17 results on '"de Porras, María Eugenia"'
Search Results
2. Holocene environmental and climate evolution of central west Patagonia as reconstructed from lacustrine sediments of Meseta Chile Chico (46.5° S, Chile).
- Author
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Franco, Carolina, Maldonado, Antonio, Ohlendorf, Christian, Gebhardt, A. Catalina, de Porras, María Eugenia, Nuevo-Delaunay, Amalia, Méndez, César, and Zolitschka, Bernd
- Subjects
HOLOCENE Epoch ,PRECIPITATION variability ,WESTERLIES ,SEDIMENTS ,ICE caps ,GLACIAL landforms ,GLACIERS - Abstract
Holocene environmental changes in Patagonia were mostly shaped by fluctuating ice cover recession. Consequently, environmental reconstructions are largely based on discontinuous moraine chronologies from valley deposits. Here, we present a 3 m long continuous sediment record recovered from Laguna Meseta (LME), a lake located on Meseta Chile Chico. Its altitude and location relative to the North Patagonian Icefield provide a unique opportunity to reconstruct the glacial history and related environmental dynamics. Our radiocarbon chronology constrains sedimentation to the last ∼10000 years and provides a minimum age for postglacial ice-free lacustrine conditions, due to a westward retreat of the ice cap. Lacustrine productivity reached its maximum at the start of the lake phase and decreased afterwards. Between 5500 and 4600 cal yr BP, a major shift towards allochthonous sediment accumulation occurred, caused by an abrupt increase in clastic deposition from basaltic lithologies of the Meseta Chile Chico. This episode correlates with the precipitation-driven Mid-Holocene glacier advance of Patagonian glaciers and suggests that conditions were colder and/or wetter on Meseta Chile Chico at that time. After 4600 cal yr BP, these conditions continued to supply LME with clastic sediments until a stepped decrease around 900 cal yr BP. Thereupon, lacustrine productivity distinctly increased and stabilized around 300 cal yr BP. Our findings indicate that changes in sedimentation on Meseta Chile Chico were mainly controlled by regional variability in the precipitation. Furthermore, strong correlation between our records and available proxies for oscillations of the Southern Hemisphere Westerly Winds suggest a pronounced climatic control by this prominent wind system for central west Patagonia during the last 10 000 years. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. A multiproxy approach to reconstruct the Late Holocene environmental dynamics of the semiarid Andes of central Chile (29°S)
- Author
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Martel-Cea, Alejandra, primary, Maldonado, Antonio, additional, de Porras, María Eugenia, additional, Muñoz, Praxedes, additional, Maidana, Nora I., additional, Massaferro, Julieta, additional, and Schittek, Karsten, additional
- Published
- 2023
- Full Text
- View/download PDF
4. Holocene environmental and climate evolution of Central West Patagonia as reconstructed from lacustrine sediments of Meseta Chile Chico (46.5º S, Chile).
- Author
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Franco, Carolina, Maldonado, Antonio, Ohlendorf, Christian, Gebhardt, A. Catalina, de Porras, María Eugenia, Nuevo-Delaunay, Amalia, Méndez, César, and Zolitschka, Bernd
- Abstract
Holocene environmental changes in Patagonia were mostly shaped by unsteady ice-cover recession. Consequently, environmental reconstructions are largely based on discontinuous moraine chronologies from valley deposits. Here, we present a 3 m-long continuous sediment record recovered from Laguna Meseta (LME), a lake located on Meseta Chile Chico. Its altitude and location relative to the North Patagonian Icefield provide a unique opportunity to reconstruct the glacial history and the related environmental dynamics. Our radiocarbon chronology constrains sedimentation to the last ~10,000 years and provides a minimum age for postglacial ice-free lacustrine conditions due to a westward retreat of the ice cap. Lacustrine productivity reached its maximum at the start of sedimentation and decreased afterwards. Between 5,500 and 4,600 cal yr BP, a major shift towards allochthonous sediment accumulation occurred, caused by an abrupt increase in clastic deposition from basaltic lithologies of the Meseta Chile Chico. This episode correlates with the precipitation-driven mid-Holocene glacier advance of Patagonian glaciers and suggests that conditions were colder/wetter on the Meseta Chile Chico at that time. After 4,600 cal yr BP these conditions continued to supply LME with clastic sediments until a stepped decrease around 900 cal yr BP. Thereupon, lacustrine productivity distinctly increased and stabilized around 300 cal yr BP. Our findings indicate that environmental conditions on Meseta Chile Chico were mainly controlled by precipitation variability during regional oscillations of the Southern Hemisphere Westerly Winds over the last 10 ka. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Holocene Environmental Dynamics of the Lago Cochrane/Pueyrredón Valley, Central West Patagonia (47°S)
- Author
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Maldonado, Antonio, primary, de Porras, María Eugenia, additional, Martel-Cea, Alejandra, additional, Reyes, Omar, additional, Nuevo-Delaunay, Amalia, additional, and Méndez, César, additional
- Published
- 2022
- Full Text
- View/download PDF
6. Vegetation changes and human occupation in the Patagonian steppe, Argentina, during the late Holocene
- Author
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De Porras, Maria Eugenia, Mancini, Maria Virginia, and Prieto, Aldo Raul
- Published
- 2009
7. Did Modern Precipitation Drivers Influence Centennial Trends in the Highlands of the Atacama Desert During the Most Recent Millennium?
