Gino Figueroa | Universidad Andrés Bello (original) (raw)
Videos by Gino Figueroa
Primer módulo del curso online gratuito "Introducción a la Geología" te invito a contestar la eva... more Primer módulo del curso online gratuito "Introducción a la Geología" te invito a contestar la evaluación formativa correspondiente una vez finalizado el vídeo y leído el Capitulo 1 y 22 del libro base "Tarbuck, 2005 (Introducción a la Geología y Geología Planetaria - Páginas 1-32 y 623-652)". Todas tus consultas y/o comentarios sobre este módulo puedes realizarlas por este medio, las preguntas más frecuentes o importantes serán contestadas en el próximo vídeo. Este curso es online y por tanto de aprendizaje asincrónico, puedes estudiar y aprender en los tiempos que tu estimes conveniente.
Evaluación Módulo 1: https://forms.gle/XbWGxxhcLVzSPEyu5
Buscar en Google: Tarbuck (2005). Ciencias de la Tierra. Una Introducción a la Geología física.
¿Como participar del curso?
https://www.hrgeoservicios.cl/2022/09/curso-online-gratuito-introduccion-la.html
¿Deseas acceder a contenido exclusivo? Suscribete por $5 USD
https://www.patreon.com/jovageology
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Segundo módulo del curso online gratuito "Introducción a la Geología" te invito a contestar la ev... more Segundo módulo del curso online gratuito "Introducción a la Geología" te invito a contestar la evaluación formativa correspondiente una vez finalizado el vídeo y leído el Capitulo 3 del libro base "Tarbuck, 2005 (Materia y Minerales - Páginas 77-106)". Todas tus consultas y/o comentarios sobre este módulo puedes realizarlas por este medio, las preguntas más frecuentes o importantes serán contestadas en el próximo vídeo. Este curso es online y por tanto de aprendizaje asincrónico, puedes estudiar y aprender en los tiempos que tu estimes conveniente.
Evaluación Módulo 2: https://forms.gle/DRPHaLWmV1R6Ht8F6
Buscar en Google: Tarbuck (2005). Ciencias de la Tierra. Una Introducción a la Geología física.
¿Como participar del curso?
https://www.hrgeoservicios.cl/2022/09/curso-online-gratuito-introduccion-la.html
¿Deseas acceder a contenido exclusivo? Suscríbite por $5 USD
https://www.patreon.com/jovageology
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Other by Gino Figueroa
Trabajo de Geología estudiantes de tercer año, correspondiente al curso de Geología de campo. El ... more Trabajo de Geología estudiantes de tercer año, correspondiente al curso de Geología de campo. El siguiente informe presenta el trabajo de campo realizado en el Rincón de Los Valles durante los días 20 al 25 de abril del año 2015 entre las coordenadas 70°42'00'' - 70°47'57'' y 32°53'37'' - 32°59'36'' al oeste de San Felipe, en el límite este de la Región de Valparaíso y norte de la región Metropolitana. El trabajo consistió en la aplicación de los métodos de mapeo geológico con el fin de analizar e interpretar los datos obtenidos en terreno y así asociarlos a una historia geológica coherente.
El presente informe muestra el trabajo de campo realizado en el área de Tilama, durante los días ... more El presente informe muestra el trabajo de campo realizado en el área de Tilama, durante los días 22
al 29 de Agosto, del presente año. El objetivo principal es confeccionar un mapa geológico 1:10000,
además de dar a entender la geología y evolución del sector desde su génesis. Gran parte de los
procesos observados y descritos corresponden a eventos Cretácicos que poseen diversos estudios
en Chile, ligados estrechamente al margen tectónico que reinaba durante ese periodo. Esto incluye
transgresiones y regresiones marinas, así como al evento deformativo de escala continental,
conocido como fase peruana. Esta dinámica produjo gran cantidad de estructuras las que se asocian
a movimientos de tipo dextral según el modelo de Ridell. Este cizalle ocurre en las rocas volcánicas
de la Formación Quebrada Marquesa, bajo un ambiente dúctil, evidenciado por milonitas. Este cizalle
permanece activo durante el emplazamiento del plutón CPI que aflora en el área, el que provoca un
basculamiento de las rocas hacia el este mediante el mecanismo de bending.
