http://sedici.unlp.edu.ar:80/handle/10915/87333 2026-10-28T04:05:37Z 2026-10-28T04:05:37Z Muñoz, Diego F. Arregui, Mariano Germán Halpern, Karen Olivo, Mariana S. De la Puente, G. Susana Moyano Paz, Damián Isla, Manuel Fermín http://sedici.unlp.edu.ar:80/handle/10915/199029 2026-09-22T20:48:16Z 2026-01-01T00:00:00Z

Objeto de conferencia XII Jornadas Nacionales de Ciencias del Mar y XX Coloquio de Oceanografía (Puerto Madryn, 1º al 5 de diciembre de 2025); Libro de resúmenes II Jornadas Nacionales de Ciencias del Mar - XX Coloquio de Oceanografía The Balcarce Formation (southeast Buenos Aires province) has been studied for decades. Historically, this unit was broadly considered a tide-dominated, shallow, open-marine environment, characterised by the presence of several trace fossils as the single palaeontological record. Different studies have suggested that the age of the Balcarce Formation was between the Cambrian and the Silurian.

2026-01-01T00:00:00Z The Balcarce Formation (southeast Buenos Aires province) has been studied for decades. Historically, this unit was broadly considered a tide-dominated, shallow, open-marine environment, characterised by the presence of several trace fossils as the single palaeontological record. Different studies have suggested that the age of the Balcarce Formation was between the Cambrian and the Silurian. Pierattini Martinez, Regina Paparazzo, Flavio E. Bermejo, Paula Lucero, Johana E. Epherra, Lucía Crespi Abril, Augusto Cosentino, Nicolás J. Scivetti, Nicolás Richiano, Sebastián Miguel Poiré, Daniel Gustavo Barbieri, Elena S. http://sedici.unlp.edu.ar:80/handle/10915/198960 2026-09-21T20:29:42Z 2026-01-01T00:00:00Z

Objeto de conferencia XII Jornadas Nacionales de Ciencias del Mar y XX Coloquio de Oceanografía (Puerto Madryn, 1º al 5 de diciembre de 2025); Libro de resúmenes II Jornadas Nacionales de Ciencias del Mar - XX Coloquio de Oceanografía El polvo eólico es transportado a través de la atmósfera desde el continente hacia el océano, conectando el sistema terrestre con el marino. El polvo depositado en el mar genera cambios químicos al aportar nutrientes e influir en la productividad biológica. Los estudios de los efectos directos del polvo en el Mar Argentino son escasos. Este trabajo propone evaluar experimentalmente el impacto de diferentes stocks de polvo patagónico sobre la química del agua de mar.

2026-01-01T00:00:00Z El polvo eólico es transportado a través de la atmósfera desde el continente hacia el océano, conectando el sistema terrestre con el marino. El polvo depositado en el mar genera cambios químicos al aportar nutrientes e influir en la productividad biológica. Los estudios de los efectos directos del polvo en el Mar Argentino son escasos. Este trabajo propone evaluar experimentalmente el impacto de diferentes stocks de polvo patagónico sobre la química del agua de mar. Zandomeni, Priscila S. Moreno, Juan A. Morales Cámera, Matías M. Verdecchia, Sebastián O. Baldo, Edgardo G. Dahlquist, Juan.A. Casquet, César Basei, Miguel A.S. Santos da Cruz, Gilmara Rapela, Carlos Washington http://sedici.unlp.edu.ar:80/handle/10915/196458 2026-07-02T04:27:01Z 2026-01-01T00:00:00Z

Articulo Gondwana Research; vol. 150 The late Ediacaran to early Cambrian Pampean magmatic arc in Argentina represents an excellent example of subduction-related magmatism and continental crust formation. This study presents new geochemical, isotopic, and geochronological data from the Guasayán intrusive complex, which is a significant body within this magmatic arc. The data are integrated with a comprehensive compilation of published data from the arc else­ where. The Pampean arc exhibits a wide range of rocks, from metaluminous I-type diorites to strongly per­ aluminous S-type granites, with the majority displaying hybrid compositions (mostly magnesian, calc-alkalic and slightly peraluminous compositions). Zircon U-Pb geochronology indicates that the Guasayán granitoids were emplaced mainly during a flare-up of arc magmatism between ca. 530 and 535 Ma. However, the presence of zircon antecrysts with ages of ca. 545 Ma in most of the Pampean arc granitoids, suggests that the magmatic system was long-lived, and the early crystallized zircon crystals were recycled into younger magmatic pulses. Geochemical and isotope data (Sr-Nd-Hf) highlight the interaction between mantle-derived magmas and crustal components, with magma mixing identified as the dominant process in the generation of the hybrid granitoids. Local-scale processes such as crustal assimilation, fractional crystallization, and peritectic entrainment also contributed to the geochemical and isotopic diversity. The involvement of the Puncoviscana Series as the crustal component of the mixed magmas is evidenced by zircon inheritance patterns and isotopic signatures. This study underscores the importance of magma mixing in the evolution of the Pampean arc and provides insights into the geodynamic processes driving continental crust formation in subduction-related settings.

2026-01-01T00:00:00Z The late Ediacaran to early Cambrian Pampean magmatic arc in Argentina represents an excellent example of subduction-related magmatism and continental crust formation. This study presents new geochemical, isotopic, and geochronological data from the Guasayán intrusive complex, which is a significant body within this magmatic arc. The data are integrated with a comprehensive compilation of published data from the arc else­ where. The Pampean arc exhibits a wide range of rocks, from metaluminous I-type diorites to strongly per­ aluminous S-type granites, with the majority displaying hybrid compositions (mostly magnesian, calc-alkalic and slightly peraluminous compositions). Zircon U-Pb geochronology indicates that the Guasayán granitoids were emplaced mainly during a flare-up of arc magmatism between ca. 530 and 535 Ma. However, the presence of zircon antecrysts with ages of ca. 545 Ma in most of the Pampean arc granitoids, suggests that the magmatic system was long-lived, and the early crystallized zircon crystals were recycled into younger magmatic pulses. Geochemical and isotope data (Sr-Nd-Hf) highlight the interaction between mantle-derived magmas and crustal components, with magma mixing identified as the dominant process in the generation of the hybrid granitoids. Local-scale processes such as crustal assimilation, fractional crystallization, and peritectic entrainment also contributed to the geochemical and isotopic diversity. The involvement of the Puncoviscana Series as the crustal component of the mixed magmas is evidenced by zircon inheritance patterns and isotopic signatures. This study underscores the importance of magma mixing in the evolution of the Pampean arc and provides insights into the geodynamic processes driving continental crust formation in subduction-related settings. Galone, Luciano D'Amico, Sebastiano Fucks, Enrique Eduardo Colica, Emanuele Carol, Eleonora Silvina Rivero, Luís Panzera, Francesco Rosa, María Laura http://sedici.unlp.edu.ar:80/handle/10915/196185 2026-06-26T11:51:07Z 2026-01-01T00:00:00Z

Articulo Journal of Applied Geophysics; vol. 250 Sedimentary plains host extensive Quaternary sequences whose internal impedance architecture is often poorly constrained, limiting the resolution of subsurface layering and its lateral continuity. We conducted a dense single-station ambient-noise HVSR survey (82 sites) across the La Plata–Berisso–Ensenada area, in the northeastern Pampean Region of Argentina, to characterize both deep and shallow impedance contrasts. The data consistently reveal two frequency modes. The fundamental resonance (f₀ ≈ 0.30–0.40 Hz) exhibits a compact spatial distribution and a smooth basinward increase, indicating a laterally continuous, deep impedance contrast that reflects the large-scale sedimentary thickening toward the Salado Basin. In contrast, the higher-frequency peak (f₁ ≈ 2–12 Hz) displays strong geomorphic and lithogenic controls. Inland, heterogeneous values are consistent with stiffness contrasts produced by pedogenic horizons and loess–paleosol variability within the Pampeano Formation. Across the coastal plain, lower and more organized f₁ values form shore-parallel bands that delineate the Holocene cover overlying Pampeano sediments. A short vertical transect at a quarry constrains the inland f₁-generating contrast to the upper ∼10–15 m, supporting its interpretation as a near-surface mechanical boundary. Together, these patterns show that systematic HVSR mapping can resolve both basin-scale impedance gradients and intra-sedimentary contrasts within thick Quaternary successions. The approach provides a scalable, non-invasive framework for integrating subsurface impedance structure, surface geomorphology, and stratigraphic interpretation in data-limited plain environments.

