Emilio Pueyo - Academia.edu (original) (raw)

Papers by Emilio Pueyo

<p>Deciphering the tectono-thermal evolution of deformed foreland basins is fundame... more <p>Deciphering the tectono-thermal evolution of deformed foreland basins is fundamental for understanding the kinematics of mountain building processes. In orogenic systems, tectonic loading during early compressional stages produces the formation of foreland basins that, as compression progresses, are folded, exhumed and incorporated into the forming fold-and-thrust belts. These exhumed foreland basins represent excellent candidates for studying the early-orogenic burial conditions and geometries. The Jaca Basin, in the south-western Pyrenees, represents the primary south Pyrenean foreland basin that was latter deformed, piggy-back thrusted and embedded into the south Pyrenean fold-and-thrust belt. The basin displays a non-cylindrical geometry and it is filled by exceptionally preserved syn-orogenic sequences: early-middle Eocene turbidites that grade upwards to late Eocene marls and late Eocene-Oligocene and Miocene continental units. Debate exists on the timing of thrusting exhuming the basin, the geometry of basement thrusts and their link to syn-orogenic sedimentation and emerging cover structures. This debate sums up to the uncertainties on the basin thermal history, with previous paleo-thermal data being heterogeneously distributed and mostly concentrated in the eastern part of the basin.</p> <p>To reduce these uncertainties and contribute into the understanding of debated kinematic aspects, we carried out a combined structural and paleo-thermal study covering the eastern and central part of the deformed Jaca basin. Four sequential, seismic-based cross sections have been constructed whereas thermal and burial conditions along section traces have been constrained through Raman Spectroscopy on Carbonaceous Material (RSCM). Samples for RSCM have been collected from the Eocene turbidites and indicate maximum burial temperatures of ~200ºC at the base of the sedimentary sequence (northern part of the cross-sections) that decrease progressively to the south where younger turbidites crop-out. In the considered area, RSCM temperature estimates along specific cover thrusts indicate a westward increase of peak temperatures. Along-strike thermal variations are in line with seismic-based cross-sections that depict strong lateral changes in the geometry of the basement soling the Jaca basin. The top of the basement is at shallower positions in the central Jaca basin where the number of basement thrusts increases. Basement thrusts partly derive from the reactivation of inherited Permian-Triassic extensional faults and partition the eastern-central Jaca basin into two structural domains separated by a main, oblique basement ramp. From cross-sections and thermal estimates, this contribution allows reconstructing the tectono-thermal history of the Jaca basin from the early foreland basin stages to the advanced shortening stages both along its central and eastern segments.</p>

<p>The Middle Eocene Climate Optimum (MECO) was a 0.5 Myr warming interval that pun... more <p>The Middle Eocene Climate Optimum (MECO) was a 0.5 Myr warming interval that punctuated the long-term cooling trend of the middle to late Eocene. It has been identified worldwide by a gradual negative shift of the dO18 followed by a sharp return to the cooling trend. The peak warming at about 40 Ma coincides in some records with a sharp negative excursion of the d13C, which suggested a relation of the warming event with a transient increase of pCO<sub>2</sub>. Results from various records also point to increased seasonality and chemical weathering of the source area in coincidence with the MECO.</p> <p>The interval of the MECO is stratigraphically well constrained in the south-central Pyrenees, from the Graus-Trempto the Aínsa and Jaca basins thanks to previous biostratigraphic and magnetostratigraphic investigations. During this period, the south-Pyrenean foreland formed a narrow and shallow elongated basin connected to the west to the Atlantic Ocean. Here we present a record of the MECO in the carbonate platform succession (the Santo Domingo Member of the Arguis Fm.), that accumulated on the Iberian foreland margin, currently outcropping along the External Sierras (the frontal thrust sheet of the southern Pyrenees). Polished samples were micro-drilled to analyse the d18O and d13C isotopes ratios separately from the mud fraction and shells of different species of larger benthic foraminifera. The results show trends of the d18O from the mud fraction that parallel the global ocean isotope signature but with values that are offset towards more negative values (-4‰). There, the influence of the continental waters in the isotopic signal was possibly amplified by the restricted marine paleogeographic context.  Results from fossil shells gave values significantly different from the mud fraction: d18O from Nummulites shells were consistently offset towards more positive values compared to mud, which could indicate a different fractionation pathway or, alternatively, a preferred diagenetic alteration of fossil fragments. A sharp negative excursion of the d13C was identified in coincidence with the negative d18O peak, marking the location of the MECO. Noticeably, a short-lived entry of siliciclastics that replaced carbonate deposition is recorded at the time of the MECO peak, a feature comparable to what is documented in other sections of the eastern Jaca Basin, where a rapid pulse of deltaic sediments (Sabiñánigo sandstone) are embedded within a thick marine marl succession. Our observations agree with a scenario of perturbation of the hydrological cycle and transient increase of sediment discharge from the continent in coincidence with the MECO.</p>

