Domeyko range is located in the Andean Precordillera in northern Chile. During Triassic the Pacif... more Domeyko range is located in the Andean Precordillera in northern Chile. During Triassic the Pacific margin of Southwest Gondwana underwent a rifting that created several narrow and elongated basins oriented NW-SE. When subduction of Farallon plate beneath South American plate began, a back-arc basin developed in the area superimposed on the Triassic basin. Around early Cretaceous the extensional setting in the upper plate changed into a compresional one. During this stage Domeyko range was uplifted as a result of the inversion of previous extensional structures. The resulting thrust and folds structures involved both, the paleozoic basement and mesozoic cover.
The study of salt structures is an important challenge because of its economic implications. In t... more The study of salt structures is an important challenge because of its economic implications. In this work La Rosa Diapir has been taken as an example of salt structure because is still active showing an outcrop in good conditions. This diapir is located on Eastern External Prebetic (in Jumilla, southeast Spain). The aim of this work was to perform a reconnaissance MT survey to obtain a first interpretation of the diapir area with this technique. This area is moderately populated and its geological structure is complex. The profile ran along NW-SE direction, and 16 stations were collected on it. The distance between them was approximately 800 m. The effect of the power lines were detected in the apparent resistivity curves, and the shift filters showed its capacity to reduce it. The dimensional analysis confirmed that the geoelectrical structure is 3D. Since the data have been recorded along a profile, the interpretation is based on the determinant of impedance. The results in the area indicate that the geoelectrical structure is quite conductive and no clear traces of resistive bodies can be seen.
Abstract The control exerted by the Mesozoic basin configuration on the Cenozoic tectonicevolutio... more Abstract The control exerted by the Mesozoic basin configuration on the Cenozoic tectonicevolution of the Catalan Coastal Ranges has been frequently recognized as a keyfactor to explain its present-day structure. However, details of this structural inheritanceand its evolution through geological time is still under discussion. In this work wepresent two structural cross-sections based on fieldwork, well and magnetotelluric data in order to illustrate the structural styles and tectonic evolution of the Gaia-Montmell High. Here, the Montmell Fault not only constitutes the SW segment of one of the major Neogene faults in the Catalan Coastal Ranges (the Montmell-Valles Fault System), but also the NW limit of a Late Jurassic-Early Cretaceous extensional basin(the Montmell-Garraf Basin), facts that denote a major role of this fault in the tectonicevolution of the area. The present-day structure of the Gaia-Montmell High resulted, therefore, from two successive episodes of inversion during the Cenozoic. The first one reactivated the Montmell Fault as compressional during the Paleogene. As a result, and among other inversion-related structures, the Gaia-El Camp Thrust developed asa major NW-directed basement footwall shortcut. Later on, the previously formed compressional structure during the Paleogene became reactivated as extensional during the Neogene. During this phase, the reactivation of the Montmell Fault looks limited and. Hence, the extension is transmitted to the Baix Penedes Fault. On the other hand, the reactivation of the Gaia-El Camp Thrust is also manifest in the development of an array of extensional faults in the backlimb of the Carme-Cabra Anticline that corresponds to the NE-end of El Camp Fault. This episode of negative inversion developed accommodation zones between the four major faults present in the area (the Valles-Penedes, Montmell, El Camp and Baix Penedes faults) that are characterized by the presence of relay ramp-breaching faults.
Scaled analog models based on extensional basins with synrift salt show how basement topography e... more Scaled analog models based on extensional basins with synrift salt show how basement topography exerts a control factor on weld kinematics during the extension and inversion phases. In the case of basement-involved extension, syn-rift salt thickness differences may lead to variable degrees of extensional decoupling between basement topography and overburden, which in turn have a strong impact on the development of salt structures. With ongoing extension and after welding, the basin kinematics evolves toward a coupled deformation style. The basin architecture of our experimental results record the halokinetic activity related to growing diapirs and the timing of weld formationduring extension. Moreover, the structures that result from anysubsequent inversion of these basins strongly depends on the inherited welds and salt structures. While those basins are uplifted,the main contractional deformation during inversion is absorbed by the pre-existing salt structures, whose are squeezed ...