2026-01-01T00:00:00Z Sedimentary plains host extensive Quaternary sequences whose internal impedance architecture is often poorly constrained, limiting the resolution of subsurface layering and its lateral continuity. We conducted a dense single-station ambient-noise HVSR survey (82 sites) across the La Plata–Berisso–Ensenada area, in the northeastern Pampean Region of Argentina, to characterize both deep and shallow impedance contrasts. The data consistently reveal two frequency modes. The fundamental resonance (f₀ ≈ 0.30–0.40 Hz) exhibits a compact spatial distribution and a smooth basinward increase, indicating a laterally continuous, deep impedance contrast that reflects the large-scale sedimentary thickening toward the Salado Basin. In contrast, the higher-frequency peak (f₁ ≈ 2–12 Hz) displays strong geomorphic and lithogenic controls. Inland, heterogeneous values are consistent with stiffness contrasts produced by pedogenic horizons and loess–paleosol variability within the Pampeano Formation. Across the coastal plain, lower and more organized f₁ values form shore-parallel bands that delineate the Holocene cover overlying Pampeano sediments. A short vertical transect at a quarry constrains the inland f₁-generating contrast to the upper ∼10–15 m, supporting its interpretation as a near-surface mechanical boundary. Together, these patterns show that systematic HVSR mapping can resolve both basin-scale impedance gradients and intra-sedimentary contrasts within thick Quaternary successions. The approach provides a scalable, non-invasive framework for integrating subsurface impedance structure, surface geomorphology, and stratigraphic interpretation in data-limited plain environments. Borges Vaz, Erika Gómez Peral, Lucía Elena Raigemborn, María Sol Messineo, Pablo Gerónimo http://sedici.unlp.edu.ar:80/handle/10915/191722 2026-03-11T20:24:15Z 2019-01-01T00:00:00Z

Objeto de conferencia XX Congreso Nacional de Arqueología Argentina (CNAA) (Córdoba, 15 al 19 de julio de 2019); Libro de resúmenes XX Congreso Nacional de Arqueología Argentina. 50 años de arqueologías La cerámica del Campo de Dunas del Centro Pampeano ha sido escasamente estudiada. Los antecedentes de investigación sobre esta tecnología, en general, consisten en trabajos que se limitan a la mención de su presencia en sitios arqueológicos sin efectuar un estudio detallado al respecto. Sin embargo, en unos pocos casos es posible encontrar información referida a los aspectos macroscópicos y submacroscópicos de los tiestos, mientras que en otros trabajos se cuenta con una contextualización cronológica de la cerámica para dicha área (Ávila 2011; Catella y Saghessi 2007; Oliva y Panizza 2017; Messineo et al. 2018; Piccoli y Gabrielloni 2012; Politis et al. 2012). Debido a ello, el objetivo de este trabajo es contribuir con uno de los primeros estudios sobre los modos de elaboración cerámica de los grupos cazadores-recolectores que habitaron el Campo de Dunas del Centro Pampeano, mediante el análisis petrográfico y la difracción de rayos X (DRX) de las pastas.

2019-01-01T00:00:00Z La cerámica del Campo de Dunas del Centro Pampeano ha sido escasamente estudiada. Los antecedentes de investigación sobre esta tecnología, en general, consisten en trabajos que se limitan a la mención de su presencia en sitios arqueológicos sin efectuar un estudio detallado al respecto. Sin embargo, en unos pocos casos es posible encontrar información referida a los aspectos macroscópicos y submacroscópicos de los tiestos, mientras que en otros trabajos se cuenta con una contextualización cronológica de la cerámica para dicha área (Ávila 2011; Catella y Saghessi 2007; Oliva y Panizza 2017; Messineo et al. 2018; Piccoli y Gabrielloni 2012; Politis et al. 2012). Debido a ello, el objetivo de este trabajo es contribuir con uno de los primeros estudios sobre los modos de elaboración cerámica de los grupos cazadores-recolectores que habitaron el Campo de Dunas del Centro Pampeano, mediante el análisis petrográfico y la difracción de rayos X (DRX) de las pastas. Nunes Ávila, Janaína Chemale Jr.,Farid Weissheimer de Borba, André Cingolani, Carlos Alberto http://sedici.unlp.edu.ar:80/handle/10915/191502 2026-03-06T04:26:21Z 2003-01-01T00:00:00Z

Objeto de conferencia 2o Congresso Brasileiro de P&D em Petróleo & Gás (Río de Janeiro, 15 al 18 de junio de 2003) This study focuses on the stratigraphic and geochronologic analysis of the deposits related to the faulted active margin of the Cacheuta sub-basin, Cuyo Basin (Triassic), in NW-Argentina. This basin was mainly controlled by extensional tectonics along NW-trending structures inherited from Paleozoic sutures. The whole stratigraphic package of this basin is interpreted as a 2nd order depositional sequence. Lowstand deposits comprise coarse-grained alluvial fans (sheetflood and debris-flow deposits). Fluvial and minor lacustrine deposits with expressive volcaniclastic contribution make up the transgressive systems tract. The maximum flooding surface was traced on lacustrine black shales of the Cacheuta Formation (source rock for petroleum accumulations). The highstand system tract comprises fluvial meandering facies and more sparse volcanic contribution. U/Pb SHRIMP dating of a pyroclastic rock interlayered with basal alluvial fans yielded a magmatic age of 243 ± 4.7 Ma positioned in the Early to Middle Triassic.; O presente estudo discorre sobre a análise estratigráfica e a geocronologia dos depósitos relacionados a margem ativa falhada da sub-bacia de Cacheuta, Bacia de Cuyo (Triássico), NW-Argentina. Esta bacia foi condicionada principalmente pela tectônica extensional e controlada por estruturas de orientação NW, relacionadas à zonas de sutura Paleozóicas. O registro estratigráfico completo da Bacia de Cuyo foi considerado com uma seqüência depositional de 2a ordem. Os depósitos de lowstand compreendem fácies de leques aluviais derivados de processos de sheetflood e fluxo de detritos. Depósitos fluviais e, em menor proporção, lacustres com expressiva contribuição vulcanoclástica, caracterizam o trato de sistemas transgressivo. A superfície de máxima inundação foi traçada nos folhelhos pretos lacustres da Formação Cacheuta (rocha geradora de hidrocarbonetos). O trato de sistemas de highstand compreende depósitos relacionados à ação de canais fluviais meandrantes, sendo a contribuição vulcanoclástica pouco expressiva. Datação U/Pb SHRIMP em uma rocha piroclástica que ocorre intercalada aos leques aluviais basais forneceu idade magmática de 243 ± 4.7 Ma, posicionando estes depósitos no Eotriássico-Mesotriássico.

2003-01-01T00:00:00Z This study focuses on the stratigraphic and geochronologic analysis of the deposits related to the faulted active margin of the Cacheuta sub-basin, Cuyo Basin (Triassic), in NW-Argentina. This basin was mainly controlled by extensional tectonics along NW-trending structures inherited from Paleozoic sutures. The whole stratigraphic package of this basin is interpreted as a 2nd order depositional sequence. Lowstand deposits comprise coarse-grained alluvial fans (sheetflood and debris-flow deposits). Fluvial and minor lacustrine deposits with expressive volcaniclastic contribution make up the transgressive systems tract. The maximum flooding surface was traced on lacustrine black shales of the Cacheuta Formation (source rock for petroleum accumulations). The highstand system tract comprises fluvial meandering facies and more sparse volcanic contribution. U/Pb SHRIMP dating of a pyroclastic rock interlayered with basal alluvial fans yielded a magmatic age of 243 ± 4.7 Ma positioned in the Early to Middle Triassic. O presente estudo discorre sobre a análise estratigráfica e a geocronologia dos depósitos relacionados a margem ativa falhada da sub-bacia de Cacheuta, Bacia de Cuyo (Triássico), NW-Argentina. Esta bacia foi condicionada principalmente pela tectônica extensional e controlada por estruturas de orientação NW, relacionadas à zonas de sutura Paleozóicas. O registro estratigráfico completo da Bacia de Cuyo foi considerado com uma seqüência depositional de 2a ordem. Os depósitos de lowstand compreendem fácies de leques aluviais derivados de processos de sheetflood e fluxo de detritos. Depósitos fluviais e, em menor proporção, lacustres com expressiva contribuição vulcanoclástica, caracterizam o trato de sistemas transgressivo. A superfície de máxima inundação foi traçada nos folhelhos pretos lacustres da Formação Cacheuta (rocha geradora de hidrocarbonetos). O trato de sistemas de highstand compreende depósitos relacionados à ação de canais fluviais meandrantes, sendo a contribuição vulcanoclástica pouco expressiva. Datação U/Pb SHRIMP em uma rocha piroclástica que ocorre intercalada aos leques aluviais basais forneceu idade magmática de 243 ± 4.7 Ma, posicionando estes depósitos no Eotriássico-Mesotriássico. Tickyj, H. Cingolani, Carlos Alberto Varela, Ricardo Chemale Jr, F. http://sedici.unlp.edu.ar:80/handle/10915/191499 2026-03-06T04:26:22Z 2001-01-01T00:00:00Z