Conference Presentations by Gino Figueroa
I Jornada de Geología Marina - UNAB, 2019
Subsidence associated to the 1960 Chile earthquake (Mw 9.5) produced conspicuous changes on the c... more Subsidence associated to the 1960 Chile earthquake (Mw 9.5) produced conspicuous changes on the coast of a beach ridge plain midway along its rupture. As result of ⁓1.5 m of coseismic subsidence and ⁓5 km of tsunami inland inundation, the Pangal plain shoreline was eroded during the following twenty years. However, since 1980 it began to recover back building a series of beach ridges and a beach. Airphotos along with satellite images were used to estimate the shoreline change rate using a SIG and the DSAS add-in. Morphology was obtained through dGPS, referred to local sea level, and analyzed by DEM and SwathProfiler. Trenches and auger pits logging, GPR profiles, and grain-size analyses were used to describe the plain´s stratigraphy. All this allowed us to characterize the shoreline´s morphostratigraphic evolution. The plain retreated in average 331 m between 1960 and 1980. Remarkably, it prograded 302 m afterwards but without recovering its pre-1960 position yet. During its recovery three beach ridges, with different widths and heights, were formed. The farthest inland ridge, and first abandoned, buried the 1960 soil, a tabular sand sheet, the post 1960 soil and an erosional scarp. We interpret all these features as produced by the 1960 subsidence and ensuing tsunami. We proposed two models to understand the shoreline erosion process by coseismic subsidence, and the subsequent recovery until today. Due the evidence are clear, provide a modern analog to similar characteristics found inland of Pangal.
XV Congreso Geológico Chileno, 2018
As a result of ~ 1.5 m of co-seismic subsidence associated to the giant 1960 Chile earthquake, th... more As a result of ~ 1.5 m of co-seismic subsidence associated to the giant 1960 Chile earthquake, the shoreline of Pangal, a beach-ridge plain located midway along the 1960 subsided area, retreated ~400 m landward by erosion. Twenty years later, by 1979, the shoreline started to prograde seaward constructing a series of beach ridges and a wide beach. Today, the shoreline is ~150 m seaward from its pre-1960 position. Stratigraphy recorded this story through a scarp buried at the most landward reach of the retreat. The scarp is marked by a truncated 1960 soil and concentrations of heavy minerals and organic wrack. All these features are now buried by the backmost ridge constructed after 1979. Remarkably, all this evolution occurred without evident post-1960 coastal level change. Shoreline morphological evolution of Pangal was inferred using a set of pre and post-1960 airphotos along with more recent satellite images. The spatial analysis was made with a GIS. While topographic profiles were made using a regular level and dGPS, surface topography was carried out by photogrammetry using a drone. We linked all the elevation data to a local mean sea level estimated by measuring the water level continuously for one week with a portable acoustic tide gauge. The resulting tide record was fitted to tidal predictions from the TPXO 8-atlas tidal model. The stratigraphy of the area that was eroded and then recovered after 1960 was obtained from hand-auger holes and shovel pits. Pits were not very useful, because being the sand saturated with water, the sand used to collapse easily. Additionally, we performed GPR profiles using an antenna with a frequency of 250 MHz. Our results allow us to characterize the shoreline geomorphological and stratigraphic effects generated by co-seismic subsidence in 1960. Because the traces left are so obvious, including a buried scarp and a beach ridge, they provide a modern analog for similar features found inland. If so, they promise for extending the earthquake history farther back in time.
Cities on Volcanoes 9, 2016
A frequent volcanic activity is part of the landscape dynamic in Chile. However, only a few studi... more A frequent volcanic activity is part of the landscape dynamic in Chile. However, only a few studies about the chemical changes in environment surrounding southern Andean volcanoes have been addressed. Providing an annual resolution, the study of the tree-rings in Andean forests can be a novel approach to study these environmental changes. The main objective of this study was to assessing the relationship between the elemental composition of Araucaria araucana growth-rings during eruptive events of different volcanic explosivity index of Villarrica volcanoe. Dendrochronological samples from Araucaria araucana trees were taken in three sites: two in slopes of the Villarrica volcano (CHA01C and CHA02C), and one site located 64 kilometers away from this volcano (LAN01C). Using Araucaria growth series perfectly cross-dated, composite samples biannually from several trees were built. Using these composite samples, 17 chemical elements were analysed using ICP-MS in periods of 21 years, ten years before and after selected eruptions: 1822 (VEI = 2), 1915 (VEI = 1), 1963 (VEI = 3) y 1984 (VEI = 2). In the most of the analysed elements the chemical variability did not show a specific response to the eruption years. However, an increase in the concentration of Cu, Pb and Zn in the period from 1905 to 1925 in composite samples from Villarrica's sites occurs possibly associated to a higher eruptions frequency of Villarrica volcano in this period. Also, in some eruptions these metals presented well defined pulses in the same year or after two years since the eruption events. The long extension of the Araucaria tree-ring chronologies could be used as a high resolution paleo-record of volcanic eruption. The input of heavy metals in forest ecosystems and other natural resources could be studied using dendrochemical approaches.