- Author
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Jara, Ignacio A., primary, Maldonado, Antonio, additional, and de Porras, María Eugenia, additional
- Published
- 2021
- Full Text
- View/download PDF
8. Did Modern Precipitation Drivers Influence Centennial Trends in the Highlands of the Atacama Desert During the Most Recent Millennium?
- Author
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Jara, Ignacio A., Maldonado, Antonio, and de Porras, María Eugenia
- Subjects
FOSSIL pollen ,SOUTHERN oscillation ,POLLEN ,PALYNOLOGY ,PRECIPITATION variability ,UPLANDS - Abstract
Although present‐day precipitation variability in the southern Altiplano and adjacent Andean margins (15–25°S) is well understood, past drivers and mechanisms remain little‐explored. We analyzed the pollen assemblages of 31 fossil rodent middens to reconstruct precipitation change during the most recent millennium in the highlands of the Atacama Desert (22°S), on the western foothills of the Altiplano. Variations in low and high elevation pollen types reveal reduced (increased) precipitation between 930 and 550 BP (510 and 440 BP) (BP = before present; taken as Common Era 1950). Variable pollen assemblages prevailed from 390 to 90 BP, followed by a drying trend that persists until present times. Similarities with proxy records from the Altiplano, the tropical Andes and the equatorial Pacific suggest that centennial‐scale wet/dry phases in the Atacama highlands were associated with changes in the strength of the South American monsoon system, most likely influenced by changes akin to modern El Niño Southern Oscillation variability. Plain Language Summary: Fossilized rodent middens are able to preserve plant remains for millennia, representing glimpses of ancient vegetation and climates. Pollen recovered from 31 fossil middens in the Atacama Desert in northern Chile allowed us to reconstruct vegetation and rainfall changes over the most recent millennium. Upslope shifts of low elevation pollen types in middens dated between 930 and 550 years before the present (BP; taken as Common Era 1950) indicates dryer conditions, while downslope shifts of high elevation types suggest wetter climates between 510 and 440 BP. We interpret these dry/wet phases as resulting from changes in regional precipitation associated with the strength of the South American summer monsoon system. A comparison of our midden record with precipitation reconstructions from the Altiplano, the tropical Andes and the equatorial Pacific suggests a pattern of variability similar to that imposed by El Niño/La Niña today. Our reconstruction further suggests that the drivers controlling present‐day precipitation variability may have also influenced decade‐to‐century‐long trends over the last 1,000 years, with the implication that future long‐term changes in El Niño Southern Oscillation behavior will more likely impact precipitation regimes in Atacama Desert and Altiplano. Key Points: Pollen analysis of fossil rodent middens from the Atacama Desert allows reconstructing precipitation trends over the last 1,100 yearsShifts in key pollen types suggest relatively dry conditions during the first half of the last millenniumA tropical driving mechanism is suggested by similarities with records from the Altiplano, the tropical Andes and the equatorial Pacific [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
9. Holocene tephrochronology of the lower Río Cisnes valley, southern Chile
- Author
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Weller, Derek J., de Porras, María Eugenia, Maldonado, Antonio, Méndez, César, and Stern, Charles R.