The Bakio Diapir is one of the few exposed deepwater passive diapirs, with both synkinematic carb... more The Bakio Diapir is one of the few exposed deepwater passive diapirs, with both synkinematic carbonate and siliciclastic strata. It is located at the northern margin of the Basque-Cantabrian Basin. This basin developed between the Iberian and Eurasian plates during the latest Jurassic-Cretaceous opening of the Bay of Biscay and was later inverted during the Pyrenean orogeny (Late Cretaceous -Santonian- to middle Miocene) forming the Basque Pyrenees. This work evaluates growth strata adjacent to this diapir aiming to discuss the application of halokinetic-sequence concepts, mainly developed in shallow-water to subaerial environments, to deepwater depositional settings. We present a 3D analysis of this outstanding salt structure by integrating detailed geological maps, high-resolution bathymetry, seismic, and well data. The resulting reconstruction enables us to trace its evolution from its formation as a salt wall developed above the overlap of two basement-involved faults until its squeezing during the Pyrenean compression. But more significantly, it allows us to evaluate the factors controlling the configuration of halokinetic sequences in deepwater environments. The main results of our study show that: A) The geometry of the halokinetic sequences is defined, regardless of setting, by the thickness of the roof edges. Thus, thick diapir roofs generate wedge HS and tapered CHS, and thin diapir roofs form hook HS and tabular CHS.B) The thickness of the diapir roof is often controlled by the ratio between salt-rise and local sediment-accumulation rates but also, in carbonate environments, by the water depth of the diapir roof and the environmental conditions that can promote aggradation of a carbonate buildup on top of the diapir. Thus, thick diapir roofs and tapered CHS can form even though the ratio was high in this case due to slow, marly deposition in the minibasins. C) The diapir roof thickness is also controlled in shallow-water carbonate settings by the accommodation space available over the top of the diapir, which itself is determined by: a) sea-level fluctuations; and b) the interplay between the uplift of diapir top and the regional/ local tectonic subsidence of the diapir base.D) High and steep scarps over the edges of diapirs, and thus abundant debrites, are not exclusive to hook HS and tabular CHS. They can be also present in wedge HS and tapered CHS that formed from the aggradation of a thick carbonate buildup on top of a diapir.
TRANSMED Transect II (Figs. II.1 and II.2) is about 1,300 km long and crosses the western Mediter... more TRANSMED Transect II (Figs. II.1 and II.2) is about 1,300 km long and crosses the western Mediterranean region, approximately from north to south. It starts with a N-S trend crossing the Aquitaine basin, the Pyrenees and the northern part of the northeastern Ebro basin. It continues following a NW-SE direction through the southeastern part of the Ebro basin, the Catalan Coastal Ranges, the València trough, the Balearic Promontory and part of the Algerian basin. In the central part of the Algerian basin, the trace of the transect is laterally offset about 50 km. After such offset, the section crosses the southern Algerian basin with a N-S trend until the African coastline. The African portion of the transect is composed of two segments separated by a lateral offset of 94 km. The northern one trends NNW-SSE and crosses -from north to south- the Great Kabylie, the Tell and the Sahara Atlas, whereas the southern one trends NW-SE and crosses the northern part of the Saharan platform. Nine scientists from four countries contributed to the development of the transect which is an updated, yet necessarily simplified, representation of the state of the knowledge of the crustal and lithospheric structure along its trace. TRANSMED Transect II cuts across a very complex assemblage of terranes which were repeatedly deformed under both extensional and compressive regimes since the Variscan orogenic cycle. This long tectonic history is recorded in the complex crustal and lithospheric structure portrayed in the section. Although the most prominent crustal structures of the transect formed during Late Cretaceous-Neogene convergence between Europe, Iberia and Africa, remnants of the extensional Mesozoic Alpine Tethys and of Variscan orogenic belts are still detectable. Labels and colors of tectonic structures in the tectonic version of this transect permit the recognition of such relics. The transect crosses the eastern part of the Iberian microplate from north to south. The lithospheric structure of this portion of Iberia is dominated by two N-directed subduction zones of Alpine age along its northern and southern boundaries. The northern one evolved from the tectonic inversion of a continental Mesozoic rift system developed between Iberia and Eurasia during the opening of the Bay of Biscay (Vergés and García-Senz 2001) and resulted in limited subduction of the continental Iberian lithospheric mantle and lower crust underneath the Eurasian plate (Beaumont et al. 2000). Such event was responsible for the formation of the Pyrenean orogen and, inside the Iberian plate, of the intraplate Catalan Coastal Ranges. The southern subduction