Teaching Documents by Gino Figueroa
Presentación PDF de la charla interactiva del ciclo geológico de las rocas disponible en el canal... more Presentación PDF de la charla interactiva del ciclo geológico de las rocas disponible en el canal de Youtube de JovaGeology: https://youtu.be/oVMCNrfDlEA
Guía para el reconocimiento de minerales en muestra de mano, propiedades físicas y químicas. Cont... more Guía para el reconocimiento de minerales en muestra de mano, propiedades físicas y químicas. Contiene una breve descripción del ambiente geológico.
Yacimientos de reemplazo metasomático (también llamados metamórficos hidrotermales, metamórficos ... more Yacimientos de reemplazo metasomático (también llamados metamórficos hidrotermales, metamórficos ígneos, metamórficos de contacto, pirometasomáticos), en los cuales se han introducido cantidades de Si, Al, Fe y Mg. Las rocas se caracterizan por contener minerales calcosilicatados de Ca, Fe, Mg y Mn; como granate (andradita, grosularia, almandino), diópsido, wollastonita, tremolita-actinolita, scheelita, smectita (arcilla), clorita, epidota, talco, entre otros. La mineralización metálica asociada puede ser de W, Cu, Zn, Pb, Sn, Fe-Ca menor Au-Ag (Townley, 2001).
Los depósitos epitermales se caracterizan por estar a profundidades entre 1 a 2 kilómetros y ser ... more Los depósitos epitermales se caracterizan por estar a profundidades entre 1 a 2 kilómetros y ser yacimientos de metales preciosos, donde la mineralización es producto de fluidos hidrotermales calientes con temperaturas entre 100-320°C. La mineralización es principalmente de Au y Ag con sulfuros de metales base como Cu, Pb y Zn. Se distinguen dos tipos químicos de fluidos (ver figura 1): los de baja sulfuración (BS) que son una mezcla de aguas meteóricas que percolan al subsuelo y aguas magmáticas derivadas de roca fundida a gran profundidad que han ascendido a la superficie, y los de alta sulfuración (AS) derivados de una fuente magmática que ha depositado metales cerca de las superficie cuando el fluido se enfría o mezcla con aguas meteóricas (Maksaev, 2001). Fig. 1. Modelo simplificado para los depósitos de alta, intermedia y baja sulfuración (Sillitoe, 1995; González, 2008). Asociados a volcanismo terciario con rocas de carácter alcalino, estos depósitos se presentan principalmente en zonas de borde continental activos con zonas de subducción, en dos tipos de
Una guía creada para el reconocimiento de minerales de mena en microscopio de luz reflejada, entr... more Una guía creada para el reconocimiento de minerales de mena en microscopio de luz reflejada, entre ellos: calcopirita, enargita, galena, magnetita y otros.
Una guía creada para el reconocimiento de minerales en secciones delgadas: nesosilicatos, sorosil... more Una guía creada para el reconocimiento de minerales en secciones delgadas: nesosilicatos, sorosilicatos, ciclosilicatos, inosilicatos, filosilicatos, tectosilicatos y otros.