Geologica Acta

An integrated study including magnetostratigraphy, larger benthic foraminifera and calcareous nan... more An integrated study including magnetostratigraphy, larger benthic foraminifera and calcareous nannofossil biostratigraphy is presented herein. This work was performed in shallow marine siliciclastics rich in larger foraminifera, around the Ypresian/Lutetian boundary in the Ésera valley (South-Central Pyrenees). Although the calcareous nannofossil content in the studied interval is low, not allowing a precise Y/L boundary to be recognised, the taxa found are enough to support the chronostratigraphic attribution. Data obtained in the Ésera valley section has improved the knowledge of larger benthic foraminifera (Nummulitesand Assilina) distribution through chron C21. SBZ 11 to SBZ 12 transition took place at the lowermost C21r, as shown in previous works. SBZ 12 assemblages extend into C21n, where the SBZ 12 to SBZ 13 boundary occurs. These data, obtained in shallow marine siliciclastic facies, with in situ fauna, results in a shift of the SBZ 12/SBZ 13 boundary to the Lower Lutetian,...

Geological Society of America Abstracts with Programs, 2017

Sociedad Geológica de España, Sep 1, 2016

: The Late Cretaceous in the westernmost sector of the External Sierras (Sto. Domingo range) is p... more : The Late Cretaceous in the westernmost sector of the External Sierras (Sto. Domingo range) is poorly represented but displays transitional facies where remains of continental and marine fossil vertebrates (Osteichthyes, Chondrichthyes and Dinosauria) were recently discovered. This paper introduces the preliminary magnetostratigraphic results carried out in 5 mini sections. The characteristic magnetization of these rocks is stable, primary and shows two polarities of the magnetic field. A tentative correlation considering our local sequence of polarities and the chronostratigraphy of vertebrates from the Graus-Tremp basin relates the fossil locality with the chron C32n (Campanian) and the Garum facies with C29r, C29n and C28r (Maastrichtian and Danian). This correlation implies a hiatus during the Maastrichtian and must be refined in future sedimentological studies, since no transitional facies were described so far in the Campanian.

DOI: 10.1344/GeologicaActa2021.19.7  R. Silva-Casal, J. Serra-Kiel, A. Rodríguez-Pintó, E.L. Pue... more DOI: 10.1344/GeologicaActa2021.19.7  R. Silva-Casal, J. Serra-Kiel, A. Rodríguez-Pintó, E.L. Pueyo, M. Aurell, A. Payros, 2021 CC BY-SA R . S i l v a C a s a l e t a l . G e o l o g i c a A c t a , 1 9 . 7 , 1 6 4 , I X V I I ( 2 0 2 1 ) D O I : 1 0 . 1 3 4 4 / G e o l o g i c a A c t a 2 0 2 1 . 1 9 . 7 Systematics of Lutetian larger foraminifera, South Pyrenean Basin

