que en el área se desarrolló un bosque monoespecífico de Araucariaceae. Estos registros son los primeros restos fósiles de edad mesozoica de la provincia de corrientes.","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48747495","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":"Exploring the First Appearance of the Main Derived Conifer Families of Gondwana: Evidence Provided by the Triassic Woods from Argentina","authors":"J. Bodnar, Valentina Cuesta, I. Escapa, Giovanni N. Nunes","doi":"10.5710/AMGH.16.11.2022.3520","DOIUrl":"https://doi.org/10.5710/AMGH.16.11.2022.3520","url":null,"abstract":"Abstract. The relevance of improving the knowledge on Triassic conifers resides in that the modern clades originated during the Late Triassic–Early Jurassic. More than 30 conifer-like fossil woods are known from the Triassic strata of Argentina. Whereas some have not been linked to any family, others have been related to the “Protopinaceae”, Taxaceae, Podocarpaceae, Araucariaceae, Cupressaceae, or Hirmeriellaceae (=Cheirolepidiaceae). The diversity of woods with anatomy close to derived conifers contrasts with the scarce Triassic record of leaves and micro and megasporangiate cones, which could be explained by a combination of taphonomic and evolutionary causes. In order to provide information to resolve this controversy, the anatomy and systematic affinities of Triassic permineralized conifer-like trunks and woods described to date for Argentina were reassessed. As a result of this review, it emerged that the woods previously assigned to Podocarpaceae and Taxaceae do not have enough preserved characters to support such assignment, or they have characters that are homoplasic in the context of Mesozoic gymnosperms and therefore their affinity is ambiguous. On the contrary, the reevaluation of the woods related to the Araucariaceae, Cupressaceae and Hirmeriellaceae (=Cheirolepidiaceae) allows us to support their affinity with these families. Resumen. La importancia en avanzar en el conocimiento de las coníferas triásicas radica en que durante el lapso Triásico Tardío–Jurásico Temprano se produce el origen de los clados modernos. Para el Triásico argentino se conocen más de 30 leños fósiles comparables a las coníferas. Mientras que algunos no se han vinculado con alguna familia, otros han sido relacionados con las “Protopinaceae”, Taxaceae, Podocarpaceae, Araucariaceae, Cupressaceae o Hirmeriellaceae (=Cheirolepidiaceae). La diversidad de leños con morfología afín a las coníferas derivadas contrasta con el escaso registro triásico de hojas y conos micro y megasporangiados, lo que podría deberse a una combinación de causas tafonómicas y evolutivas. Con el objetivo de aportar información que ayude a resolver esta controversia, se revisó la anatomía y la afinidad sistemática de los leños permineralizados de edad triásica descriptos hasta la actualidad para la Argentina. Como resultado de esta revisión, se determinó que los leños previamente asignados a Podocarpaceae y Taxaceae no poseen suficientes caracteres preservados para sostener tal asignación, o presentan caracteres que resultan homoplásicos en el contexto de las gimnospermas mesozoicas y por lo tanto su afinidad es ambigua. Por el contrario, la reevaluación de los leños relacionados a las Araucariaceae, Cupressaceae y Hirmeriellaceae (=Cheirolepidiaceae) permite sostener su afinidad con dichas familias.","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49376140","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":"Redescription of Solanumxylon paranensis, Late Miocene of Paraná Formation (Entre Ríos, Argentina): A Reliable Fossil Wood of Solanaceae","authors":"M. J. Franco, M. Brea","doi":"10.5710/AMGH.13.10.2022.3518","DOIUrl":"https://doi.org/10.5710/AMGH.13.10.2022.3518","url":null,"abstract":"Abstract. The diagnostic anatomical features of Solanumxylon paranensis were restudied using light and scanning electron microscopy. The holotype was collected from Paraná Formation (Late Miocene) in Toma Vieja fossil locality (Entre Ríos, Argentina). The taxonomic position and affinity of the Solanumxylon are discussed, and its diagnosis is extended. The following features suggest affinities with the Solanaceae: diffuse porosity, vessels solitary, and less commonly in radial multiples and in clusters, simple perforation plates, alternate intervessel pits, vessel-ray pits similar to intervessel pits and/or apparently simple, pits rounded in outline, rays 1 to 4 cells wide, all ray cells procumbent or body ray cells procumbent with one row of upright and/or square marginal cells, fibers with simple to