Papers by Gino Figueroa
AGU Fall Meeting Abstracts, Dec 1, 2019
Quaternary Science Reviews, 2021
As a result of ~ 1.5 m of co-seismic subsidence associated to the giant 1960 Chile earthquake, th... more As a result of ~ 1.5 m of co-seismic subsidence associated to the giant 1960 Chile earthquake, the shoreline of Pangal, a beach-ridge plain located midway along the 1960 subsided area, retreated ~400 m landward by erosion. Twenty years later, by 1979, the shoreline started to prograde seaward constructing a series of beach ridges and a wide beach. Today, the shoreline is ~150 m seaward from its pre-1960 position. Stratigraphy recorded this story through a scarp buried at the most landward reach of the retreat. The scarp is marked by a truncated 1960 soil and concentrations of heavy minerals and organic wrack. All these features are now buried by the backmost ridge constructed after 1979. Remarkably, all this evolution occurred without evident post-1960 coastal level change. Shoreline morphological evolution of Pangal was inferred using a set of pre and post-1960 airphotos along with more recent satellite images. The spatial analysis was made with a GIS. While topographic profiles were made using a regular level and dGPS, surface topography was carried out by photogrammetry using a drone. We linked all the elevation data to a local mean sea level estimated by measuring the water level continuously for one week with a portable acoustic tide gauge. The resulting tide record was fitted to tidal predictions from the TPXO 8-atlas tidal model. The stratigraphy of the area that was eroded and then recovered after 1960 was obtained from hand-auger holes and shovel pits. Pits were not very useful, because being the sand saturated with water, the sand used to collapse easily. Additionally, we performed GPR profiles using an antenna with a frequency of 250 MHz. Our results allow us to characterize the shoreline geomorphological and stratigraphic effects generated by co-seismic subsidence in 1960. Because the traces left are so obvious, including a buried scarp and a beach ridge, they provide a modern analog for similar features found inland. If so, they promise for extending the earthquake history farther back in time.
Thesis Chapters by Gino Figueroa
This paper presents new morpho-stratigraphic evidence of subsidence caused by the 1960 Valdivia e... more This paper presents new morpho-stratigraphic evidence of subsidence caused by the 1960 Valdivia earthquake in Pangal, a coastal strand plain located approximately 60 km southwest of the city of Puerto Montt. With a magnitude of 9.5, the 1960 earthquake, the largest instrumentally recorded earthquake in the world, subsided the Pangal area about 1.5 m and generated a tsunami that inundated up to 5 km inland. The morpho-stratigraphic evidence includes: (1) an erosional scarp produced by the receding coastline after the earthquake and during the next two decades, (2) a layer of sand between two layers of soil associated with the tsunami, and (3) the build of a new beach ridges covering the scarp and extending toward the ocean. A few meters landward of these evidences are located the maximum retreat lines of paleocoasts associated to coseismic subsidence (PMRS) of each ancient event recorded in the area. Similar morpho-stratigraphic records are also recognized in the inland part of the plain and are associated with subsidence events caused by past earthquakes. Using the evidence of 1960 event as a modern analog together with the location of the PMRS of past events, this allows us to determine the retreat values and consequent subsidence associated with earthquakes occurred during the last two millennia in the center of the rupture area of the giant earthquake of 1960. To estimate the rate of longitudinal change of the coastline, we combined aerial photographs with satellite images in a geographic information system (GIS), using a digital shoreline analysis system (DSAS). Using a differential GPS and elevation data provided by SHOA, we built a digital elevation model (DEM) and topography profiles (Swath Profile), both referenced to local sea level. For the stratigraphic description of the plain we used the geological record of pits and wells, together with ground-penetrating radar profiles. Additionally, we used a new methodology for determining paleosubsidence: Bruun's rule, a theory for estimating the magnitude of shoreline retreat in response to sea level rise (in our case, caused by coastal subsidence). This methodology was previously calibrated with the subsidence and retreat observed for the 1960 earthquake (modern analogue). The results show that the plain retreated, on average, 330 m after the 1960 earthquake, between ~1961 and ~1980. Subsequently, the coastline motion changed direction and commenced to prograde, a process that continues to today. Actually, the coast today is even more seaward than before the earthquake. During the progradation, three distinct beach ridges were formed. The one located farther inland, marking the 1960 PMRS, buried an erosional scarp that cut the stratigraphic sequence, consisting of soil from 1960, an intermediate sand layer interpreted as the 1960 tsunami deposit, and thin soil developed in the time between the earthquake and maximum coastal retreat. By linking this morphostratigraphic evidence with the 1.5 m of subsidence generated by 1960 earthquake in Pangal, we used the PMRS of past earthquakes to estimate paleosubsidence. Compared to 1960, the ~1300 and 1575 AD earthquakes generated smaller subsidence, and the other two, in ~800 and ~1100 AD, generated larger subsidence. The paleoseismological approach applied in this work seems promising as a new approach for other subduction zones.