- Subjects
Tephra ,Tefra ,Tefrocronología ,Tephrochronology ,Chile ,Volcanismo andino ,Andean volcanism - Abstract
Sediment cores from lakes and bogs in the Río Cisnes valley contain tephra from explosive eruptions of volcanoes in the southern part of the Andean Southern Volcanic Zone (SSVZ). These tephra, which thicken and coarsen to the west, are attributed to eruptions from Melimoyu, Mentolat, Hudson, and potentially either Macá, Cay or one of the many minor eruptive centers (MEC) located both along the Liquiñe-Ofqui Fault Zone (LOFZ) and surrounding the major volcanoes. Correlation of the tephra between two new cores in the lower Río Cisnes valley, and amongst other cores previously described from the region, and source volcano identification for the tephra, has been done using lithostratigraphic data (tephra layer thickness and grain size), petrography (tephra glass color, vesicle morphology, and type and abundance of phenocryst phases), and by comparison of bulk tephra trace-element characteristics with previously published whole-rock and bulk tephra chemical analysis. Four tephras in these cores are attributed to eruptions of Mentolat, four to eruptions from Melimoyu, one possibly to Hudson, and six cannot be assigned to a specific source volcano. Some of these tephra correspond to pyroclastic tephra fall deposits previously observed in outcrop, including the MEL2 eruption of Melimoyu and the MEN1 eruption of Mentolat. However, others have not been previously observed and represent the products of newly identified small to medium sized eruptions from volcanoes of the SSVZ. These results provide new information concerning the frequency and magnitude of explosive eruption of SSVZ volcanoes and contribute to the evaluation of volcanic hazards in the region. RESUMEN Los testigos de sedimentos de lagos y pantanos obtenidos en el valle del río Cisnes contienen niveles de tefra originados por erupciones explosivas de volcanes localizados en la parte sur de la Zona Volcánica de los Andes del Sur (SZVS). Estos depósitos de tefra, que aumentan de espesor y tamaño del grano hacia el oeste, son atribuidos a erupciones de los volcanes Melimoyu, Mentolat, Hudson y potencialmente a los volcanes Macá, Cay o alguno de los numerosos centros eruptivos menores (CEM) localizados a lo largo de la Zona de Falla Liquiñe-Ofqui (ZFLO) y que rodean a los volcanes principales. La correlación de los niveles de tefra identificados en dos nuevos testigos, obtenidos en el curso inferior del valle del río Cisnes, con aquellos presentes en testigos descritos con anterioridad en la región y la identificación de los volcanes fuente de las tefras, se realizó con la ayuda de datos litoestratigráficos, (espesor de la capa de tefra y tamaño del grano), petrografía (color de los fragmentos de vidrio, morfología de las vesículas y tipo y abundancia de fenocristales) y por comparación de sus patrones de elementos trazas con análisis químicos de roca total y tefra total publicados con anterioridad. Cuatro niveles de tefras identificados en estos nuevos testigos se atribuyen a erupciones del volcán Mentolat, otros cuatro se asignan al volcán Melimoyu y uno, posiblemente, fue originado por el volcán Hudson. Otros seis no pueden ser asignados a un volcán específico. Algunas de estas tefras corresponden a depósitos de tefras observados previamente en afloramientos, asignados a las erupciones MEL 2 del volcán Melimoyu y MEN 1 del volcán Mentolat. Sin embargo, otros niveles de tefra no han sido reconocidos previamente y representan los productos de erupciones de tamaño pequeño a mediano de los volcanes de la SZVS recientemente identificadas en este trabajo. Estos resultados proporcionan nueva información sobre la frecuencia y magnitud de las erupciones explosivas de los volcanes de la SZVS y contribuyen a la evaluación de los peligros volcánicos en la región.
- Published
- 2017
10. Holocene tephrochronology of the lower Río Cisnes valley, southern Chile
- Author
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Weller,Derek J., de Porras,María Eugenia, Maldonado,Antonio, Méndez,César, and Stern,Charles R.