minutely bordered pits, septate fibers present, scanty paratracheal parenchyma. This paper provides more details about the systematic assignment of Solanumxylon paranensis within the Solanaceae and its affinity with Solanum. This fossil can be used in phylogenetic studies of the family/genus, increasing our knowledge of Solanum history and diversity. Resumen. Los caracteres diagnósticos de Solanumxylon paranensis fueron reestudiados utilizando microscopio óptico y electrónico. El holotipo de este leño fósil fue encontrado en la Formación Paraná (Mioceno Tardío), en la localidad fosilífera de Toma Vieja (Entre Ríos, Argentina). Se discute la posición taxonómica y la afinidad de Solanumxylon, y se enmienda su diagnosis. La presencia combinada de los siguientes caracteres sugiere afinidades con las Solanaceae: porosidad difusa, vasos solitarios, raramente múltiples radiales y en racimos; placas de perforación simples; punteaduras intervasculares alternas; punteaduras radio-vasculares similares a las punteaduras de los vasos y/o aparentemente simples (redondeadas); radios de 1 a 4 células de ancho, todas las células de los radios procumbentes o procumbentes en el cuerpo con una fila de células marginales verticales y/o cuadradas; fibras con punteaduras simples a aparentemente areoladas, fibras septadas presentes; parénquima axial paratraqueal escaso. Este trabajo proporciona detalles más confiables sobre la asignación sistemática de Solanumxylon paranensis dentro de las Solanaceae y su afinidad con Solanum. Este fósil podría ser utilizado en nuevos estudios filogenéticos, incrementando nuestro conocimiento sobre la historia y diversidad de Solanum.","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41493466","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 Records of Moraceae from the Upper Miocene of Northeastern Argentina","authors":"C. M. Martínez Martínez","doi":"10.5710/AMGH.04.12.2022.3519","DOIUrl":"https://doi.org/10.5710/AMGH.04.12.2022.3519","url":null,"abstract":"Abstract. New records of permineralized fossil woods recovered from the fluvial sediments of Ituzaingó Formation (upper Miocene) in the fossiliferous locality of Toma Vieja (Entre Ríos, Argentina) are described in this work. An eco-anatomical study of the secondary xylem was performed and the fossil woods were assigned to Moraceae. A new genus and species is proposed, Helicostyloxylon paranensis, and a new record of Soroceaxylon entrerriensis Franco is described. Many anatomical features in these fossil woods are related to warm and humid conditions. Also, the Vulnerability and Mesomorphy indices were calculated, both evidencing mesomorphic values, and the Nearest Living Relatives (NLRs) method was used to reveal the riparian or “gallery” forest floristic affinity of these fossil woods. Resumen. En este trabajo se describen nuevos registros de maderas fósiles permineralizadas recuperadas de los sedimentos fluviales de la Formación Ituzaingó (Mioceno superior) en la localidad fosilífera de Toma Vieja (Entre Ríos, Argentina). Se realizó un estudio ecoanatómico del xilema secundario y se asignaron las maderas fósiles a Moraceae. Se propone un nuevo género y especie, Helicostyloxylon paranensis y se describe un nuevo registro de Soroceaxylon entrerriensis Franco. Muchas características anatómicas de estas maderas fósiles están relacionadas con condiciones cálidas y húmedas. Además, se calcularon los índices de Vulnerabilidad y Mesomorfía, ambos mostrando valores mesomórficos, y se utilizó el método del Pariente Actual más Cercano (PAC) para revelar la afinidad florística del bosque ribereño o “en galería” de estas maderas fósiles.","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42393386","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":"Conifer Fossil Woods from the Mid-Cretaceous (Albian) Kachaike Formation, Santa Cruz Province, Argentina","authors":"C. Greppi, Roberto R. Pujana, Daniela P. Ruiz, Cosme F. Rombola, I. Aramendía","doi":"10.5710/amgh.30.11.2022.3523","DOIUrl":"https://doi.org/10.5710/amgh.30.11.2022.3523","url":null,"abstract":"Abstract. We describe 21 silicified woods from the Kachaike Formation (Albian, mid-Cretaceous), collected in the Tucu Tucu Ranch, west-central Santa Cruz Province, Argentinean Patagonia. The specimens are composed entirely of secondary xylem, and their preservation varies among them. Anatomical studies indicate that they are conifers related to the families Araucariaceae and Hirmeriellaceae (=Cheirolepidiaceae) and are placed into two fossil species: Agathoxylon antarcticum and Brachyoxylon patagonicum. All the specimens studied show marked