En la cuenca del rio Alcanadre (Depresion del Ebro, provincia de Huesca) se desarrolla una extens... more En la cuenca del rio Alcanadre (Depresion del Ebro, provincia de Huesca) se desarrolla una extensa secuencia de terrazas cuaternarias encajadas de tipo strath compuesta por nueve niveles (de Qt1 a Qt9). Se aportan nuevos datos cartograficos, altimetricos, estratigraficos, pedogeneticos y cronologicos. El ambiente sedimentario esta formado por sistemas fluviales entrelazados que incrementan el nivel de confinamiento conforme se encaja el drenaje. La morfologia del carbonato edafico alcanza estadios de maximo desarrollo (VI) con la edad. A partir de datos paleomagneticos, y de manera tentativa, el nivel mas antiguo Qt1 podria situarse cerca de los 1000 ka y el nivel Qt3 estaria en el entorno de los 780 ka. Mediante dataciones numericas de Luminiscencia Opticamente Estimulada (OSL) se han obtenido edades de 44 ± 2 ka, 19 ± 2 ka y 10 ± 1 ka para los niveles Qt5, Qt6 y Qt7. Estas terrazas presentan una buena correlacion con registros fluviales regionales localizados en cuencas hidrologic...

Geophysical Journal International, 2021

Summary Paleomagnetism is a versatile tool in the Earth sciences: it provides critical input to g... more Summary Paleomagnetism is a versatile tool in the Earth sciences: it provides critical input to geological time scales and plate tectonic reconstructions. Despite its undeniable perks, paleomagnetism is not without complications. Remagnetizations overprinting the original magnetic signature of rocks are frequent, especially in orogens which tend to be the areas with better rock exposure. Unraveling the magnetic history of the rocks is a complicated task, especially in areas that underwent several orogenic pulses. In turn, constraining the timing of remagnetization represents an opportunity to solve post-magnetization structural and tectonic kinematics. Here, we evaluate the magnetization history of Silurian-Devonian carbonates from the Axial Zone of the Pyrenees. The Pyrenees are a multi-orogenic mountain belt where Silurian-Devonian rocks have seen the Variscan collision (late Paleozoic), the opening of the Atlantic/Bay of Biscay (early Cretaceous) and the Alpine orogeny (late Cret...

<p>El suroeste de los Pirineos muestra algunas de l... more <p>El suroeste de los Pirineos muestra algunas de las características geométricas clave de la cordillera: 1) la terminación hacia el oeste del afloramiento principal de la Zona Axial, la columna vertebral de la cadena donde emergen las rocas del basamento 2) el afloramiento de unidades de basamento aisladas más al oeste (los llamados Macizos Vascos) y 3) la variación lateral de las geometrías de la corteza, caracterizada por la subestimación de la corteza ibérica inferior por debajo de la europea, con la corteza superior formando una cuña orogénica. El número, la secuencia, la cronología y las relaciones laterales de los empujes del sótano que forman esta cuña de la corteza superior son complejos y el foco del debate científico.</p><p>En este, mostramos el primer modelo 3D basado en la interpretación de 142 secciones de reflexión sísmica de tiempo disponible en la región (campañas PP, DP, JAT, JA, JAW, PJ & DP, que comprenden en total más de 1600 km de imágenes del subsuelo que cubren más de 9.000 km <sup>2</sup>). Para realizar la conversión de tiempo a profundidad, se considera un modelo de velocidad sísmica basado en registros sónicos de varios pozos (ecuación tiempo-profundidad promedio obtenida de los pozos Roncal-1, Sangüesa-1, Aoiz-1 y Pamplona sur). Los resultados preliminares de los datos sísmicos, superficiales y de pozos evidencian que la estructura del área de estudio consiste en un sistema de empuje imbricado en el sótano que está dirigido al sur y se conecta al sistema de cubierta de pliegue y empuje que forma las Sierras Externas. El sistema de empuje del sótano está separado dentro del Paleozoico (con un nivel de desprendimiento identificado a una profundidad de ~ 4 km por debajo de la parte superior del sótano) y avanzando hacia las evaporitas del Triásico Superior hacia el sur. El sistema de empuje del sótano involucra dos empujes principales que en parte resultan de la reactivación de fallas extensionales heredadas del Pérmico-Triásico durante la convergencia cenozoica. Producen con todo diferencias de altura del nivel estratigráfico de referencia (Cretácico Superior) de más de 8000 m. Unidades de sótano en el muro colgante del empuje norte (empuje de Gavarnie) progresivamente poco profundas hacia el este mientras que las unidades de sótano en la hoja de empuje sur (empuje de Guarga) poco profundas hacia el oeste. Las geometrías de los muros colgantes consiste en grandes paneles planos escalonados que también pueden complicarse con empujes de menor escala oblicuos a la principal tendencia pirenaica. </p>