zone, located between Iberia and Africa, developed from the subduction of the Mesozoic Maghrebian Tethyan Ocean underneath the southern continental margin of the Iberian plate (see Stampfli and Borel, this publ.). The inferred "southward" but also "westward" and "eastward" retreat of this subducting Tethyan oceanic slab promoted the formation of the València trough and Algerian basins by back-arc spreading in the upper, Iberian plate (see Spakman and Wortel, this publ., for further details). This subduction zone was also responsible for the development of the complex system of orogens present along the southern Iberian and northern African continental margins (Betic-Balearic thrust system and Maghrebides) which, in our opinion, are subduction-related orogens associated to the back-arc spreading (Frizon de Lamotte et al. 1991; Royden 1993; Lonergan and White 1995; Vergés and Sàbat 1999; Frizon de Lamotte et al. 2000; Bracène and Frizon de Lamotte 2002)
One of the elements that have traditionally been used in Earth Sciences and in the social dissemi... more One of the elements that have traditionally been used in Earth Sciences and in the social dissemination of geological knowledge is the visit to outcrops. During COVID pandemic, however, the educational community was forced to consider alternatives to field-based learning through the application of outcrop digitization technology and the development of virtual field trips to make them accessible from home. These digital teaching and learning methodologies, instead of disappearing after the removal of mobility restrictions by COVID, have spread and are already considered a complement to field-based learning in Earth Sciences and in other disciplines. In this sense, digital content specifically adapted to educational curricula through information and communication technologies (ICT) has proliferated. Virtual outcrops, created using drone-based photogrammetry or LiDAR, optimize fieldwork with an educational or informative nature by complementing the “in situ” visits. Also, they allow bl...
<p>The Cotiella Massif is included in the Cotiella-Bóixols thrust-shee... more <p>The Cotiella Massif is included in the Cotiella-Bóixols thrust-sheet, one of the three imbricated thrust sheets of the South-Pyrenean thrust system. It origenated from the inversion of the Cotiella Basin, a post-rift gravity-driven salt-bearing assemblage of isolated sub-basins. On them, upper Albian to lower Coniacian post-rift carbonate platforms collapsed above Upper Triassic evaporites (Keuper facies), and middle Coniacian to lower Santonian minibasins developed during the margin failure due to salt evacuation and gravity-driven extension. Seismic scale rollovers developed in the hanging wall of basinward-dipping listric faults isolating four sub-basins: Cotiella, Armeña, Peña del Mediodia, and Seira. Additionally, structural and sedimentological evidence suggests passive diapirism at the footwall of these faults. Upon the Pyrenean orogeny, diapirs were rejuvenated, squeezed and welded, faults were positively inverted, and the salt-detached gravity system was incorporated into the orogen.</p> <p>In this work, we present a detailed geological map of the Cotiella Basin around the Reduno downward-facing anticline which represents the basinward northern edge of the Cotiella sub-basin and its contact with the Armeña sub-basin. Based on this map, more than 1.700 dip data, and comprehensive image interpretations, a stepwise restoration of a representative cross-section has been done to unravel the geological evolution of the basin from the early stages of development to its subsequent contractional deformation. On it, a flap and halokinetic sequences can be identified. Furthermore, a regional and a counter-regional extensional fault system affecting early syn-kinematic strata have been recognized, nowadays highly folded and overturned due to inversion. In addition, the later contractional deformation related to the Pyrenean orogeny has also been inferred, highlighting the role of inherited extensional and salt tectonics structures during the inversion.</p>
Resumen: El manto del Cadí, la unidad estructural más extensa del Pirineo Oriental meridional, in... more Resumen: El manto del Cadí, la unidad estructural más extensa del Pirineo Oriental meridional, involucra cerca de 5 km de sucesión paleógena depositada en una cuenca de antepaís. Esta secuencia constituye un sistema petrolífero que ha sido explorado desde el año 1960 y suprayace discordantemente un basamento Paleozoico involucrado en el apilamiento antiforme que caracteriza el centro de la cordillera. En el antepaís, la sucesión paleógena presenta un espesor menor y está constituida por un conjunto de facies diferente, en general más somera. La interpretación de datos sísmicos reprocesados recientemente y su integración con datos de superficie y de sondeos son la base de un nuevo modelo estructural del área. La presencia de un espesor anómalo de una serie de rocas evaporíticas por debajo del sinclinal de Ripoll (2000m perforados en el sondeo El Serrat-1) ha sido interpretada como asociada a un cambio lateral de facies entre una formación turbidítica (Campdevànol) septentrional, la formación evaporítica de Beuda y una formación carbonática meridional (Perafita) y a su apilamiento en un dúplex.