growth rings, indicating annual seasonality. Decay patterns similar to those produced by modern xylophagous fungi are also recognized. The presence of Araucariaceae and Hirmeriellaceae fossil woods allows a better understanding of the paleoflora of the Kachaike Formation, based previously only on palynological and fossil leaf studies. In addition, it provides additional information regarding conifers' dominance of the tree canopy during the Cretaceous of Patagonia. Resumen. Se describen 21 maderas silicificadas de la Formación Kachaike (Albiano, Cretácico medio), recolectadas en la estancia Tucu Tucu, centro-oeste de la provincia de Santa Cruz, Patagonia Argentina. Los especímenes están compuestos enteramente por xilema secundario y el grado de preservación varía entre cada uno de los ejemplares. Los estudios anatómicos indican que son coníferas afines a las familias Araucariaceae e Hirmeriellaceae (=Cheirolepidiaceae), y son asignadas a dos especies fósiles: Agathoxylon antarcticum y Brachyoxylon patagonicum. Todos los ejemplares estudiados presentan anillos de crecimiento marcados, indicando estacionalidad anual. Se reconocen también patrones de pudrición similares a los producidos por hongos xilófagos modernos. La presencia de leños fósiles de Araucariaceae e Hirmeriellaceae permite un mejor entendimiento de la paleoflora de la Formación Kachaike, basada previamente únicamente en estudios palinológicos y de hojas fósiles. Asimismo, brinda información adicional en cuanto a la dominancia del estrato arbóreo por parte de las coníferas durante el Cretácico de Patagonia","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46934735","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":"Late Paleocene to Middle Eocene Calcareous Nannofossil Assemblages from Península Mitre, Southeastern Austral Basin, Argentina","authors":"Erika L. Bedoya Agudelo, J. P. Pérez Panera, A. Concheyro, E. Olivero, Cecilia Gutiérrez, P. T. Torres Carbonell","doi":"10.5710/AMGH.07.02.2023.3530","DOIUrl":"https://doi.org/10.5710/AMGH.07.02.2023.3530","url":null,"abstract":"Abstract. On the Fueguian Atlantic coast and in the southern Andean fold and thrust belt, the Paleogene is partially represented by numerous turbiditic deposits. Between Río Bueno and Cabo Leticia in Península Mitre, the Paleocene–Eocene is represented by the Río Claro Group (Cabo Leticia, La Barca, Punta Noguera, and Cerro Ruperto formations) and the Río Bueno Formation; which together constitute a ∼1050-m-thick succession. Calcareous nannofossil assemblages recovered from 95 samples were analyzed to determine their relative ages. The Cabo Leticia Formation was barren in nannofossils. The upper LB2 Member of La Barca Formation contained Rhomboaster cuspis and Fasciculithus richardii, frequent in the Paleocene/Eocene boundary (subzones NP9a/NP9b). Nannofossils recovered from Punta Noguera Formation indicate an early Eocene age (biozones NP9b–NP10), with Fasciculithus tympaniformis, Rhomboaster cuspis, and abundant Toweius spp. The Cerro Ruperto Formation provided one productive sample, with specimens of Reticulofenestra spp. and Toweius spp., which indicates an early Eocene age for the formation (biozones NP12–NP13). The Río Bueno Formation yields calcareous nannofossil assemblages characterized by Chiasmolithus eograndis, Chiasmolithus expansus, Toweius spp., and Reticulofenestra spp., which indicate a late early Eocene to middle Eocene age (biozones NP14–NP15). Although the calcareous nannofossil record is discontinuous due to preservational biases in the Río Claro Group, our data allow a better age constraint for the investigated formations and to correlate these units with other surface and subsurface units in the Austral Basin. Resumen. En la costa atlántica fueguina y en la faja plegada y corrida de los Andes Fueguinos, el Paleógeno está representado parcialmente por numerosos sistemas turbidíticos. Entre el Río Bueno y el Cabo Leticia en Península Mitre, el Paleoceno–Eoceno está integrado por la Formación Río Bueno y el Grupo Río Claro (formaciones Cabo Leticia, La Barca, Punta Noguera y Cerro Ruperto) que alcanzan ∼1050 m de espesor. En este trabajo se analizan los ensambles de nanofósiles calcáreos de 95 muestras a fin de precisar sus edades relativas. La Formación Cabo Leticia resultó estéril en nanofósiles. El miembro superior de la Formación La Barca, LB2, contiene ejemplares de Rhomboaster cuspis y Fasciculithus richardii, frecuentes en el límite Paleoceno/Eoceno (subzonas NP9a–NP9b). Los nanofósiles recuperados en la Formación Punta Noguera indican una edad Eoceno temprano (biozonas NP9b–NP10), con