<p>Deciphering the tectono-thermal evolution of deformed foreland basins is fundame... more <p>Deciphering the tectono-thermal evolution of deformed foreland basins is fundamental for understanding the kinematics of mountain building processes. In orogenic systems, tectonic loading during early compressional stages produces the formation of foreland basins that, as compression progresses, are folded, exhumed and incorporated into the forming fold-and-thrust belts. These exhumed foreland basins represent excellent candidates for studying the early-orogenic burial conditions and geometries. The Jaca Basin, in the south-western Pyrenees, represents the primary south Pyrenean foreland basin that was latter deformed, piggy-back thrusted and embedded into the south Pyrenean fold-and-thrust belt. The basin displays a non-cylindrical geometry and it is filled by exceptionally preserved syn-orogenic sequences: early-middle Eocene turbidites that grade upwards to late Eocene marls and late Eocene-Oligocene and Miocene continental units. Debate exists on the timing of thrusting exhuming the basin, the geometry of basement thrusts and their link to syn-orogenic sedimentation and emerging cover structures. This debate sums up to the uncertainties on the basin thermal history, with previous paleo-thermal data being heterogeneously distributed and mostly concentrated in the eastern part of the basin.</p> <p>To reduce these uncertainties and contribute into the understanding of debated kinematic aspects, we carried out a combined structural and paleo-thermal study covering the eastern and central part of the deformed Jaca basin. Four sequential, seismic-based cross sections have been constructed whereas thermal and burial conditions along section traces have been constrained through Raman Spectroscopy on Carbonaceous Material (RSCM). Samples for RSCM have been collected from the Eocene turbidites and indicate maximum burial temperatures of ~200ºC at the base of the sedimentary sequence (northern part of the cross-sections) that decrease progressively to the south where younger turbidites crop-out. In the considered area, RSCM temperature estimates along specific cover thrusts indicate a westward increase of peak temperatures. Along-strike thermal variations are in line with seismic-based cross-sections that depict strong lateral changes in the geometry of the basement soling the Jaca basin. The top of the basement is at shallower positions in the central Jaca basin where the number of basement thrusts increases. Basement thrusts partly derive from the reactivation of inherited Permian-Triassic extensional faults and partition the eastern-central Jaca basin into two structural domains separated by a main, oblique basement ramp. From cross-sections and thermal estimates, this contribution allows reconstructing the tectono-thermal history of the Jaca basin from the early foreland basin stages to the advanced shortening stages both along its central and eastern segments.</p>

<p>The Middle Eocene Climate Optimum (MECO) was a 0.5 Myr warming interval that pun... more <p>The Middle Eocene Climate Optimum (MECO) was a 0.5 Myr warming interval that punctuated the long-term cooling trend of the middle to late Eocene. It has been identified worldwide by a gradual negative shift of the dO18 followed by a sharp return to the cooling trend. The peak warming at about 40 Ma coincides in some records with a sharp negative excursion of the d13C, which suggested a relation of the warming event with a transient increase of pCO<sub>2</sub>. Results from various records also point to increased seasonality and chemical weathering of the source area in coincidence with the MECO.</p> <p>The interval of the MECO is stratigraphically well constrained in the south-central Pyrenees, from the Graus-Trempto the Aínsa and Jaca basins thanks to previous biostratigraphic and magnetostratigraphic investigations. During this period, the south-Pyrenean foreland formed a narrow and shallow elongated basin connected to the west to the Atlantic Ocean. Here we present a record of the MECO in the carbonate platform succession (the Santo Domingo Member of the Arguis Fm.), that accumulated on the Iberian foreland margin, currently outcropping along the External Sierras (the frontal thrust sheet of the southern Pyrenees). Polished samples were micro-drilled to analyse the d18O and d13C isotopes ratios separately from the mud fraction and shells of different species of larger benthic foraminifera. The results show trends of the d18O from the mud fraction that parallel the global ocean isotope signature but with values that are offset towards more negative values (-4‰). There, the influence of the continental waters in the isotopic signal was possibly amplified by the restricted marine paleogeographic context.  Results from fossil shells gave values significantly different from the mud fraction: d18O from Nummulites shells were consistently offset towards more positive values compared to mud, which could indicate a different fractionation pathway or, alternatively, a preferred diagenetic alteration of fossil fragments. A sharp negative excursion of the d13C was identified in coincidence with the negative d18O peak, marking the location of the MECO. Noticeably, a short-lived entry of siliciclastics that replaced carbonate deposition is recorded at the time of the MECO peak, a feature comparable to what is documented in other sections of the eastern Jaca Basin, where a rapid pulse of deltaic sediments (Sabiñánigo sandstone) are embedded within a thick marine marl succession. Our observations agree with a scenario of perturbation of the hydrological cycle and transient increase of sediment discharge from the continent in coincidence with the MECO.</p>