- Subjects
Tephra ,Tephrochronology ,Chile ,Andean volcanism - Abstract
Sediment cores from lakes and bogs in the Río Cisnes valley contain tephra from explosive eruptions of volcanoes in the southern part of the Andean Southern Volcanic Zone (SSVZ). These tephra, which thicken and coarsen to the west, are attributed to eruptions from Melimoyu, Mentolat, Hudson, and potentially either Macá, Cay or one of the many minor eruptive centers (MEC) located both along the Liquiñe-Ofqui Fault Zone (LOFZ) and surrounding the major volcanoes. Correlation of the tephra between two new cores in the lower Río Cisnes valley, and amongst other cores previously described from the region, and source volcano identification for the tephra, has been done using lithostratigraphic data (tephra layer thickness and grain size), petrography (tephra glass color, vesicle morphology, and type and abundance of phenocryst phases), and by comparison of bulk tephra trace-element characteristics with previously published whole-rock and bulk tephra chemical analysis. Four tephras in these cores are attributed to eruptions of Mentolat, four to eruptions from Melimoyu, one possibly to Hudson, and six cannot be assigned to a specific source volcano. Some of these tephra correspond to pyroclastic tephra fall deposits previously observed in outcrop, including the MEL2 eruption of Melimoyu and the MEN1 eruption of Mentolat. However, others have not been previously observed and represent the products of newly identified small to medium sized eruptions from volcanoes of the SSVZ. These results provide new information concerning the frequency and magnitude of explosive eruption of SSVZ volcanoes and contribute to the evaluation of volcanic hazards in the region.
- Published
- 2017
11. Pollen morphology of Cactaceae in Northern Chile
- Author
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MIESEN, FLOREANA, DE PORRAS, MARÍA EUGENIA, and MALDONADO, ANTONIO
- Abstract
Chile is habitat to over 140 species of cactus of which 45% are endemic and most of them grow in the arid northernmost part of the country between 18°-32°S. As the Cactaceae family plants are quite well adapted to arid environments, their fossil pollen may serve as a tool to reconstruct past environmental dynamics as well as to trace some issues regarding the family evolution or even some autoecological aspects. Aiming to create a reference atlas to be applied to some of these purposes, the pollen morphology of the following 14 different species of the Cactaceae family from Northern Chile was studied under optical microscopy: Cumulopuntia sphaerica, Maihueniopsis camachoi, Tunilla soehrensii, Echinopsis atacamensis, Echinopsis coquimbana, Haageocereus chilensis, Oreocereus hempelianus, Oreocereus leucotrichus, Copiapoa coquimbana, Eriosyce aurata, Eriosyce subgibbosa, Eulychnia breviflora, Browningia candelaris and Corryocactus brevistylus. Pollen grains of species of the subfamily Opuntioideae are spheroidal, apolar and periporate whereas grains of the subfamily Cactoideae are subspheroidal, bipolar and tricolpate and can be taxonomically differentiated between tribes. The results show that it is possible to identify pollen from the Cactaceae family at the genus level but pollen taxonomic resolution may be complicated to identify up to a specific level. A wider reference collection considering more characters than those included in the present study could improve this aspect in the near future. Actualmente crecen en Chile más de 140 especies de cactus, de las cuales el 45% son endémicas y la mayoría de ellas se distribuyen en la zona norte y más árida del país entre 18°-32°S. Como las Cactáceas se encuentran muy bien adaptadas a los ambientes áridos, el polen fósil de esta familia puede ser utilizado como herramienta para reconstruir la dinámica ambiental pasada así como para estudiar aspectos relacionados a su historia evolutiva o bien de su autoecología. Con el objetivo de crear una colección de referencia asociada a los propósitos mencionados anteriormente, se estudió con microscopía óptica la morfología del polen de las siguientes 14 especies de Cactáceas del norte de Chile: Cumulopuntia sphaerica, Maihueniopsis camachoi, Tunilla soehrensii, Echinopsis atacamensis, Echinopsis coquimbana, Haageocereus chilensis, Oreocereus hempelianus, Oreocereus leucotrichus, Copiapoa coquimbana, Eriosyce aurata, Eriosyce subgibbosa, Eulychnia breviflora, Browningia candelaris y Corryocactus brevistylus. Los granos de polen de las especies de la subfamilia Opuntioideae son esferoidales, apolares y periporados. Granos de la subfamilia Cactoideae son subesferoidales, isopolares y tricolpados y se pueden diferenciar taxonómicamente entre tribus. Los resultados indican que es posible diferenciar los granos de polen de las Cactáceas a nivel de género pero que debido a la resolución taxonómica de este análisis, la determinación a nivel de especie sería más complicada. Sin embargo, una colección de polen de referencia de cactáceas más amplia y considerando más caracteres que los incluidos en este trabajo podrían mejorar este problema en el futuro.