Fasciculithus tympaniformis, Rhomboaster cuspis y abundantes Toweius spp. La Formación Cerro Ruperto proporcionó una muestra fértil, con ejemplares de Reticulofenestra spp. y Toweius spp., asignables al Eoceno temprano (biozonas NP12–NP13). La Formación Río Bueno, proveyó ensambles de nanofósiles caracterizados por Chiasmolithus eograndis, Chiasmolithus expansus Toweius spp. y Reticulofenestra spp., asignables al Eoceno temprano tardío - ","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2023-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48751336","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 DATA ON THE OSTEOLOGY AND DEVELOPMENT OF AVITABATRACHUS ULIANA (ANURA, XENOANURA), A PIPIMORPH FROM THE CANDELEROS FORMATION, MID CRETACEOUS OF NORTHWESTERN PATAGONIA, ARGENTINA","authors":"Ana M. Baez, Guillermo F. Turazzini","doi":"10.5710/amgh.08.09.2023.3567","DOIUrl":"https://doi.org/10.5710/amgh.08.09.2023.3567","url":null,"abstract":"","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135361409","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 Record of the Lueckisporites/Weylandites Biozone (Permian) in the Paganzo Basin, Argentina: Stratigraphic Significance","authors":"S. N. Césari, C. Limarino, Patricia L. Ciccioli, S. Marenssi, Luis C. Ferreira","doi":"10.5710/AMGH.08.11.2022.3531","DOIUrl":"https://doi.org/10.5710/AMGH.08.11.2022.3531","url":null,"abstract":"Abstract. We present the first palynological assemblages collected from the fine-grained variegated beds that overlie the De La Cuesta Formation at Puerta de Las Angosturas, Sierra de Narváez, Catamarca Province, Argentina. Five samples from two different stratigraphic levels provided spores, non-taeniate, taeniate, and sulcate pollen grains referred to the Lueckisporites/Weylandites (LW) Biozone. The palynofloras are equivalent to those previously reported for the Los Jumes area and, therefore, the variegated sequences that overlie the De La Cuesta Formation at both flanks of the Sierra de Narváez are entirely equivalent, not only lithologically but also in fossiliferous content and age. These assemblages are analogous to those isotopically dated at 278.84±0.22 Ma (Kungurian) in the Valle Hermoso area (La Rioja Province), which constitute a key stratigraphic horizon to link the initial phases of the Permian volcanic arc and the sedimentation in the retroarc basins. The recognition of diagnostic taxa of the LW Biozone confirms earlier correlations with the Striatites Biozone of the Chacoparaná Basin and the Lv Biozone from Brazil. The different ages recently reported for the succession analyzed here in Sierra de Narváez and La Veteada Formation, suggest that these units should not be correlated. Moreover, while the strata overlying the De La Cuesta Formation records the Permian post-orogenic sedimentation in the Paganzo Basin, the La Veteada Formation accounts for the transition to the rifting conditions that characterized the triassic basins of northwestern Argentina. Resumen. Presentamos las primeras asociaciones palinológicas colectadas de los estratos abigarrados de grano fino que sobreyacen a la Formación De La Cuesta en Puerta de Las Angosturas, Sierra de Narváez, provincia de Catamarca, Argentina. Cinco muestras de dos niveles estratigráficos diferentes proporcionaron esporas y granos de polen no teniado, teniado y sulcado, referidos a la Biozona Lueckisporites/Weylandites (LW). Las palinofloras son equivalentes a las previamente reportadas para el área de Los Jumes y, por tanto, las secuencias abigarradas que sobreyacen a la Formación De La Cuesta en ambos flancos de la Sierra de Narváez son totalmente equivalentes, no sólo litológicamente sino también en contenido fosilífero y edad. Estas asociaciones son análogas a las datadas isotópicamente en 278,84±0,22 Ma (Kunguriano) descritas en el área de Valle Hermoso (provincia de La Rioja) las cuales constituyen un horizonte estratigráfico clave para vincular las fases iniciales del arco volcánico pérmico y la sedimentación en las cuencas de retroarco. El reconocimiento de taxones diagnósticos de la Biozona LW confirma correlaciones previas con las biozonas Striatites de la Cuenca Chacoparaná y Lv de Brasil. Las diferentes edades reportadas recientemente para la sucesión aquí analizada en Sierra de Narváez y la Formación La Veteada sugieren que estas unidades no deberían ser correlacionadas. A","PeriodicalId":50819,"journal":{"name":"Ameghiniana","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2022-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43745907","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}