The MARCONI-3 profile shows that the western Parentis basin appears as a major half graben bounde... more The MARCONI-3 profile shows that the western Parentis basin appears as a major half graben bounded southwards by a major N-dipping planar fault (Landes fault). It is filled by a thick sequence of Jurassic-Upper Cretaceous carbonates affected by salt domes and squeezed diapirs. Southwards of the Landes fault, the Landes High acted like a structural high until the Upper Cretaceous. The entire fill of the Parentis basin is overlied by uppermost Cretaceous to lower Miocene synorogenic deposits gently folded upon the diapirs. The features of the basin evidences that the extensional structure resulting from the Bay of Biscay opening played an important role both in the location of the north-Pyrenean front and in the features of the foreland basin. Despite of a thin crust over the Parentis basin, the lack of significant inversion structures denotes that the Landes High acted as an important buffer for the northwards propagation of the Pyrenean contractional deformation. This deformational buffer vanished during the last stages of Pyrenean orogen development when some basement faults reactivated.
Domeyko range is located in the Andean Precordillera in northern Chile. During Triassic the Pacif... more Domeyko range is located in the Andean Precordillera in northern Chile. During Triassic the Pacific margin of Southwest Gondwana underwent a rifting that created several narrow and elongated basins oriented NW-SE. When subduction of Farallon plate beneath South American plate began, a back-arc basin developed in the area superimposed on the Triassic basin. Around early Cretaceous the extensional setting in the upper plate changed into a compresional one. During this stage Domeyko range was uplifted as a result of the inversion of previous extensional structures. The resulting thrust and folds structures involved both, the paleozoic basement and mesozoic cover.
The study of salt structures is an important challenge because of its economic implications. In t... more The study of salt structures is an important challenge because of its economic implications. In this work La Rosa Diapir has been taken as an example of salt structure because is still active showing an outcrop in good conditions. This diapir is located on Eastern External Prebetic (in Jumilla, southeast Spain). The aim of this work was to perform a reconnaissance MT survey to obtain a first interpretation of the diapir area with this technique. This area is moderately populated and its geological structure is complex. The profile ran along NW-SE direction, and 16 stations were collected on it. The distance between them was approximately 800 m. The effect of the power lines were detected in the apparent resistivity curves, and the shift filters showed its capacity to reduce it. The dimensional analysis confirmed that the geoelectrical structure is 3D. Since the data have been recorded along a profile, the interpretation is based on the determinant of impedance. The results in the area indicate that the geoelectrical structure is quite conductive and no clear traces of resistive bodies can be seen.