Geologica Acta

An integrated study including magnetostratigraphy, larger benthic foraminifera and calcareous nan... more An integrated study including magnetostratigraphy, larger benthic foraminifera and calcareous nannofossil biostratigraphy is presented herein. This work was performed in shallow marine siliciclastics rich in larger foraminifera, around the Ypresian/Lutetian boundary in the Ésera valley (South-Central Pyrenees). Although the calcareous nannofossil content in the studied interval is low, not allowing a precise Y/L boundary to be recognised, the taxa found are enough to support the chronostratigraphic attribution. Data obtained in the Ésera valley section has improved the knowledge of larger benthic foraminifera (Nummulitesand Assilina) distribution through chron C21. SBZ 11 to SBZ 12 transition took place at the lowermost C21r, as shown in previous works. SBZ 12 assemblages extend into C21n, where the SBZ 12 to SBZ 13 boundary occurs. These data, obtained in shallow marine siliciclastic facies, with in situ fauna, results in a shift of the SBZ 12/SBZ 13 boundary to the Lower Lutetian,...

Geological Society of America Abstracts with Programs, 2017

Sociedad Geológica de España, Sep 1, 2016

: The Late Cretaceous in the westernmost sector of the External Sierras (Sto. Domingo range) is p... more : The Late Cretaceous in the westernmost sector of the External Sierras (Sto. Domingo range) is poorly represented but displays transitional facies where remains of continental and marine fossil vertebrates (Osteichthyes, Chondrichthyes and Dinosauria) were recently discovered. This paper introduces the preliminary magnetostratigraphic results carried out in 5 mini sections. The characteristic magnetization of these rocks is stable, primary and shows two polarities of the magnetic field. A tentative correlation considering our local sequence of polarities and the chronostratigraphy of vertebrates from the Graus-Tremp basin relates the fossil locality with the chron C32n (Campanian) and the Garum facies with C29r, C29n and C28r (Maastrichtian and Danian). This correlation implies a hiatus during the Maastrichtian and must be refined in future sedimentological studies, since no transitional facies were described so far in the Campanian.

DOI: 10.1344/GeologicaActa2021.19.7  R. Silva-Casal, J. Serra-Kiel, A. Rodríguez-Pintó, E.L. Pue... more DOI: 10.1344/GeologicaActa2021.19.7  R. Silva-Casal, J. Serra-Kiel, A. Rodríguez-Pintó, E.L. Pueyo, M. Aurell, A. Payros, 2021 CC BY-SA R . S i l v a C a s a l e t a l . G e o l o g i c a A c t a , 1 9 . 7 , 1 6 4 , I X V I I ( 2 0 2 1 ) D O I : 1 0 . 1 3 4 4 / G e o l o g i c a A c t a 2 0 2 1 . 1 9 . 7 Systematics of Lutetian larger foraminifera, South Pyrenean Basin

En la cuenca del rio Alcanadre (Depresion del Ebro, provincia de Huesca) se desarrolla una extens... more En la cuenca del rio Alcanadre (Depresion del Ebro, provincia de Huesca) se desarrolla una extensa secuencia de terrazas cuaternarias encajadas de tipo strath compuesta por nueve niveles (de Qt1 a Qt9). Se aportan nuevos datos cartograficos, altimetricos, estratigraficos, pedogeneticos y cronologicos. El ambiente sedimentario esta formado por sistemas fluviales entrelazados que incrementan el nivel de confinamiento conforme se encaja el drenaje. La morfologia del carbonato edafico alcanza estadios de maximo desarrollo (VI) con la edad. A partir de datos paleomagneticos, y de manera tentativa, el nivel mas antiguo Qt1 podria situarse cerca de los 1000 ka y el nivel Qt3 estaria en el entorno de los 780 ka. Mediante dataciones numericas de Luminiscencia Opticamente Estimulada (OSL) se han obtenido edades de 44 ± 2 ka, 19 ± 2 ka y 10 ± 1 ka para los niveles Qt5, Qt6 y Qt7. Estas terrazas presentan una buena correlacion con registros fluviales regionales localizados en cuencas hidrologic...