Primer módulo del curso online gratuito "Introducción a la Geología" te invito a contestar la eva... more Primer módulo del curso online gratuito "Introducción a la Geología" te invito a contestar la evaluación formativa correspondiente una vez finalizado el vídeo y leído el Capitulo 1 y 22 del libro base "Tarbuck, 2005 (Introducción a la Geología y Geología Planetaria - Páginas 1-32 y 623-652)". Todas tus consultas y/o comentarios sobre este módulo puedes realizarlas por este medio, las preguntas más frecuentes o importantes serán contestadas en el próximo vídeo. Este curso es online y por tanto de aprendizaje asincrónico, puedes estudiar y aprender en los tiempos que tu estimes conveniente.
Evaluación Módulo 1: https://forms.gle/XbWGxxhcLVzSPEyu5
Buscar en Google: Tarbuck (2005). Ciencias de la Tierra. Una Introducción a la Geología física.
¿Como participar del curso?
https://www.hrgeoservicios.cl/2022/09/curso-online-gratuito-introduccion-la.html
¿Deseas acceder a contenido exclusivo? Suscribete por $5 USD
https://www.patreon.com/jovageology
5 views
Segundo módulo del curso online gratuito "Introducción a la Geología" te invito a contestar la ev... more Segundo módulo del curso online gratuito "Introducción a la Geología" te invito a contestar la evaluación formativa correspondiente una vez finalizado el vídeo y leído el Capitulo 3 del libro base "Tarbuck, 2005 (Materia y Minerales - Páginas 77-106)". Todas tus consultas y/o comentarios sobre este módulo puedes realizarlas por este medio, las preguntas más frecuentes o importantes serán contestadas en el próximo vídeo. Este curso es online y por tanto de aprendizaje asincrónico, puedes estudiar y aprender en los tiempos que tu estimes conveniente.
Evaluación Módulo 2: https://forms.gle/DRPHaLWmV1R6Ht8F6
Buscar en Google: Tarbuck (2005). Ciencias de la Tierra. Una Introducción a la Geología física.
¿Como participar del curso?
https://www.hrgeoservicios.cl/2022/09/curso-online-gratuito-introduccion-la.html
¿Deseas acceder a contenido exclusivo? Suscríbite por $5 USD
https://www.patreon.com/jovageology
3 views
Trabajo de Geología estudiantes de tercer año, correspondiente al curso de Geología de campo. El ... more Trabajo de Geología estudiantes de tercer año, correspondiente al curso de Geología de campo. El siguiente informe presenta el trabajo de campo realizado en el Rincón de Los Valles durante los días 20 al 25 de abril del año 2015 entre las coordenadas 70°42'00'' - 70°47'57'' y 32°53'37'' - 32°59'36'' al oeste de San Felipe, en el límite este de la Región de Valparaíso y norte de la región Metropolitana. El trabajo consistió en la aplicación de los métodos de mapeo geológico con el fin de analizar e interpretar los datos obtenidos en terreno y así asociarlos a una historia geológica coherente.
El presente informe muestra el trabajo de campo realizado en el área de Tilama, durante los días ... more El presente informe muestra el trabajo de campo realizado en el área de Tilama, durante los días 22
al 29 de Agosto, del presente año. El objetivo principal es confeccionar un mapa geológico 1:10000,
además de dar a entender la geología y evolución del sector desde su génesis. Gran parte de los
procesos observados y descritos corresponden a eventos Cretácicos que poseen diversos estudios
en Chile, ligados estrechamente al margen tectónico que reinaba durante ese periodo. Esto incluye
transgresiones y regresiones marinas, así como al evento deformativo de escala continental,
conocido como fase peruana. Esta dinámica produjo gran cantidad de estructuras las que se asocian
a movimientos de tipo dextral según el modelo de Ridell. Este cizalle ocurre en las rocas volcánicas
de la Formación Quebrada Marquesa, bajo un ambiente dúctil, evidenciado por milonitas. Este cizalle
permanece activo durante el emplazamiento del plutón CPI que aflora en el área, el que provoca un
basculamiento de las rocas hacia el este mediante el mecanismo de bending.