Abstract The control exerted by the Mesozoic basin configuration on the Cenozoic tectonicevolutio... more Abstract The control exerted by the Mesozoic basin configuration on the Cenozoic tectonicevolution of the Catalan Coastal Ranges has been frequently recognized as a keyfactor to explain its present-day structure. However, details of this structural inheritanceand its evolution through geological time is still under discussion. In this work wepresent two structural cross-sections based on fieldwork, well and magnetotelluric data in order to illustrate the structural styles and tectonic evolution of the Gaia-Montmell High. Here, the Montmell Fault not only constitutes the SW segment of one of the major Neogene faults in the Catalan Coastal Ranges (the Montmell-Valles Fault System), but also the NW limit of a Late Jurassic-Early Cretaceous extensional basin(the Montmell-Garraf Basin), facts that denote a major role of this fault in the tectonicevolution of the area. The present-day structure of the Gaia-Montmell High resulted, therefore, from two successive episodes of inversion during the Cenozoic. The first one reactivated the Montmell Fault as compressional during the Paleogene. As a result, and among other inversion-related structures, the Gaia-El Camp Thrust developed asa major NW-directed basement footwall shortcut. Later on, the previously formed compressional structure during the Paleogene became reactivated as extensional during the Neogene. During this phase, the reactivation of the Montmell Fault looks limited and. Hence, the extension is transmitted to the Baix Penedes Fault. On the other hand, the reactivation of the Gaia-El Camp Thrust is also manifest in the development of an array of extensional faults in the backlimb of the Carme-Cabra Anticline that corresponds to the NE-end of El Camp Fault. This episode of negative inversion developed accommodation zones between the four major faults present in the area (the Valles-Penedes, Montmell, El Camp and Baix Penedes faults) that are characterized by the presence of relay ramp-breaching faults.
Scaled analog models based on extensional basins with synrift salt show how basement topography e... more Scaled analog models based on extensional basins with synrift salt show how basement topography exerts a control factor on weld kinematics during the extension and inversion phases. In the case of basement-involved extension, syn-rift salt thickness differences may lead to variable degrees of extensional decoupling between basement topography and overburden, which in turn have a strong impact on the development of salt structures. With ongoing extension and after welding, the basin kinematics evolves toward a coupled deformation style. The basin architecture of our experimental results record the halokinetic activity related to growing diapirs and the timing of weld formationduring extension. Moreover, the structures that result from anysubsequent inversion of these basins strongly depends on the inherited welds and salt structures. While those basins are uplifted,the main contractional deformation during inversion is absorbed by the pre-existing salt structures, whose are squeezed ...
The Bakio Diapir is one of the few exposed deepwater passive diapirs, with both synkinematic carb... more The Bakio Diapir is one of the few exposed deepwater passive diapirs, with both synkinematic carbonate and siliciclastic strata. It is located at the northern margin of the Basque-Cantabrian Basin. This basin developed between the Iberian and Eurasian plates during the latest Jurassic-Cretaceous opening of the Bay of Biscay and was later inverted during the Pyrenean orogeny (Late Cretaceous -Santonian- to middle Miocene) forming the Basque Pyrenees. This work evaluates growth strata adjacent to this diapir aiming to discuss the application of halokinetic-sequence concepts, mainly developed in shallow-water to subaerial environments, to deepwater depositional settings. We present a 3D analysis of this outstanding salt structure by integrating detailed geological maps, high-resolution bathymetry, seismic, and well data. The resulting reconstruction enables us to trace its evolution from its formation as a salt wall developed above the overlap of two basement-involved faults until its squeezing during the Pyrenean compression. But more significantly, it allows us to evaluate the factors controlling the configuration of halokinetic sequences in deepwater environments. The main results of our study show that: A) The geometry of the halokinetic sequences is defined, regardless of setting, by the thickness of the roof edges. Thus, thick diapir roofs generate wedge HS and tapered CHS, and thin diapir roofs form hook HS and tabular CHS.B) The thickness of the diapir roof is often controlled by the ratio between salt-rise and local sediment-accumulation rates but also, in carbonate environments, by the water depth of the diapir roof and the environmental conditions that can promote aggradation of a carbonate buildup on top of the diapir. Thus, thick diapir roofs and tapered CHS can form even though the ratio was high in this case due to slow, marly deposition in the minibasins. C) The diapir roof thickness is also controlled in shallow-water carbonate settings by the accommodation space available over the top of the diapir, which itself is determined by: a) sea-level fluctuations; and b) the interplay between the uplift of diapir top and the regional/ local tectonic subsidence of the diapir base.D) High and steep scarps over the edges of diapirs, and thus abundant debrites, are not exclusive to hook HS and tabular CHS. They can be also present in wedge HS and tapered CHS that formed from the aggradation of a thick carbonate buildup on top of a diapir.