Objeto de conferencia III South American Symposium on Isotope Geology (Chile, 21 al 24 de octubre de 2001) The San Rafael Block (SRB) lies in west-central Mendoza province, Argentine (35oS-6830'W), and has SSE-NNW structural cenozoic trends in the pre-Andean region. To the North and South it is bounded by the Cuyo and Neuquen oil basins, respectively. To the East the SRB passes into the Pampean plains vanishing under the modern back arc volcanism and sedimentary cover; to the West the boundary is defined by the Frontal Cordillera. The presence of Grenvillian basement rocks (ca. 1100 Ma) in the Sierras Pampeanas Occidentales, and the Cambrian-Ordovician, mainly carbonatic, sedimentary cover of the Precordillera conform a tectonic terrane of 800 km long, which was named as Occidentalia (Dalla Salda et al., 1992), Precordillera Terrane (Astini et al., 1996) or Cuyania (Ramos, 1995). Geotectonic interpretations based on a large amount of geochronological, paleomagnetical, paleobiogeographical and geological evidences stated that both (basement and carbonatic platform) constitute an alochthonous terrane with laurentian affinities, collided on the proto-Andean margin of South America in Upper Ordovician-Silurian (?) times (Ramos, et al., 1998; Astini, 1998; Pankhurst et al., 1998). Paleontological and geological evidences allow interpreting the SRB as a southern extension of the Precordillera (Keller, 1999). On the eastern part of the SRB have been identified a Grenvillian basement and an Ordovician carbonatic sequence at Ponon Trehue (Bordonaro et al., 1996; Cingolani y Varela, 1999; Keller, 1999), and an Ordovician turbiditic deposits at Cerro Bola (Cuerda and Cingolani, 1998). However, the relation with other pre-Carboniferous units of the SRB with Precordillera, e.g. La Horqueta Fm., Rio Seco de los Castanos Fm., El Nihuil doleritic and gabbroic rocks, is controversial due to the scarce geological, paleontological and geochronological data. We present here, as part of a research project on pre- Carboniferous units from SRB, new Rb-Sr geochronological data from La Horqueta Formation (Dessanti, 1956) that contribute to constrain the timing of the main deformation and low grade metamorphism of this unit (au)

2001-01-01T00:00:00Z The San Rafael Block (SRB) lies in west-central Mendoza province, Argentine (35oS-6830'W), and has SSE-NNW structural cenozoic trends in the pre-Andean region. To the North and South it is bounded by the Cuyo and Neuquen oil basins, respectively. To the East the SRB passes into the Pampean plains vanishing under the modern back arc volcanism and sedimentary cover; to the West the boundary is defined by the Frontal Cordillera. The presence of Grenvillian basement rocks (ca. 1100 Ma) in the Sierras Pampeanas Occidentales, and the Cambrian-Ordovician, mainly carbonatic, sedimentary cover of the Precordillera conform a tectonic terrane of 800 km long, which was named as Occidentalia (Dalla Salda et al., 1992), Precordillera Terrane (Astini et al., 1996) or Cuyania (Ramos, 1995). Geotectonic interpretations based on a large amount of geochronological, paleomagnetical, paleobiogeographical and geological evidences stated that both (basement and carbonatic platform) constitute an alochthonous terrane with laurentian affinities, collided on the proto-Andean margin of South America in Upper Ordovician-Silurian (?) times (Ramos, et al., 1998; Astini, 1998; Pankhurst et al., 1998). Paleontological and geological evidences allow interpreting the SRB as a southern extension of the Precordillera (Keller, 1999). On the eastern part of the SRB have been identified a Grenvillian basement and an Ordovician carbonatic sequence at Ponon Trehue (Bordonaro et al., 1996; Cingolani y Varela, 1999; Keller, 1999), and an Ordovician turbiditic deposits at Cerro Bola (Cuerda and Cingolani, 1998). However, the relation with other pre-Carboniferous units of the SRB with Precordillera, e.g. La Horqueta Fm., Rio Seco de los Castanos Fm., El Nihuil doleritic and gabbroic rocks, is controversial due to the scarce geological, paleontological and geochronological data. We present here, as part of a research project on pre- Carboniferous units from SRB, new Rb-Sr geochronological data from La Horqueta Formation (Dessanti, 1956) that contribute to constrain the timing of the main deformation and low grade metamorphism of this unit (au) Vaamonde, Claudio Nievas, Ricardo Fridman, Diego Aragón, Eugenio González, Pablo Diego Cavarozzi, Claudia Ernestina Stevenazzi, José Eduardo Pérez, Sindy Barros, Roberto Miodownik, Cynthia http://sedici.unlp.edu.ar:80/handle/10915/190850 2026-02-24T04:24:37Z 2017-01-01T00:00:00Z

Objeto de conferencia !ron paper and the Abrasuveness of Volcanic ash in Respiratory health. Disaster risk Management Research Project XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) Este proyecto busca estudiar el mecanismo y el alcance real por el cual aparecen, después de una erupción y emisión de cenizas volcánicas recientes, patologías respiratorias en las poblaciones afectadas. Específicamente, nos centraremos en aquella población que habita la zona de Gral. Roca y que presenta síntomas de neumonía. En primer lugar estudiaremos la peligrosidad geológica de las cenizas volcánicas de dos volcanes chilenos como son el Caulle (Puyehue-Cordón Caulle) y el Calbuco. Estudiaremos la composición química, mineralógica, granulométrica, morfológica (abrasividad) de las cenizas emitidas en el año 2011 y 2015 por los aparatos volcánicos que afectaron a las inmediaciones de la localidad de General Roca, Pcia de Río Negro, Argentina. En segundo lugar, estudiaremos el crecimiento de colonias bacterianas en medios de cultivos específicos, con ceniza volcánica, de forma tal de poder analizar la influencia del hierro y de la Lactoferrina en el tamaño de las colonias. Se comparará además, las texturas de las cenizas volcánicas a fin de determinar la abrasividad de las mismas y su potencial efecto negativo en la salud respiratoria. Por último, analizaremos la incidencia de la Neumonía Adquirida en la Comunidad (NAC) en la población de General Roca luego de la erupción del 2015, específicamente en la población etaria mayor de 18 años y en aquella que se considera de alto riesgo como es la mayor de 65 años. Nuestro estudio es un aporte, desde la perspectiva de la geología y la gestión de riesgos de desastres, a la prevención de las sociedades vulnerables.; This project seeks to study the mechanism and the actual extent to which, after a recent eruption and emission of volcanic ash, respiratory pathologies appear in affected populations. Specifically, we will focus on the population that lives in the Gral. Roca area and has symptoms of pneumonia. In the first time, we will study the geological hazards of volcanic ash from two Chilean volcanoes, such as Caulle (Puyehue-Cordón Caulle) and Calbuco. We will study the chemical composition, mineralogical, granulometric, morphological (abrasivity) of the ashes emitted in 2011 and 2015 by the volcanic apparatuses that affected the vicinity of the locality of General Roca, Pcia of Rio Negro, Argentina. Second, we will study the growth of bacterial colonies in specific culture media, with volcanic ash, in order to be able to analyze the influence of iron and Lactoferrin on the size of the colonies. The volcanic ash textures will also be compared in order to determine the abrasiveness of the volcanic ash and its potential negative effect on respiratory health. Finally, we will analyze the incidence of Community Acquired Pneumonia (NAC) in the population of General Roca after the eruption of 2015, specifically in the population aged over 18 years and in that which is considered high risk as is the over 65 years old. Our study is a contribution, from the perspective of geology, and disaster risk management, to the prevention of vulnerable societies.