I Jornada de Geología Marina - UNAB, 2019
Subsidence associated to the 1960 Chile earthquake (Mw 9.5) produced conspicuous changes on the c... more Subsidence associated to the 1960 Chile earthquake (Mw 9.5) produced conspicuous changes on the coast of a beach ridge plain midway along its rupture. As result of ⁓1.5 m of coseismic subsidence and ⁓5 km of tsunami inland inundation, the Pangal plain shoreline was eroded during the following twenty years. However, since 1980 it began to recover back building a series of beach ridges and a beach. Airphotos along with satellite images were used to estimate the shoreline change rate using a SIG and the DSAS add-in. Morphology was obtained through dGPS, referred to local sea level, and analyzed by DEM and SwathProfiler. Trenches and auger pits logging, GPR profiles, and grain-size analyses were used to describe the plain´s stratigraphy. All this allowed us to characterize the shoreline´s morphostratigraphic evolution. The plain retreated in average 331 m between 1960 and 1980. Remarkably, it prograded 302 m afterwards but without recovering its pre-1960 position yet. During its recovery three beach ridges, with different widths and heights, were formed. The farthest inland ridge, and first abandoned, buried the 1960 soil, a tabular sand sheet, the post 1960 soil and an erosional scarp. We interpret all these features as produced by the 1960 subsidence and ensuing tsunami. We proposed two models to understand the shoreline erosion process by coseismic subsidence, and the subsequent recovery until today. Due the evidence are clear, provide a modern analog to similar characteristics found inland of Pangal.
XV Congreso Geológico Chileno, 2018
As a result of ~ 1.5 m of co-seismic subsidence associated to the giant 1960 Chile earthquake, th... more As a result of ~ 1.5 m of co-seismic subsidence associated to the giant 1960 Chile earthquake, the shoreline of Pangal, a beach-ridge plain located midway along the 1960 subsided area, retreated ~400 m landward by erosion. Twenty years later, by 1979, the shoreline started to prograde seaward constructing a series of beach ridges and a wide beach. Today, the shoreline is ~150 m seaward from its pre-1960 position. Stratigraphy recorded this story through a scarp buried at the most landward reach of the retreat. The scarp is marked by a truncated 1960 soil and concentrations of heavy minerals and organic wrack. All these features are now buried by the backmost ridge constructed after 1979. Remarkably, all this evolution occurred without evident post-1960 coastal level change. Shoreline morphological evolution of Pangal was inferred using a set of pre and post-1960 airphotos along with more recent satellite images. The spatial analysis was made with a GIS. While topographic profiles were made using a regular level and dGPS, surface topography was carried out by photogrammetry using a drone. We linked all the elevation data to a local mean sea level estimated by measuring the water level continuously for one week with a portable acoustic tide gauge. The resulting tide record was fitted to tidal predictions from the TPXO 8-atlas tidal model. The stratigraphy of the area that was eroded and then recovered after 1960 was obtained from hand-auger holes and shovel pits. Pits were not very useful, because being the sand saturated with water, the sand used to collapse easily. Additionally, we performed GPR profiles using an antenna with a frequency of 250 MHz. Our results allow us to characterize the shoreline geomorphological and stratigraphic effects generated by co-seismic subsidence in 1960. Because the traces left are so obvious, including a buried scarp and a beach ridge, they provide a modern analog for similar features found inland. If so, they promise for extending the earthquake history farther back in time.
Cities on Volcanoes 9, 2016
A frequent volcanic activity is part of the landscape dynamic in Chile. However, only a few studi... more A frequent volcanic activity is part of the landscape dynamic in Chile. However, only a few studies about the chemical changes in environment surrounding southern Andean volcanoes have been addressed. Providing an annual resolution, the study of the tree-rings in Andean forests can be a novel approach to study these environmental changes. The main objective of this study was to assessing the relationship between the elemental composition of Araucaria araucana growth-rings during eruptive events of different volcanic explosivity index of Villarrica volcanoe. Dendrochronological samples from Araucaria araucana trees were taken in three sites: two in slopes of the Villarrica volcano (CHA01C and CHA02C), and one site located 64 kilometers away from this volcano (LAN01C). Using Araucaria growth series perfectly cross-dated, composite samples biannually from several trees were built. Using these composite samples, 17 chemical elements were analysed using ICP-MS in periods of 21 years, ten years before and after selected eruptions: 1822 (VEI = 2), 1915 (VEI = 1), 1963 (VEI = 3) y 1984 (VEI = 2). In the most of the analysed elements the chemical variability did not show a specific response to the eruption years. However, an increase in the concentration of Cu, Pb and Zn in the period from 1905 to 1925 in composite samples from Villarrica's sites occurs possibly associated to a higher eruptions frequency of Villarrica volcano in this period. Also, in some eruptions these metals presented well defined pulses in the same year or after two years since the eruption events. The long extension of the Araucaria tree-ring chronologies could be used as a high resolution paleo-record of volcanic eruption. The input of heavy metals in forest ecosystems and other natural resources could be studied using dendrochemical approaches.