- Published
- 2015
12. Holocene tephrochronology of the lower Río Cisnes valley, southern Chile
- Author
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Weller, Derek J., primary, De Porras, María Eugenia, additional, Maldonado, Antonio, additional, Méndez, César, additional, and Stern, Charles R., additional
- Published
- 2017
- Full Text
- View/download PDF
13. Estudio de la relación polen-vegetación actual en el Norte de Chile, en el transecto Pozo Almonte-Salar de Huasco (20º15’S/69º06’O)
- Author
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COLLAO-ALVARADO,KATHY, MALDONADO,ANTONIO, GONZÁLEZ,LETICIA, SANDOVAL,ANA, DE PORRAS,MARÍA EUGENIA, ZAMORA,ANDRÉS, and ARANCIO,GINA
- Abstract
La diversidad vegetal de la zona andina del Norte Grande de Chile ha sido estudiada desde diversos puntos de vista (florísticos, fisonómicos, etnobotánicos, conservacionistas, etc.); sin embargo, hasta ahora no se ha estudiado desde un punto de vista palinológico. Así, este trabajo tiene como objetivo aportar al conocimiento de la vegetación y su señal polínica en los distintos pisos altitudinales del Norte Grande de Chile, aportando además a la identificación de los principales tipos polínicos presentes. Este estudio presenta la relación entre lluvia de polen y vegetación actual en un transecto altitudinal entre Pozo Almonte y el Salar de Huasco, en el norte de Chile, junto con fotografías y descripciones de 12 morfotipos polínicos representativos de la zona. Los resultados de los muestreos de vegetación corroboran las tendencias descritas en trabajos previos identificándose los principales pisos de vegetación descritos anteriormente (piso prepuneño, puneño, altoandino y subnival). De igual manera los resultados de la lluvia de polen muestran una clara relación con los ensambles de vegetación que la produce, siendo posible diferenciar cada uno de los pisos de vegetación a partir de su señal polínica. Así, los resultados pueden ser de gran interés para la interpretación de registros polínicos fósiles o para estudios de carácter ecológico.
- Published
- 2015
14. Estudio de la relación polen-vegetación actual en el Norte de Chile, en el transecto Pozo Almonte-Salar de Huasco (20º15’S/69º06’O)
- Author
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COLLAO-ALVARADO, KATHY, MALDONADO, ANTONIO, GONZÁLEZ, LETICIA, SANDOVAL, ANA, DE PORRAS, MARÍA EUGENIA, ZAMORA, ANDRÉS, and ARANCIO, GINA
- Abstract
La diversidad vegetal de la zona andina del Norte Grande de Chile ha sido estudiada desde diversos puntos de vista (florísticos, fisonómicos, etnobotánicos, conservacionistas, etc.); sin embargo, hasta ahora no se ha estudiado desde un punto de vista palinológico. Así, este trabajo tiene como objetivo aportar al conocimiento de la vegetación y su señal polínica en los distintos pisos altitudinales del Norte Grande de Chile, aportando además a la identificación de los principales tipos polínicos presentes. Este estudio presenta la relación entre lluvia de polen y vegetación actual en un transecto altitudinal entre Pozo Almonte y el Salar de Huasco, en el norte de Chile, junto con fotografías y descripciones de 12 morfotipos polínicos representativos de la zona. Los resultados de los muestreos de vegetación corroboran las tendencias descritas en trabajos previos identificándose los principales pisos de vegetación descritos anteriormente (piso prepuneño, puneño, altoandino y subnival). De igual manera los resultados de la lluvia de polen muestran una clara relación con los ensambles de vegetación que la produce, siendo posible diferenciar cada uno de los pisos de vegetación a partir de su señal polínica. Así, los resultados pueden ser de gran interés para la interpretación de registros polínicos fósiles o para estudios de carácter ecológico. The plant diversity found in the Andean region of the Norte Grande area in Chile has been studied from different points of view (floral, physiognomy, ethnobotanical, conservationists, etc.). Nevertheless, there has not been any research done from a palynological point of view until now. Thus, this investigation’s objective is to contribute knowledge about the vegetation and its pollen signal in the different altitudinal tiers of the Norte Grande area in Chile, and to help identify the main pollen types present here. This research shows the relationship between pollen rain and current vegetation in the Pozo Almonte and Salar de Huasco altitudinal transect in the north of Chile, together with pictures and descriptions of 12 pollen kind typically found in this area. The results of the vegetation’s collection confirm the tendency of previous studies revealing the principal altitudinal tiers of vegetation ("piso prepuneño, puneño, altoandino y subnival"). Likewise, the results of the pollen rain show an important relationship with the vegetation that produce it, making it possible to discriminate the different altitudinal tiers from its pollen signal. Thus the results can be of great interest for fossil pollen records understanding or for ecological studies.