2017-01-01T00:00:00Z Este proyecto busca estudiar el mecanismo y el alcance real por el cual aparecen, después de una erupción y emisión de cenizas volcánicas recientes, patologías respiratorias en las poblaciones afectadas. Específicamente, nos centraremos en aquella población que habita la zona de Gral. Roca y que presenta síntomas de neumonía. En primer lugar estudiaremos la peligrosidad geológica de las cenizas volcánicas de dos volcanes chilenos como son el Caulle (Puyehue-Cordón Caulle) y el Calbuco. Estudiaremos la composición química, mineralógica, granulométrica, morfológica (abrasividad) de las cenizas emitidas en el año 2011 y 2015 por los aparatos volcánicos que afectaron a las inmediaciones de la localidad de General Roca, Pcia de Río Negro, Argentina. En segundo lugar, estudiaremos el crecimiento de colonias bacterianas en medios de cultivos específicos, con ceniza volcánica, de forma tal de poder analizar la influencia del hierro y de la Lactoferrina en el tamaño de las colonias. Se comparará además, las texturas de las cenizas volcánicas a fin de determinar la abrasividad de las mismas y su potencial efecto negativo en la salud respiratoria. Por último, analizaremos la incidencia de la Neumonía Adquirida en la Comunidad (NAC) en la población de General Roca luego de la erupción del 2015, específicamente en la población etaria mayor de 18 años y en aquella que se considera de alto riesgo como es la mayor de 65 años. Nuestro estudio es un aporte, desde la perspectiva de la geología y la gestión de riesgos de desastres, a la prevención de las sociedades vulnerables. This project seeks to study the mechanism and the actual extent to which, after a recent eruption and emission of volcanic ash, respiratory pathologies appear in affected populations. Specifically, we will focus on the population that lives in the Gral. Roca area and has symptoms of pneumonia. In the first time, we will study the geological hazards of volcanic ash from two Chilean volcanoes, such as Caulle (Puyehue-Cordón Caulle) and Calbuco. We will study the chemical composition, mineralogical, granulometric, morphological (abrasivity) of the ashes emitted in 2011 and 2015 by the volcanic apparatuses that affected the vicinity of the locality of General Roca, Pcia of Rio Negro, Argentina. Second, we will study the growth of bacterial colonies in specific culture media, with volcanic ash, in order to be able to analyze the influence of iron and Lactoferrin on the size of the colonies. The volcanic ash textures will also be compared in order to determine the abrasiveness of the volcanic ash and its potential negative effect on respiratory health. Finally, we will analyze the incidence of Community Acquired Pneumonia (NAC) in the population of General Roca after the eruption of 2015, specifically in the population aged over 18 years and in that which is considered high risk as is the over 65 years old. Our study is a contribution, from the perspective of geology, and disaster risk management, to the prevention of vulnerable societies. Rapela, Carlos Washington Pankhurst, R. J. Casquet, C. Fanning, C. M. Dahlquist, J. A. Galindo, C. Verdecchia, S. Baldo, E.G. Murra, J. A. Alasino, P. H. Ramacciotti, C. http://sedici.unlp.edu.ar:80/handle/10915/190844 2026-02-24T04:24:38Z 2017-01-01T00:00:00Z

Objeto de conferencia Growth of the proto-Andean active margin of Gondwana in the Ordovician. Evidence from U-Pb zircon chronology and Hf-0 isotope composition. XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) New U-Pb ages and Hf and O isotope determinations in zircon have been obtained from a 500 km transect in the Sierras Pampeanas and two different areas ofNE Patagonia that allows us (a) to raise strict isotopic and geochemical constraints on the origin ofthe Famatinian (Ordovician) magmas and (b) to develop a geodynamic scenario for the construction of the SW Gondwana margin. In the Sierras Pampeanas, the Famatinian orogen has been subdivided into four domains: Western (WFD), Central (CFD), Eastern (EFD) and Foreland (FFD). Early Ordovician magmatism dominates the transect from 485 Mato 468 Ma, with major flare-ups at 480 ± 3 Ma and 4 70 ± 2 M. The distribution of ages suggest expansion of the main are towards the west, as rocks of the older pulse has not been reported in the western sector of the CFD and the WFD: large crustal sections are entirely composed by rocks of the younger pulse. Famatinian basic rocks mostly show the same evolved whole-rock Sr and Nd isotopic signature and zircon i:Hf1 values as the intermediate and acid rocks of the same metaluminous sequence. Thus a complete Proterozoic litho - spheric section including the subcontinental mantle has been proposed as the primary magma source. Hybridization of these magmas with high 87Sr/86 initial ratio and high 8180%0 (zircon) melts of Ediacaran and Early Paleozoic metasediments can account for most ofthe Famatinian magmas in the Sierras Pampeanas and Patagonia.

2017-01-01T00:00:00Z New U-Pb ages and Hf and O isotope determinations in zircon have been obtained from a 500 km transect in the Sierras Pampeanas and two different areas ofNE Patagonia that allows us (a) to raise strict isotopic and geochemical constraints on the origin ofthe Famatinian (Ordovician) magmas and (b) to develop a geodynamic scenario for the construction of the SW Gondwana margin. In the Sierras Pampeanas, the Famatinian orogen has been subdivided into four domains: Western (WFD), Central (CFD), Eastern (EFD) and Foreland (FFD). Early Ordovician magmatism dominates the transect from 485 Mato 468 Ma, with major flare-ups at 480 ± 3 Ma and 4 70 ± 2 M. The distribution of ages suggest expansion of the main are towards the west, as rocks of the older pulse has not been reported in the western sector of the CFD and the WFD: large crustal sections are entirely composed by rocks of the younger pulse. Famatinian basic rocks mostly show the same evolved whole-rock Sr and Nd isotopic signature and zircon i:Hf1 values as the intermediate and acid rocks of the same metaluminous sequence. Thus a complete Proterozoic litho - spheric section including the subcontinental mantle has been proposed as the primary magma source. Hybridization of these magmas with high 87Sr/86 initial ratio and high 8180%0 (zircon) melts of Ediacaran and Early Paleozoic metasediments can account for most ofthe Famatinian magmas in the Sierras Pampeanas and Patagonia. Poiré, Daniel Gustavo Iglesias, Ari Varela, Augusto Nicolás Richiano, Sebastián Miguel Ibañez Mejía, Mauricio Strómerg, Caroline A.E. http://sedici.unlp.edu.ar:80/handle/10915/190839 2026-02-24T04:24:39Z 2017-01-01T00:00:00Z

Objeto de conferencia XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) La Formación Piedra Clavada(= Fm. Kachaike) es una unidad litoestratigráfica muy significativa (306 m de espesor) en el registro sedimentario cretácico de la Cuenca Austral, en el sur de la Patagonia, Argentina, debido a que representa un gran sistema deltaico de tipo "margen pasivo", desarrollado durante la etapa de subsidencia termal o sag, previo al inicio del desarrollo de una etapa de cuenca de antepaís. Asimismo, esta unidad alberga una de las más diversas fauna y flora marinas y litorales de la región. Sin embargo, la edad exacta de la Formación Piedra Clavada era imprecisa y estimada por diferentes autores de acuerdo a su contenido fósil, en un rango que se extiende Aptiano superior al Cenomaniano. El objetivo de esta contribución es señalar la edad U-Pb de esta unidad, tomada de zircones de dos niveles de tobas, de la parte superior de la Formación Piedra Clavada. Es importante señalar que la edad obtenida (100-101 Ma) coincide con el evento oceánico anóxico ld (OAEld), que genera en pelitas negras euxínicas en los fondos oceánicos y gran proliferación biológica en áreas litorales y continentales.

2017-01-01T00:00:00Z La Formación Piedra Clavada(= Fm. Kachaike) es una unidad litoestratigráfica muy significativa (306 m de espesor) en el registro sedimentario cretácico de la Cuenca Austral, en el sur de la Patagonia, Argentina, debido a que representa un gran sistema deltaico de tipo "margen pasivo", desarrollado durante la etapa de subsidencia termal o sag, previo al inicio del desarrollo de una etapa de cuenca de antepaís. Asimismo, esta unidad alberga una de las más diversas fauna y flora marinas y litorales de la región. Sin embargo, la edad exacta de la Formación Piedra Clavada era imprecisa y estimada por diferentes autores de acuerdo a su contenido fósil, en un rango que se extiende Aptiano superior al Cenomaniano. El objetivo de esta contribución es señalar la edad U-Pb de esta unidad, tomada de zircones de dos niveles de tobas, de la parte superior de la Formación Piedra Clavada. Es importante señalar que la edad obtenida (100-101 Ma) coincide con el evento oceánico anóxico ld (OAEld), que genera en pelitas negras euxínicas en los fondos oceánicos y gran proliferación biológica en áreas litorales y continentales. Poiré, Daniel Gustavo Iribarne, Martín Allcca Torres, Miguel Castillo Guzmán, Edson J. Pérez, Leandro Martín Callot, Pierre Quevedo, Carlos D. Vergani, Gustavo Dardo http://sedici.unlp.edu.ar:80/handle/10915/190837 2026-02-24T04:24:41Z 2017-01-01T00:00:00Z