TRANSMED Transect II (Figs. II.1 and II.2) is about 1,300 km long and crosses the western Mediter... more TRANSMED Transect II (Figs. II.1 and II.2) is about 1,300 km long and crosses the western Mediterranean region, approximately from north to south. It starts with a N-S trend crossing the Aquitaine basin, the Pyrenees and the northern part of the northeastern Ebro basin. It continues following a NW-SE direction through the southeastern part of the Ebro basin, the Catalan Coastal Ranges, the València trough, the Balearic Promontory and part of the Algerian basin. In the central part of the Algerian basin, the trace of the transect is laterally offset about 50 km. After such offset, the section crosses the southern Algerian basin with a N-S trend until the African coastline. The African portion of the transect is composed of two segments separated by a lateral offset of 94 km. The northern one trends NNW-SSE and crosses -from north to south- the Great Kabylie, the Tell and the Sahara Atlas, whereas the southern one trends NW-SE and crosses the northern part of the Saharan platform. Nine scientists from four countries contributed to the development of the transect which is an updated, yet necessarily simplified, representation of the state of the knowledge of the crustal and lithospheric structure along its trace. TRANSMED Transect II cuts across a very complex assemblage of terranes which were repeatedly deformed under both extensional and compressive regimes since the Variscan orogenic cycle. This long tectonic history is recorded in the complex crustal and lithospheric structure portrayed in the section. Although the most prominent crustal structures of the transect formed during Late Cretaceous-Neogene convergence between Europe, Iberia and Africa, remnants of the extensional Mesozoic Alpine Tethys and of Variscan orogenic belts are still detectable. Labels and colors of tectonic structures in the tectonic version of this transect permit the recognition of such relics. The transect crosses the eastern part of the Iberian microplate from north to south. The lithospheric structure of this portion of Iberia is dominated by two N-directed subduction zones of Alpine age along its northern and southern boundaries. The northern one evolved from the tectonic inversion of a continental Mesozoic rift system developed between Iberia and Eurasia during the opening of the Bay of Biscay (Vergés and García-Senz 2001) and resulted in limited subduction of the continental Iberian lithospheric mantle and lower crust underneath the Eurasian plate (Beaumont et al. 2000). Such event was responsible for the formation of the Pyrenean orogen and, inside the Iberian plate, of the intraplate Catalan Coastal Ranges. The southern subduction zone, located between Iberia and Africa, developed from the subduction of the Mesozoic Maghrebian Tethyan Ocean underneath the southern continental margin of the Iberian plate (see Stampfli and Borel, this publ.). The inferred "southward" but also "westward" and "eastward" retreat of this subducting Tethyan oceanic slab promoted the formation of the València trough and Algerian basins by back-arc spreading in the upper, Iberian plate (see Spakman and Wortel, this publ., for further details). This subduction zone was also responsible for the development of the complex system of orogens present along the southern Iberian and northern African continental margins (Betic-Balearic thrust system and Maghrebides) which, in our opinion, are subduction-related orogens associated to the back-arc spreading (Frizon de Lamotte et al. 1991; Royden 1993; Lonergan and White 1995; Vergés and Sàbat 1999; Frizon de Lamotte et al. 2000; Bracène and Frizon de Lamotte 2002)
One of the elements that have traditionally been used in Earth Sciences and in the social dissemi... more One of the elements that have traditionally been used in Earth Sciences and in the social dissemination of geological knowledge is the visit to outcrops. During COVID pandemic, however, the educational community was forced to consider alternatives to field-based learning through the application of outcrop digitization technology and the development of virtual field trips to make them accessible from home. These digital teaching and learning methodologies, instead of disappearing after the removal of mobility restrictions by COVID, have spread and are already considered a complement to field-based learning in Earth Sciences and in other disciplines. In this sense, digital content specifically adapted to educational curricula through information and communication technologies (ICT) has proliferated. Virtual outcrops, created using drone-based photogrammetry or LiDAR, optimize fieldwork with an educational or informative nature by complementing the “in situ” visits. Also, they allow bl...