- Published
- 2015
15. Tephrochronology of the upper Río Cisnes valley (44°S), southern Chile
- Author
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Stern,Charles R, de Porras,María Eugenia, and Maldonado,Antonio
- Subjects
Tephra ,Volcanism ,Andes ,Tephrochronology ,Tephrostratigraphy ,Chile - Abstract
Based on their petrography and chemistry, 18 tephra analyzed from two lake and bog cores and one outcrop in the upper Río Cisnes valley are believed to have been derived from nine different eruptions of the Mentolat volcano, four of the Melimoyu volcano, and one from the Hudson volcano. Some of these tephra correlate chronologically and petrochemically with previously documented large eruptions of these volcanoes, including the Late-Glacial Ho eruption of Hudson (17,340 cal yrs BP), the mid-Holocene MEN1 eruption of Mentolat (7,710 cal yrs BP), and the Late-Holocene MEL2 eruption of Melimoyu (1,680 cal yrs BP). A Melimoyu-derived tephra from the outcrop occurs in glacial-lacustrine sediments and is considered to pre-date the Last Glacial Maximum (>19,670 cal yrs BP). The data suggest that none of the tephra were produced by explosive eruptions of the Maca, Cay and Yanteles volcanoes.
- Published
- 2015
16. Tephrochronology of the upper Río Cisnes valley (44°S), southern Chile
- Author
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Stern, Charles R, de Porras, María Eugenia, and Maldonado, Antonio
- Subjects
Tephra ,Volcanism ,Volcanismo ,Tefrostratigrafía ,Tefra ,Andes ,Tefrocronología ,Tephrochronology ,Tephrostratigraphy ,Chile - Abstract
Based on their petrography and chemistry, 18 tephra analyzed from two lake and bog cores and one outcrop in the upper Río Cisnes valley are believed to have been derived from nine different eruptions of the Mentolat volcano, four of the Melimoyu volcano, and one from the Hudson volcano. Some of these tephra correlate chronologically and petrochemically with previously documented large eruptions of these volcanoes, including the Late-Glacial Ho eruption of Hudson (17,340 cal yrs BP), the mid-Holocene MEN1 eruption of Mentolat (7,710 cal yrs BP), and the Late-Holocene MEL2 eruption of Melimoyu (1,680 cal yrs BP). A Melimoyu-derived tephra from the outcrop occurs in glacial-lacustrine sediments and is considered to pre-date the Last Glacial Maximum (>19,670 cal yrs BP). The data suggest that none of the tephra were produced by explosive eruptions of the Maca, Cay and Yanteles volcanoes. Dieciocho tefras provenientes de testigos de un lago y un mallín, junto a un perfil expuesto en el alto valle del río Cisnes fueron caracterizadas sobre la base de su petrografía y química y corresponderían a nueve diferentes erupciones del volcán Mentolat, cuatro del volcán Melimoyu y una del volcán Hudson. Algunas de estas tefras se correlacionan cronológica y petroquímicamente con grandes erupciones de estos volcanes previamente documentadas, incluyendo la erupción Ho del volcán Hudson (Tardiglacial, 17.340 años cal. AP), la erupción MEN1 del volcán Mentolat (Holoceno medio, 7.710 años cal. AP) y la erupción MEL2 del volcán Melimoyu (Holoceno tardío, 1.680 años cal. AP). Una tefra perteneciente a la erupción del volcán Melimoyu, hallada en un perfil expuesto en un contexto de depósitos glaciolacustres, tiene una edad (>19.670 años cal. AP) que precede al término del Último Máximo Glacial en Patagonia Central. Los datos sugieren que ninguna de las tefras fueron producidas por erupciones explosivas de los volcanes Maca, Cay y Yanteles.
- Published
- 2015
17. Tefrocronología en curso superior del valle del río Cisne (44°S), Chile Austral.
- Author
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Stern, Charles, primary, De Porras, María Eugenia, additional, and Maldonado, Antonio, additional
- Published
- 2015
- Full Text
- View/download PDF
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