Objeto de conferencia Paleogene continental sedimentary facies on the Ene and Pachitea basins, Ucayali and Junín departments, Perú XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) A recent stratigraphic, sedimentological and paleontological survey, in the Apurucayali River, Puerto Ocopa- Río Pangá and Huantashiri creeks, have allowed to recognize and detailed the Paleo gene units of the Ene and Pachitea basins, in the departments of Junín and Ucayali, in the center-eastem of Perú. The aim of this contribution is to make known the results of these studies and to discuss the sedimentary processes and environments that lead up in this region during Paleogene times. The methodology was based on the survey of sedimentological profiles of 1: 100, characterization of sand bodies and pelitic packages, recognition of organic sedimentary structures (traces fossils and rhizoliths ), record and identification of paleontological content, observation of paleoecological and taphonomic aspects, identification of sedimentary processes and interpretation of possible paleoenvironments and depositacional systems. The Paleogene lithostratigraphic units recorded from base to top are the Cachiyacu, Huchpayacu, Yahuarango, Pozo and Chambira formations. On the base of the sedimentary facies and the paleontological record, a continental fluvial-lake deposition system has been recognized, while lightly paleoclimatic changes have been occurring during their sedimentation. Finally, it is important to note that i) the development of the Pozo Formation is identified for the first time in these basins, which was in doubt, and ii) pyroclastic material of Eocene age (40-42 Ma) were found in the lower section of the Chambira Formation, in the three localities.

2017-01-01T00:00:00Z A recent stratigraphic, sedimentological and paleontological survey, in the Apurucayali River, Puerto Ocopa- Río Pangá and Huantashiri creeks, have allowed to recognize and detailed the Paleo gene units of the Ene and Pachitea basins, in the departments of Junín and Ucayali, in the center-eastem of Perú. The aim of this contribution is to make known the results of these studies and to discuss the sedimentary processes and environments that lead up in this region during Paleogene times. The methodology was based on the survey of sedimentological profiles of 1: 100, characterization of sand bodies and pelitic packages, recognition of organic sedimentary structures (traces fossils and rhizoliths ), record and identification of paleontological content, observation of paleoecological and taphonomic aspects, identification of sedimentary processes and interpretation of possible paleoenvironments and depositacional systems. The Paleogene lithostratigraphic units recorded from base to top are the Cachiyacu, Huchpayacu, Yahuarango, Pozo and Chambira formations. On the base of the sedimentary facies and the paleontological record, a continental fluvial-lake deposition system has been recognized, while lightly paleoclimatic changes have been occurring during their sedimentation. Finally, it is important to note that i) the development of the Pozo Formation is identified for the first time in these basins, which was in doubt, and ii) pyroclastic material of Eocene age (40-42 Ma) were found in the lower section of the Chambira Formation, in the three localities. Japas, María Silvia Vizán, Haroldo Prezzi, Claudia Geuna, Silvana Evangelina Franzese, Juan Rafael Renda, Emiliano Oriolo, Sebastián http://sedici.unlp.edu.ar:80/handle/10915/190829 2026-02-24T04:24:42Z

Objeto de conferencia Pangea, self-subduction and Mesozoic extensional basins in the southwestern margin of Gondwana XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) Un modelo geodinámico reciente responsabiliza a la autosubducción de Pangea de los cambios de escenario tectónico en el margen sudoeste de Gondwana entre el Paleozoico tardío y el Mesozoico medio. Entre ca. 230 y 160 Ma, se instaló un régimen extensional en la región, el cual condujo al desarrollo de importantes cuencas extensionales tales como las cuencas Cuyana, Neuquina, de Chubut y Austral. En el marco de este nuevo modelo geodinámico, se analizan en esta contribución los principales rasgos estructurales de las etapas de rift de dichas cuencas, proponiéndose un modelo geodinámico de evolución regional del sistema extensional mesozoico para la región.; Between the Late Paleozoic and the Middle Mesozoic, the self-subduction of Pangea resulted in significant geodynamic and tectonic changes in Gondwana. From ca. 230 to 160 Ma, an extensional regime incepted in the southwestern margin of Gondwana leading to the formation of some extensional depocentres such as the Cuyo, Neuquina, Chubut and Austral basins. Following this geodynamic scenario, the present contribution will analyze the main structural features linked to the rift stage of these basins, proposing a geodynamic evolutionary model.

Un modelo geodinámico reciente responsabiliza a la autosubducción de Pangea de los cambios de escenario tectónico en el margen sudoeste de Gondwana entre el Paleozoico tardío y el Mesozoico medio. Entre ca. 230 y 160 Ma, se instaló un régimen extensional en la región, el cual condujo al desarrollo de importantes cuencas extensionales tales como las cuencas Cuyana, Neuquina, de Chubut y Austral. En el marco de este nuevo modelo geodinámico, se analizan en esta contribución los principales rasgos estructurales de las etapas de rift de dichas cuencas, proponiéndose un modelo geodinámico de evolución regional del sistema extensional mesozoico para la región. Between the Late Paleozoic and the Middle Mesozoic, the self-subduction of Pangea resulted in significant geodynamic and tectonic changes in Gondwana. From ca. 230 to 160 Ma, an extensional regime incepted in the southwestern margin of Gondwana leading to the formation of some extensional depocentres such as the Cuyo, Neuquina, Chubut and Austral basins. Following this geodynamic scenario, the present contribution will analyze the main structural features linked to the rift stage of these basins, proposing a geodynamic evolutionary model. Hervé, Francisco Calderón, Mauricio Fanning, Christopher M. Pankhurst, Robert J. Fuentes, Francisco Quezada, Paulo Rapela, Carlos Washington http://sedici.unlp.edu.ar:80/handle/10915/190826 2026-02-24T04:24:42Z 2017-01-01T00:00:00Z

Objeto de conferencia XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) The Paleozoic growth of the West Gondwana margin is thought to have resulted from successive terrane accre - tions. The Precordillera terrane (or in its more extended form, Cuyania) collided in Ordovician times and the hypo - thetical terrane of Chilenia (which has no known outcrops and whose dimensions are therefore hard to establish) in the Devonian. The Devonian collision of Chilenia is derived from the presence of high grade metamorphic rocks of that age in the Guarguaraz complex in western Argentina (Massone and Calderón, 2008). Chilenia has been considered to be a microcontinent underlain by late Proterozoic basement on the basis detrital zircons of that age, with no obvious other source, in Paleozoic successions of north central Chile (Álvarez et al. 2011). The Huincul lineament of the Neuquén basin has been proposed as the southern limit of Chilenia but this could be extended further since Devonian metamorphic rocks occur south of Bariloche (Cruz Martinez et al. 2011). New information based on SHRIMP U-Pb ages has revealed that following the inferred Devonian collision a Carboniferous and Permian subduction complex formed in the trailing edge of the terrane in Central Chile. North of Chilenia, the Devonian was a period of magmatic quiescence, and very few detrital zircons of that age have been found in the later sedimentary successions (Pankhurst et al. 2016). South of the Neuquén basin, however, Devonian zircons are abundant in the accretionary complex, and some Devonian plutonic rocks are also present (Hervé et al. 2016). The latter form two magmatic belts representing a double subduction environment – an eastern one built over continental crust of the North Patagonian Massif, and a western one formed in an oceanic environment. Thus, to the south of Chilenia, the microcontinent is replaced by a Devonian oceanic arc, here called Chaitenia, which was also accreted to the continental margin of Gondwana. This scenario reflects a transition from Mariana-type subduction on the southwestern Gondwana margin to Andean- type subduction, starting in the Carboniferous, with accretionary complexes built mainly of oceanic material replacing elongated continental terranes.