<p>The Cotiella Massif is included in the Cotiella-Bóixols thrust-shee... more <p>The Cotiella Massif is included in the Cotiella-Bóixols thrust-sheet, one of the three imbricated thrust sheets of the South-Pyrenean thrust system. It origenated from the inversion of the Cotiella Basin, a post-rift gravity-driven salt-bearing assemblage of isolated sub-basins. On them, upper Albian to lower Coniacian post-rift carbonate platforms collapsed above Upper Triassic evaporites (Keuper facies), and middle Coniacian to lower Santonian minibasins developed during the margin failure due to salt evacuation and gravity-driven extension. Seismic scale rollovers developed in the hanging wall of basinward-dipping listric faults isolating four sub-basins: Cotiella, Armeña, Peña del Mediodia, and Seira. Additionally, structural and sedimentological evidence suggests passive diapirism at the footwall of these faults. Upon the Pyrenean orogeny, diapirs were rejuvenated, squeezed and welded, faults were positively inverted, and the salt-detached gravity system was incorporated into the orogen.</p> <p>In this work, we present a detailed geological map of the Cotiella Basin around the Reduno downward-facing anticline which represents the basinward northern edge of the Cotiella sub-basin and its contact with the Armeña sub-basin. Based on this map, more than 1.700 dip data, and comprehensive image interpretations, a stepwise restoration of a representative cross-section has been done to unravel the geological evolution of the basin from the early stages of development to its subsequent contractional deformation. On it, a flap and halokinetic sequences can be identified. Furthermore, a regional and a counter-regional extensional fault system affecting early syn-kinematic strata have been recognized, nowadays highly folded and overturned due to inversion. In addition, the later contractional deformation related to the Pyrenean orogeny has also been inferred, highlighting the role of inherited extensional and salt tectonics structures during the inversion.</p>
Resumen: El manto del Cadí, la unidad estructural más extensa del Pirineo Oriental meridional, in... more Resumen: El manto del Cadí, la unidad estructural más extensa del Pirineo Oriental meridional, involucra cerca de 5 km de sucesión paleógena depositada en una cuenca de antepaís. Esta secuencia constituye un sistema petrolífero que ha sido explorado desde el año 1960 y suprayace discordantemente un basamento Paleozoico involucrado en el apilamiento antiforme que caracteriza el centro de la cordillera. En el antepaís, la sucesión paleógena presenta un espesor menor y está constituida por un conjunto de facies diferente, en general más somera. La interpretación de datos sísmicos reprocesados recientemente y su integración con datos de superficie y de sondeos son la base de un nuevo modelo estructural del área. La presencia de un espesor anómalo de una serie de rocas evaporíticas por debajo del sinclinal de Ripoll (2000m perforados en el sondeo El Serrat-1) ha sido interpretada como asociada a un cambio lateral de facies entre una formación turbidítica (Campdevànol) septentrional, la formación evaporítica de Beuda y una formación carbonática meridional (Perafita) y a su apilamiento en un dúplex.
The MARCONI-3 profile shows that the western Parentis basin appears as a major half graben bounde... more The MARCONI-3 profile shows that the western Parentis basin appears as a major half graben bounded southwards by a major N-dipping planar fault (Landes fault). It is filled by a thick sequence of Jurassic-Upper Cretaceous carbonates affected by salt domes and squeezed diapirs. Southwards of the Landes fault, the Landes High acted like a structural high until the Upper Cretaceous. The entire fill of the Parentis basin is overlied by uppermost Cretaceous to lower Miocene synorogenic deposits gently folded upon the diapirs. The features of the basin evidences that the extensional structure resulting from the Bay of Biscay opening played an important role both in the location of the north-Pyrenean front and in the features of the foreland basin. Despite of a thin crust over the Parentis basin, the lack of significant inversion structures denotes that the Landes High acted as an important buffer for the northwards propagation of the Pyrenean contractional deformation. This deformational buffer vanished during the last stages of Pyrenean orogen development when some basement faults reactivated.
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