Presentación PDF de la charla interactiva del ciclo geológico de las rocas disponible en el canal... more Presentación PDF de la charla interactiva del ciclo geológico de las rocas disponible en el canal de Youtube de JovaGeology: https://youtu.be/oVMCNrfDlEA
Guía para el reconocimiento de minerales en muestra de mano, propiedades físicas y químicas. Cont... more Guía para el reconocimiento de minerales en muestra de mano, propiedades físicas y químicas. Contiene una breve descripción del ambiente geológico.
Yacimientos de reemplazo metasomático (también llamados metamórficos hidrotermales, metamórficos ... more Yacimientos de reemplazo metasomático (también llamados metamórficos hidrotermales, metamórficos ígneos, metamórficos de contacto, pirometasomáticos), en los cuales se han introducido cantidades de Si, Al, Fe y Mg. Las rocas se caracterizan por contener minerales calcosilicatados de Ca, Fe, Mg y Mn; como granate (andradita, grosularia, almandino), diópsido, wollastonita, tremolita-actinolita, scheelita, smectita (arcilla), clorita, epidota, talco, entre otros. La mineralización metálica asociada puede ser de W, Cu, Zn, Pb, Sn, Fe-Ca menor Au-Ag (Townley, 2001).
Los depósitos epitermales se caracterizan por estar a profundidades entre 1 a 2 kilómetros y ser ... more Los depósitos epitermales se caracterizan por estar a profundidades entre 1 a 2 kilómetros y ser yacimientos de metales preciosos, donde la mineralización es producto de fluidos hidrotermales calientes con temperaturas entre 100-320°C. La mineralización es principalmente de Au y Ag con sulfuros de metales base como Cu, Pb y Zn. Se distinguen dos tipos químicos de fluidos (ver figura 1): los de baja sulfuración (BS) que son una mezcla de aguas meteóricas que percolan al subsuelo y aguas magmáticas derivadas de roca fundida a gran profundidad que han ascendido a la superficie, y los de alta sulfuración (AS) derivados de una fuente magmática que ha depositado metales cerca de las superficie cuando el fluido se enfría o mezcla con aguas meteóricas (Maksaev, 2001). Fig. 1. Modelo simplificado para los depósitos de alta, intermedia y baja sulfuración (Sillitoe, 1995; González, 2008). Asociados a volcanismo terciario con rocas de carácter alcalino, estos depósitos se presentan principalmente en zonas de borde continental activos con zonas de subducción, en dos tipos de
Una guía creada para el reconocimiento de minerales de mena en microscopio de luz reflejada, entr... more Una guía creada para el reconocimiento de minerales de mena en microscopio de luz reflejada, entre ellos: calcopirita, enargita, galena, magnetita y otros.
Una guía creada para el reconocimiento de minerales en secciones delgadas: nesosilicatos, sorosil... more Una guía creada para el reconocimiento de minerales en secciones delgadas: nesosilicatos, sorosilicatos, ciclosilicatos, inosilicatos, filosilicatos, tectosilicatos y otros.