2017-01-01T00:00:00Z The Paleozoic growth of the West Gondwana margin is thought to have resulted from successive terrane accre - tions. The Precordillera terrane (or in its more extended form, Cuyania) collided in Ordovician times and the hypo - thetical terrane of Chilenia (which has no known outcrops and whose dimensions are therefore hard to establish) in the Devonian. The Devonian collision of Chilenia is derived from the presence of high grade metamorphic rocks of that age in the Guarguaraz complex in western Argentina (Massone and Calderón, 2008). Chilenia has been considered to be a microcontinent underlain by late Proterozoic basement on the basis detrital zircons of that age, with no obvious other source, in Paleozoic successions of north central Chile (Álvarez et al. 2011). The Huincul lineament of the Neuquén basin has been proposed as the southern limit of Chilenia but this could be extended further since Devonian metamorphic rocks occur south of Bariloche (Cruz Martinez et al. 2011). New information based on SHRIMP U-Pb ages has revealed that following the inferred Devonian collision a Carboniferous and Permian subduction complex formed in the trailing edge of the terrane in Central Chile. North of Chilenia, the Devonian was a period of magmatic quiescence, and very few detrital zircons of that age have been found in the later sedimentary successions (Pankhurst et al. 2016). South of the Neuquén basin, however, Devonian zircons are abundant in the accretionary complex, and some Devonian plutonic rocks are also present (Hervé et al. 2016). The latter form two magmatic belts representing a double subduction environment – an eastern one built over continental crust of the North Patagonian Massif, and a western one formed in an oceanic environment. Thus, to the south of Chilenia, the microcontinent is replaced by a Devonian oceanic arc, here called Chaitenia, which was also accreted to the continental margin of Gondwana. This scenario reflects a transition from Mariana-type subduction on the southwestern Gondwana margin to Andean- type subduction, starting in the Carboniferous, with accretionary complexes built mainly of oceanic material replacing elongated continental terranes. Odino Barreto, Andrea Lorena Gómez Peral, Lucía Elena Richiano, Sebastián Miguel Poiré, Daniel Gustavo http://sedici.unlp.edu.ar:80/handle/10915/190706 2026-02-20T04:26:50Z

Objeto de conferencia Compositional analyses of the Calafate Formation (Maastrichtian) in the Cerro Calafate area, Austral Basin, Santa Cruz Province, Argentina: first results XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) Los primeros resultados del análisis composicional de las areniscas marinas de la Formación Calafate (Maastrichtiano) de la Cuenca Austral, en el Cerro Calafate, indican que las mismas están constituidas enteramente por li - toarenitas feldespáticas de tamaño de grano medio, sin embargo pueden ser diferenciadas en dos petrofacies (A y B). Ambas petrofacies presentan diferencias composicionales reconocidas no solo petrográficamente sino también por análisis de difracción de rayos X. Estas petrofacies se corresponden con diferencias reconocidas en los afloramientos, ya que cada una está representada en una sección del perfil limitadas entre sí por una superficie erosiva que coincide conla aparición de depósitos conglomerádicos de hasta medio metro de espesor. Con los resultados obtenidos, se sugiere dividir a la unidad en dos secciones, una sección inferior representada por la petrofacies A con mayor contenido de cuarzo monocristalino y escasas plagioclasas. En esta petrofacies se reconocen procesos deillitización de los cementos argílicos compuestos principalmente por interestratificados de clorita/esmectita e illita/es - mectita. La petrofacies B caracteriza a la sección superior, cuyo cambio composicional se reconoce por la disminución en cuarzo monocristalino y aumento de las plagioclasas (calco-sódicas) sin alteración, que se asocia a un cambio en la procedencia evidenciado por un aumento relativo de la basicidad de las rocas, en esta sección el cemento argílico se compone casi exclusivamente de esmectita glauconítica.; The compositional analysis of marine sandstones of the Calafate Formation( Maastichtian) of the Austral Basin, located in the Cerro Calafate in di cates that they are composed by feldes - pathic litharenites differentiated in two petrofacies A and B. These petrofacies present compositional differences determined by petrography and X-ray diffraction studies. Moreover, the petrofacies correspond to sections in the outcrops, divided by an intraformational erosive surface which coincides with the beginning of conglomerates deposits (up to 50 cm thick). Results here presented allow to divide the unit in a lower section characterized by petrofacies A with scarce to moderate monocrystalline quartz (Qm) and orthose (O), in which processes of illitization of the clay cements produce interestratified clays as chlorite-smectite(C/S) and illite-smectite (1/S).The petrofacies Bis typical ofthe upper section, where the compositional variation is denoted by an important increment in well preserved plagioclases (Ca- Na) anda detriment in Qm, related to a change in the provenance also reflected in the composition of the argillic cementation composed almost exclusively of glauconitic smectite.

Los primeros resultados del análisis composicional de las areniscas marinas de la Formación Calafate (Maastrichtiano) de la Cuenca Austral, en el Cerro Calafate, indican que las mismas están constituidas enteramente por li - toarenitas feldespáticas de tamaño de grano medio, sin embargo pueden ser diferenciadas en dos petrofacies (A y B). Ambas petrofacies presentan diferencias composicionales reconocidas no solo petrográficamente sino también por análisis de difracción de rayos X. Estas petrofacies se corresponden con diferencias reconocidas en los afloramientos, ya que cada una está representada en una sección del perfil limitadas entre sí por una superficie erosiva que coincide conla aparición de depósitos conglomerádicos de hasta medio metro de espesor. Con los resultados obtenidos, se sugiere dividir a la unidad en dos secciones, una sección inferior representada por la petrofacies A con mayor contenido de cuarzo monocristalino y escasas plagioclasas. En esta petrofacies se reconocen procesos deillitización de los cementos argílicos compuestos principalmente por interestratificados de clorita/esmectita e illita/es - mectita. La petrofacies B caracteriza a la sección superior, cuyo cambio composicional se reconoce por la disminución en cuarzo monocristalino y aumento de las plagioclasas (calco-sódicas) sin alteración, que se asocia a un cambio en la procedencia evidenciado por un aumento relativo de la basicidad de las rocas, en esta sección el cemento argílico se compone casi exclusivamente de esmectita glauconítica. The compositional analysis of marine sandstones of the Calafate Formation( Maastichtian) of the Austral Basin, located in the Cerro Calafate in di cates that they are composed by feldes - pathic litharenites differentiated in two petrofacies A and B. These petrofacies present compositional differences determined by petrography and X-ray diffraction studies. Moreover, the petrofacies correspond to sections in the outcrops, divided by an intraformational erosive surface which coincides with the beginning of conglomerates deposits (up to 50 cm thick). Results here presented allow to divide the unit in a lower section characterized by petrofacies A with scarce to moderate monocrystalline quartz (Qm) and orthose (O), in which processes of illitization of the clay cements produce interestratified clays as chlorite-smectite(C/S) and illite-smectite (1/S).The petrofacies Bis typical ofthe upper section, where the compositional variation is denoted by an important increment in well preserved plagioclases (Ca- Na) anda detriment in Qm, related to a change in the provenance also reflected in the composition of the argillic cementation composed almost exclusively of glauconitic smectite. García, Micaela Romina López, Manuel Bucher, Joaquín Funes, Daniela Soledad D'Elia, Leandro Bilmes, Andrés Franzese, Juan Rafael http://sedici.unlp.edu.ar:80/handle/10915/190701 2026-02-20T04:26:51Z

Objeto de conferencia Progressive deformation in the igneous-metamorphic basement of the southern Neuquén Basin, Piedra del Águila, Argentina XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) El basamento ígneo-metamórfico de la región austral de la Cuenca Neuquina está constituido por paragneises migmáticos intruidos por abundantes cuerpos plutónicos deformados. En esta región se realizó un análisis estructural combinando técnicas tradicionales de campo con técnicas de modelado 3D de afloramiento por fotogrametría (i.e.Structure from motion-SfM-). La zona de estudio fue dividida en los sectores Oriental, Central y Occidental en función de la estructura presente. El análisis de los tres sectores permitió el reconocimiento de una esquistosidad (S1) deformada por pliegues apretados o cerrados (F2) con plano axial de orientación N-S y eje de pliegue levemente buzante al S, sectores en donde la esquistosidad (S 1) se encuentra prácticamente obliterada producto de pro - fusas inyecciones graníticas y por último el desarrollo de una faja de cizalla con cinemática transcurrente dextral. Trabajos previos definen en la región tres o más eventos de deformación superpuestos que no se corresponden con lo observado en la zona de estudio. Los resultados de este trabajo indican que en la región de Piedra del Águila las estructuras del basamento se desarrollan por deformación progresiva en un único evento.; Migmatic paragneisses intruded by deformed plutonic rocks constitute the igneous-metamorphic basement of the southern Neuquén Basin. A structural analysis was made by means of traditional field techniques and 3D modeling of outcrop by photogrammetry (i.e. Structure from motion-SfM-). According to structural considerations, the study area was subdivided into three zones, i.e. Eastern, central and western areas. A schistosity (S 1) deformed by tight or closed folds (F2) with axial planes N-S and moderately south-dipping fold axes was recognized in the eastern area. Zones where profuse granitic injections practically obliterated the schistosity (S 1) were observed in the central zone. Finally a shear belt with trancurrent dextral kinematics was recognized in the western zone. A superposition of three or more deformation events were defined by previous works that do not correspond to the observations made in the study area. In conclusion, the basement structures of the Piedra del Águila region were developed by progressive deformation in a single event.