Geophysical Journal International, 2021

Summary Paleomagnetism is a versatile tool in the Earth sciences: it provides critical input to g... more Summary Paleomagnetism is a versatile tool in the Earth sciences: it provides critical input to geological time scales and plate tectonic reconstructions. Despite its undeniable perks, paleomagnetism is not without complications. Remagnetizations overprinting the original magnetic signature of rocks are frequent, especially in orogens which tend to be the areas with better rock exposure. Unraveling the magnetic history of the rocks is a complicated task, especially in areas that underwent several orogenic pulses. In turn, constraining the timing of remagnetization represents an opportunity to solve post-magnetization structural and tectonic kinematics. Here, we evaluate the magnetization history of Silurian-Devonian carbonates from the Axial Zone of the Pyrenees. The Pyrenees are a multi-orogenic mountain belt where Silurian-Devonian rocks have seen the Variscan collision (late Paleozoic), the opening of the Atlantic/Bay of Biscay (early Cretaceous) and the Alpine orogeny (late Cret...

<p>El suroeste de los Pirineos muestra algunas de l... more <p>El suroeste de los Pirineos muestra algunas de las características geométricas clave de la cordillera: 1) la terminación hacia el oeste del afloramiento principal de la Zona Axial, la columna vertebral de la cadena donde emergen las rocas del basamento 2) el afloramiento de unidades de basamento aisladas más al oeste (los llamados Macizos Vascos) y 3) la variación lateral de las geometrías de la corteza, caracterizada por la subestimación de la corteza ibérica inferior por debajo de la europea, con la corteza superior formando una cuña orogénica. El número, la secuencia, la cronología y las relaciones laterales de los empujes del sótano que forman esta cuña de la corteza superior son complejos y el foco del debate científico.</p><p>En este, mostramos el primer modelo 3D basado en la interpretación de 142 secciones de reflexión sísmica de tiempo disponible en la región (campañas PP, DP, JAT, JA, JAW, PJ & DP, que comprenden en total más de 1600 km de imágenes del subsuelo que cubren más de 9.000 km <sup>2</sup>). Para realizar la conversión de tiempo a profundidad, se considera un modelo de velocidad sísmica basado en registros sónicos de varios pozos (ecuación tiempo-profundidad promedio obtenida de los pozos Roncal-1, Sangüesa-1, Aoiz-1 y Pamplona sur). Los resultados preliminares de los datos sísmicos, superficiales y de pozos evidencian que la estructura del área de estudio consiste en un sistema de empuje imbricado en el sótano que está dirigido al sur y se conecta al sistema de cubierta de pliegue y empuje que forma las Sierras Externas. El sistema de empuje del sótano está separado dentro del Paleozoico (con un nivel de desprendimiento identificado a una profundidad de ~ 4 km por debajo de la parte superior del sótano) y avanzando hacia las evaporitas del Triásico Superior hacia el sur. El sistema de empuje del sótano involucra dos empujes principales que en parte resultan de la reactivación de fallas extensionales heredadas del Pérmico-Triásico durante la convergencia cenozoica. Producen con todo diferencias de altura del nivel estratigráfico de referencia (Cretácico Superior) de más de 8000 m. Unidades de sótano en el muro colgante del empuje norte (empuje de Gavarnie) progresivamente poco profundas hacia el este mientras que las unidades de sótano en la hoja de empuje sur (empuje de Guarga) poco profundas hacia el oeste. Las geometrías de los muros colgantes consiste en grandes paneles planos escalonados que también pueden complicarse con empujes de menor escala oblicuos a la principal tendencia pirenaica. </p>