AGU Fall Meeting Abstracts, Dec 1, 2019
Quaternary Science Reviews, 2021
As a result of ~ 1.5 m of co-seismic subsidence associated to the giant 1960 Chile earthquake, th... more As a result of ~ 1.5 m of co-seismic subsidence associated to the giant 1960 Chile earthquake, the shoreline of Pangal, a beach-ridge plain located midway along the 1960 subsided area, retreated ~400 m landward by erosion. Twenty years later, by 1979, the shoreline started to prograde seaward constructing a series of beach ridges and a wide beach. Today, the shoreline is ~150 m seaward from its pre-1960 position. Stratigraphy recorded this story through a scarp buried at the most landward reach of the retreat. The scarp is marked by a truncated 1960 soil and concentrations of heavy minerals and organic wrack. All these features are now buried by the backmost ridge constructed after 1979. Remarkably, all this evolution occurred without evident post-1960 coastal level change. Shoreline morphological evolution of Pangal was inferred using a set of pre and post-1960 airphotos along with more recent satellite images. The spatial analysis was made with a GIS. While topographic profiles were made using a regular level and dGPS, surface topography was carried out by photogrammetry using a drone. We linked all the elevation data to a local mean sea level estimated by measuring the water level continuously for one week with a portable acoustic tide gauge. The resulting tide record was fitted to tidal predictions from the TPXO 8-atlas tidal model. The stratigraphy of the area that was eroded and then recovered after 1960 was obtained from hand-auger holes and shovel pits. Pits were not very useful, because being the sand saturated with water, the sand used to collapse easily. Additionally, we performed GPR profiles using an antenna with a frequency of 250 MHz. Our results allow us to characterize the shoreline geomorphological and stratigraphic effects generated by co-seismic subsidence in 1960. Because the traces left are so obvious, including a buried scarp and a beach ridge, they provide a modern analog for similar features found inland. If so, they promise for extending the earthquake history farther back in time.
This paper presents new morpho-stratigraphic evidence of subsidence caused by the 1960 Valdivia e... more This paper presents new morpho-stratigraphic evidence of subsidence caused by the 1960 Valdivia earthquake in Pangal, a coastal strand plain located approximately 60 km southwest of the city of Puerto Montt. With a magnitude of 9.5, the 1960 earthquake, the largest instrumentally recorded earthquake in the world, subsided the Pangal area about 1.5 m and generated a tsunami that inundated up to 5 km inland. The morpho-stratigraphic evidence includes: (1) an erosional scarp produced by the receding coastline after the earthquake and during the next two decades, (2) a layer of sand between two layers of soil associated with the tsunami, and (3) the build of a new beach ridges covering the scarp and extending toward the ocean. A few meters landward of these evidences are located the maximum retreat lines of paleocoasts associated to coseismic subsidence (PMRS) of each ancient event recorded in the area. Similar morpho-stratigraphic records are also recognized in the inland part of the plain and are associated with subsidence events caused by past earthquakes. Using the evidence of 1960 event as a modern analog together with the location of the PMRS of past events, this allows us to determine the retreat values and consequent subsidence associated with earthquakes occurred during the last two millennia in the center of the rupture area of the giant earthquake of 1960. To estimate the rate of longitudinal change of the coastline, we combined aerial photographs with satellite images in a geographic information system (GIS), using a digital shoreline analysis system (DSAS). Using a differential GPS and elevation data provided by SHOA, we built a digital elevation model (DEM) and topography profiles (Swath Profile), both referenced to local sea level. For the stratigraphic description of the plain we used the geological record of pits and wells, together with ground-penetrating radar profiles. Additionally, we used a new methodology for determining paleosubsidence: Bruun's rule, a theory for estimating the magnitude of shoreline retreat in response to sea level rise (in our case, caused by coastal subsidence). This methodology was previously calibrated with the subsidence and retreat observed for the 1960 earthquake (modern analogue). The results show that the plain retreated, on average, 330 m after the 1960 earthquake, between ~1961 and ~1980. Subsequently, the coastline motion changed direction and commenced to prograde, a process that continues to today. Actually, the coast today is even more seaward than before the earthquake. During the progradation, three distinct beach ridges were formed. The one located farther inland, marking the 1960 PMRS, buried an erosional scarp that cut the stratigraphic sequence, consisting of soil from 1960, an intermediate sand layer interpreted as the 1960 tsunami deposit, and thin soil developed in the time between the earthquake and maximum coastal retreat. By linking this morphostratigraphic evidence with the 1.5 m of subsidence generated by 1960 earthquake in Pangal, we used the PMRS of past earthquakes to estimate paleosubsidence. Compared to 1960, the ~1300 and 1575 AD earthquakes generated smaller subsidence, and the other two, in ~800 and ~1100 AD, generated larger subsidence. The paleoseismological approach applied in this work seems promising as a new approach for other subduction zones.