El basamento ígneo-metamórfico de la región austral de la Cuenca Neuquina está constituido por paragneises migmáticos intruidos por abundantes cuerpos plutónicos deformados. En esta región se realizó un análisis estructural combinando técnicas tradicionales de campo con técnicas de modelado 3D de afloramiento por fotogrametría (i.e.Structure from motion-SfM-). La zona de estudio fue dividida en los sectores Oriental, Central y Occidental en función de la estructura presente. El análisis de los tres sectores permitió el reconocimiento de una esquistosidad (S1) deformada por pliegues apretados o cerrados (F2) con plano axial de orientación N-S y eje de pliegue levemente buzante al S, sectores en donde la esquistosidad (S 1) se encuentra prácticamente obliterada producto de pro - fusas inyecciones graníticas y por último el desarrollo de una faja de cizalla con cinemática transcurrente dextral. Trabajos previos definen en la región tres o más eventos de deformación superpuestos que no se corresponden con lo observado en la zona de estudio. Los resultados de este trabajo indican que en la región de Piedra del Águila las estructuras del basamento se desarrollan por deformación progresiva en un único evento. Migmatic paragneisses intruded by deformed plutonic rocks constitute the igneous-metamorphic basement of the southern Neuquén Basin. A structural analysis was made by means of traditional field techniques and 3D modeling of outcrop by photogrammetry (i.e. Structure from motion-SfM-). According to structural considerations, the study area was subdivided into three zones, i.e. Eastern, central and western areas. A schistosity (S 1) deformed by tight or closed folds (F2) with axial planes N-S and moderately south-dipping fold axes was recognized in the eastern area. Zones where profuse granitic injections practically obliterated the schistosity (S 1) were observed in the central zone. Finally a shear belt with trancurrent dextral kinematics was recognized in the western zone. A superposition of three or more deformation events were defined by previous works that do not correspond to the observations made in the study area. In conclusion, the basement structures of the Piedra del Águila region were developed by progressive deformation in a single event. Serra Varela, Samanta González, Pablo Diego Giacosa, Raúl E. Heredia, Nemesio Sato, Ana María http://sedici.unlp.edu.ar:80/handle/10915/190695 2026-02-20T04:26:54Z

Objeto de conferencia Physical conditions of the high temperature - low pressure metamorphism far the Lower Paleozoic basement rocks of San Martín de los Andes area, Neuquén XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) El basamento metamórfico de la zona de San Martín de los Andes incluye esquistos, gneises y migmatitas que se encuentran intruidos por granitoides devónicos que cortan las estructuras de dichas rocas. Se trata de un basamento relacionado con un ciclo pre-Gondwanico del que se desconoce su extensión regional en los Andes Nordpatagónicos. Análisis petrográficos y de pseudosecciones PT nos permitieron determinar parámetros fisicos para caracterizar las condiciones del metamorfismo. Las migmatitas se encontrarían en una serie de baja presión y alta temperatura (LP-HT), en la transición entre las facies anfibolita y granulita. Considerando las características del metamorfismo y su edad (pre-Devónico), no se han encontrado rocas equivalentes a las de San Martín de los Andes en áreas cordilleranas aledañas con afloramientos de basamento pre-andino.; Metamorphic rocks from San Martín de los Andes area comprise schists, gneisses and migmatites. These rocks are intruded by Devonian granitoids that cut the metamorphic intemal structure of these rocks. These rocks belong to a pre-Gondwanan cycle and its regional extension in the Nordpatagonian Andes is unknown. Petrographic analysis and PT pseudosections allowed us to determine physical parameters in order to characterize the metamorphic conditions. Migmatic rocks would be part of a low pressure - high temperature series (LP-HT) in the transition between amphibolite and granulite facies. Considering its metamorphic characteristics and age (pre-Devonian), no equivalent rocks have yet been found in nearby areas with outcrops of pre-Andine basement.

El basamento metamórfico de la zona de San Martín de los Andes incluye esquistos, gneises y migmatitas que se encuentran intruidos por granitoides devónicos que cortan las estructuras de dichas rocas. Se trata de un basamento relacionado con un ciclo pre-Gondwanico del que se desconoce su extensión regional en los Andes Nordpatagónicos. Análisis petrográficos y de pseudosecciones PT nos permitieron determinar parámetros fisicos para caracterizar las condiciones del metamorfismo. Las migmatitas se encontrarían en una serie de baja presión y alta temperatura (LP-HT), en la transición entre las facies anfibolita y granulita. Considerando las características del metamorfismo y su edad (pre-Devónico), no se han encontrado rocas equivalentes a las de San Martín de los Andes en áreas cordilleranas aledañas con afloramientos de basamento pre-andino. Metamorphic rocks from San Martín de los Andes area comprise schists, gneisses and migmatites. These rocks are intruded by Devonian granitoids that cut the metamorphic intemal structure of these rocks. These rocks belong to a pre-Gondwanan cycle and its regional extension in the Nordpatagonian Andes is unknown. Petrographic analysis and PT pseudosections allowed us to determine physical parameters in order to characterize the metamorphic conditions. Migmatic rocks would be part of a low pressure - high temperature series (LP-HT) in the transition between amphibolite and granulite facies. Considering its metamorphic characteristics and age (pre-Devonian), no equivalent rocks have yet been found in nearby areas with outcrops of pre-Andine basement. Heredia, Nemesio Farias, Pedro García-Sansegundo, Joaquín Gallastegui, Gloria Giacosa, Raúl Hongn, Fernando Tubía, José María Alonso, Juan L. Busquets, Pere Charrier, Reynaldo Clariana, María Pilar Colombo, Ferrán Cuesta, Andrés Gallastegui, Jorge Giambiagi, Laura González Menéndez, Luis Limarino, Carlos Oscar Martín González, Fidel Pedreira, David Quintana, Luis Rodríguez-Fernández, Luis R. Rubio-Ordóñez, Alvaro Seggiaro, Raúl Serra Varela, Samanta Spalletti, Luis Antonio Cardó, Raúl Ramos, Víctor A. http://sedici.unlp.edu.ar:80/handle/10915/190665 2026-02-20T04:26:54Z 2017-01-01T00:00:00Z

Objeto de conferencia XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) During the late Neoproterozoic and Paleozoic, the Argentinean-Chilean Andes and, since the late Paleozoic, the Antarctic Peninsula formed part of the southwestern margin of Gondwana. During this long period of the geological time, a set of continetal fragments of variable size and allochtonie was successively accreted to that margin. This process, coupled with the development of several subductive systems, resulted in six Paleozoic orogenies, which have different temporal and spatial extensions: Pampean (Neoproterozoic-early Cambrian), Famatinian (Middle Ordovician- Silurian), Ocloyic (Middle Ordovician-Devonian), Chanic (Middle Devonian-early Carboniferous), Gondwanan (Middle Devonian-middle Permian) and Tabarin (late Permian-Triassic). All these orogenies had a collisional character, with the exception of the Tabarin and a part of the Gondwanan orogenies that are subduction-related.

2017-01-01T00:00:00Z During the late Neoproterozoic and Paleozoic, the Argentinean-Chilean Andes and, since the late Paleozoic, the Antarctic Peninsula formed part of the southwestern margin of Gondwana. During this long period of the geological time, a set of continetal fragments of variable size and allochtonie was successively accreted to that margin. This process, coupled with the development of several subductive systems, resulted in six Paleozoic orogenies, which have different temporal and spatial extensions: Pampean (Neoproterozoic-early Cambrian), Famatinian (Middle Ordovician- Silurian), Ocloyic (Middle Ordovician-Devonian), Chanic (Middle Devonian-early Carboniferous), Gondwanan (Middle Devonian-middle Permian) and Tabarin (late Permian-Triassic). All these orogenies had a collisional character, with the exception of the Tabarin and a part of the Gondwanan orogenies that are subduction-related. Greco, Gerson Alan González, Santiago Nicolás Sato, Ana María González, Pablo Diego Basei, Miguel A. S. Llambías, Eduardo Jorge Varela, Ricardo Serra Varela, Samanta http://sedici.unlp.edu.ar:80/handle/10915/190664 2026-02-20T04:26:56Z 2017-01-01T00:00:00Z

Objeto de conferencia XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) The Nahuel Niyeu Formation is a low-grade metamorphic unit consisting of alternating beds of metasedimentary rocks, derived from siliciclastic protoliths, with minor intercalation of metaigneous rocks. lt is part of the early Paleozoic basement of the eastern North Patagonian Massif. In this contribution, we present new U-Pb detrital zircon ages from three metagreywackes of the Aguada Cecilio area. New maximum depositional ages, together with previous geochronological data, allow us to constrain the depositional age of the siliciclastic protoliths of the Nahuel Niyeu Formation in the Aguada Cecilio area between 516.8-516.2 Ma and 513.6 Ma.

2017-01-01T00:00:00Z The Nahuel Niyeu Formation is a low-grade metamorphic unit consisting of alternating beds of metasedimentary rocks, derived from siliciclastic protoliths, with minor intercalation of metaigneous rocks. lt is part of the early Paleozoic basement of the eastern North Patagonian Massif. In this contribution, we present new U-Pb detrital zircon ages from three metagreywackes of the Aguada Cecilio area. New maximum depositional ages, together with previous geochronological data, allow us to constrain the depositional age of the siliciclastic protoliths of the Nahuel Niyeu Formation in the Aguada Cecilio area between 516.8-516.2 Ma and 513.6 Ma. González, Pablo D. Sato, Ana María Naipauer, Maximiliano Llambías, Eduardo Jorge Basei, Miguel A.S. Chemale Jr, Farid http://sedici.unlp.edu.ar:80/handle/10915/190662 2026-02-20T04:26:58Z 2017-01-01T00:00:00Z

Objeto de conferencia U-Pb Ediacaran-Cambrian ages in protoliths of the Nogolí Metamorphic Complex, San Luis: tectonic implications XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) Se ha establecido la cristalización magmática y la procedencia de protolitos volcano-sedimentarios del Neoproterozoico a Paleozoico temprano del Complejo Metamórfico de Nogolí (Sierras Pampeanas Orientales de San Luis) usando análisis U-Pb ICPMS-LA de zircones magmáticos y detríticos en dos muestras. El patrón de edades de los circones de un paragneis muestra que derivan principalmente de fuentes Brasiliano-Panafricano (Neoproterozoico) y en menor proporción del Mesoproterozoico. La edad de cristalización magmática de una komatiita metamorfizada es 532 ± 11 Ma, mientras que su recristalización metamórfica está entre 507-496 Ma. Esta última acotación temporal se atribuye a la orogénesis del ciclo Pampeano. Desde el punto de vista geotectónico regional, hacia el oeste de las Sierras de Córdoba, la Sierra de San Luis estuvo involucrada en forma diacrónica en el eje orogénico pampeano principal. El metamorfismo y la deformación del Cámbrico Medio-Tardío afectaron tanto a las Sierras de Córdoba como a la de San Luis y se asociaron con la colisión de terrenos.; The Neoproterozic to Early Paleozoic magmatic crystallization and the provenance of the volcano-sedimentary protoliths of the Nogolí Metamorphic Complex (Eastern Sierras Pampeanas of San Luis) have been established using U-Pb LA-ICPMS age determination of magmatic and detrital zircons in two samples. Detrital zircon age pattern from a paragneiss shows that its sedimentary protoliths derived mainly from Brasiliano-Panafricano (Neoproterozoic) sources, with minor input from Mesoproterozoic rocks. The magmatic crystallization age of a metamorphosed komatiite is 532 ± 11 Ma whereas its metamorphic recrystallization is between 507-496 Ma. This last time constraint is ascribed as the orogenic effect of the Pampean cycle. From a regional geotectonic point of view, to the west of Sierras de Córdoba, the Sierra de San Luis was diachronously involved in the main Pampean orogenic axis. The Mid-to-Late Cambrian metamorphism and deformation affected both the Sierras de Córdoba and San Luis, and were associated with terrane collision.

2017-01-01T00:00:00Z Se ha establecido la cristalización magmática y la procedencia de protolitos volcano-sedimentarios del Neoproterozoico a Paleozoico temprano del Complejo Metamórfico de Nogolí (Sierras Pampeanas Orientales de San Luis) usando análisis U-Pb ICPMS-LA de zircones magmáticos y detríticos en dos muestras. El patrón de edades de los circones de un paragneis muestra que derivan principalmente de fuentes Brasiliano-Panafricano (Neoproterozoico) y en menor proporción del Mesoproterozoico. La edad de cristalización magmática de una komatiita metamorfizada es 532 ± 11 Ma, mientras que su recristalización metamórfica está entre 507-496 Ma. Esta última acotación temporal se atribuye a la orogénesis del ciclo Pampeano. Desde el punto de vista geotectónico regional, hacia el oeste de las Sierras de Córdoba, la Sierra de San Luis estuvo involucrada en forma diacrónica en el eje orogénico pampeano principal. El metamorfismo y la deformación del Cámbrico Medio-Tardío afectaron tanto a las Sierras de Córdoba como a la de San Luis y se asociaron con la colisión de terrenos. The Neoproterozic to Early Paleozoic magmatic crystallization and the provenance of the volcano-sedimentary protoliths of the Nogolí Metamorphic Complex (Eastern Sierras Pampeanas of San Luis) have been established using U-Pb LA-ICPMS age determination of magmatic and detrital zircons in two samples. Detrital zircon age pattern from a paragneiss shows that its sedimentary protoliths derived mainly from Brasiliano-Panafricano (Neoproterozoic) sources, with minor input from Mesoproterozoic rocks. The magmatic crystallization age of a metamorphosed komatiite is 532 ± 11 Ma whereas its metamorphic recrystallization is between 507-496 Ma. This last time constraint is ascribed as the orogenic effect of the Pampean cycle. From a regional geotectonic point of view, to the west of Sierras de Córdoba, the Sierra de San Luis was diachronously involved in the main Pampean orogenic axis. The Mid-to-Late Cambrian metamorphism and deformation affected both the Sierras de Córdoba and San Luis, and were associated with terrane collision. Galindo, Carmen Casquet, Cesar Baldo, Edgardo G. A. Pankhurst, Robert Rapela, Carlos Washington Dahlquist, Juan A. Fanning, Mark http://sedici.unlp.edu.ar:80/handle/10915/190658 2026-02-20T04:26:59Z 2017-01-01T00:00:00Z

Objeto de conferencia XX Congreso Geológico Argentino (San Miguel de Tucumán, 7 al 11 de agosto de 2017) U-Pb SHRIMP geochronology and geochemistry of a Mesoproterozoic adakite from the Bloque San Rafael, Mendoza, Argentina: Geotectonic context. In the Ponón Trehue area, within the Mesoproterozoic of San Rafael block, an Adakite orthogneis with a Na2O / K2O = 5.3 ratio, an Eu positive anomaly (Eu/Eu * = 1.83), low Content in REE (~REE = 34.9 ppm) anda marked fractionation ([La/ Yb] N = 16.1) was recognized. It also shows low content in the HREE anda SrN ratio= 87.8. Isotopically it corresponds to a juvenile magmatic rock, ( 87Sr / 86Sr1,2aa = 0,7031 and i::Nd = +4.44) with a model age Nd TDM = 1260 Ma anda crystallization age of 1208.8 ± 8.8 Ma (2°7Pb/2°6Pb SHRIMP age in zircon). This magmatism would represent a period of subduction and accretion of oceanic terrane temporarily correlated with the beginning ofthe Shawinigan orogenesis (1220 - 1200 Ma), ofthe Grenville orogenic cycle and culminating with the formation ofthe Rodinia supercontinent.

2017-01-01T00:00:00Z U-Pb SHRIMP geochronology and geochemistry of a Mesoproterozoic adakite from the Bloque San Rafael, Mendoza, Argentina: Geotectonic context. In the Ponón Trehue area, within the Mesoproterozoic of San Rafael block, an Adakite orthogneis with a Na2O / K2O = 5.3 ratio, an Eu positive anomaly (Eu/Eu * = 1.83), low Content in REE (~REE = 34.9 ppm) anda marked fractionation ([La/ Yb] N = 16.1) was recognized. It also shows low content in the HREE anda SrN ratio= 87.8. Isotopically it corresponds to a juvenile magmatic rock, ( 87Sr / 86Sr1,2aa = 0,7031 and i::Nd = +4.44) with a model age Nd TDM = 1260 Ma anda crystallization age of 1208.8 ± 8.8 Ma (2°7Pb/2°6Pb SHRIMP age in zircon). This magmatism would represent a period of subduction and accretion of oceanic terrane temporarily correlated with the beginning ofthe Shawinigan orogenesis (1220 - 1200 Ma), ofthe Grenville orogenic cycle and culminating with the formation ofthe Rodinia supercontinent.