The Experts below are selected from a list of 2856 Experts worldwide ranked by ideXlab platform
Jean-paul Callot - One of the best experts on this subject based on the ideXlab platform.
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Salt Tectonics in the Sivas Basin (Turkey) - Outstanding seismic analogues
2017Co-Authors: Jean-paul Callot, Jean-claude RingenbachAbstract:The Sivas Basin in Anatolia is likely the world’s finest open-air museum of Salt tectonic structures. It is an elongated Oligo-Miocene basin that developed in an orogenic context. From Late Eocene to Late Miocene Salt deposition, Salt Tectonics and Salt reworking occurred in a north-verging foreland fold-and-thrust belt setting north of the Taurus. The result is an intricate system of Salt ridges, minibasins, Salt sheets and successive canopies. Despite huge difference in content and evolution the Sivas basin provides outstanding outcrops of the classical geometries associated to the development of diapirs, i.e. halokinetic sequences along diapir walls, and associated stratal deformations. The Sivas Basin also presents more exotic structures such as 4-ways closed minibasins, megaflaps (thinned sedimentary sequences pinching out on top of diapirs and overturned during glaciers later development) and evaporites allochtonous sheets. Striking geometric analogies between these outcrops and seismic images from the classic petroleum province controlled by Salt Tectonics will illustrate the extraordinary quality of the Sivas basin as field analogue for the Atlantic Margin and chiefly Angola and the Gulf of Mexico. Some comparisons with analog models under scanner will also be shown.
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Salt Tectonics in the Sivas basin (Turkey): Crossing Salt walls and minibasins
Bulletin de la Société Géologique de France, 2014Co-Authors: Jean-paul Callot, Jean-françois Salel, Charlie Kergaravat, Charlotte Ribes, Cédric Bonnel, Haluk Temiz, André Poisson, Bruno Vrielynck, Jean-claude RingenbachAbstract:The Sivas basin (Turkey) shows pronounced Salt Tectonics activity involving the Oligocene evaporites. Despite the complete exposure of the structures, the tectonic evolution of the basin has been so far misunderstood because it has only been envisioned in a context of thrust Tectonics. The core of the basin, a 35x25 km area, displays rounded minibasins separated by evaporitic walls, and partially covered by remobilized gypsum (either sedimentary or flowage). The minibasins are filled by Mid-Oligocene to Early Miocene elastics (fluvial silts and sandstones), marls, and lacustrine to marine limestones, the thickness of which may reach 4 kilometres. The stratal architecture along evaporite walls records the progressive subsidence of the minibasins, with strong rotation of beds, unconformities and local reworking of evaporites. Within the basin, the sediments show lateral thickness variations and spectacular angular unconformities. The observed geometries show striking similarities with the seismic data from petroleum basins suffering strong Salt tectonism (gulf of Mexico, Precaspian basin, Angolan margin).
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Salt Tectonics in the Sivas basin (Turkey): Crossing Salt walls and minibasins
Bulletin de la Société Géologique de France, 2014Co-Authors: Jean-paul Callot, Jean-françois Salel, Charlie Kergaravat, Charlotte Ribes, Cédric Bonnel, Haluk Temiz, André Poisson, Bruno Vrielynck, Jean-claude RingenbachAbstract:The Sivas basin (Turkey) shows pronounced Salt Tectonics activity involving the Oligocene evaporites. Despite the complete exposure of the structures, the tectonic evolution of the basin has been so far misunderstood because it has only been envisioned in a context of thrust Tectonics. The core of the basin, a 35×25 km area, displays rounded minibasins separated by evaporitic walls, and partially covered by remobilized gypsum (either sedimentary or flowage). The minibasins are filled by Mid-Oligocene to Early Miocene clastics (fluvial silts and sandstones), marls, and lacustrine to marine limestones, the thickness of which may reach 4 kilometres. The stratal architecture along evaporite walls records the progressive subsidence of the minibasins, with strong rotation of beds, unconformities and local reworking of evaporites. Within the basin, the sediments show lateral thickness variations and spectacular angular unconformities. The observed geometries show striking similarities with the seismic data from petroleum basins suffering strong Salt tectonism (gulf of Mexico, Precaspian basin, Angolan margin).
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Salt Tectonics in the Sivas Basin, Turkey: Outstanding seismic analogues from outcrops
First Break, 2013Co-Authors: Jean-claude Ringenbach, Jean-françois Salel, Charlie Kergaravat, Charlotte Ribes, Cédric Bonnel, Jean-paul CallotAbstract:The Sivas Basin in Central Anatolia is possibly the world's finest open-air museum of Salt Tectonics structures. It is an elongated Oligo-Miocene sag basin that developed in an orogenic context above the Neotethys suture zone. A mid-Oligocene quiet period during convergence of the Arabian and Eurasian plates allowed the deposition of a thick sequence of evaporites. Erosion of the Taurus Mountains shed clastic sediments northwards over the evaporitic basin. Sediments and deformation propagated from the south, forming mini-basins and associated evaporite diapirs and walls. Following this quiet period, compression resumed in the early Miocene, enhancing the formation of gypsum overhangs and allochtonous sheets. The Sivas outcrops expose classic Salt Tectonics geometries associated with the development of diapirs: halokinetic sedimentary sequences along diapir walls, welds and evaporite sheets or canopies, minibasins, and overturned minibasin wings (overturned edges of minibasins). These exposures are some of the finest field analogues for classical petroleum provinces controlled by Salt Tectonics such as the Gulf of Mexico and offshore Angola. We illustrate seismic-scale structures and, in the vicinity of the evaporite bodies, interesting analogues for drilled structures where seismic data do not provide an image.
Jean-claude Ringenbach - One of the best experts on this subject based on the ideXlab platform.
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Salt Tectonics in the Sivas Basin (Turkey) - Outstanding seismic analogues
2017Co-Authors: Jean-paul Callot, Jean-claude RingenbachAbstract:The Sivas Basin in Anatolia is likely the world’s finest open-air museum of Salt tectonic structures. It is an elongated Oligo-Miocene basin that developed in an orogenic context. From Late Eocene to Late Miocene Salt deposition, Salt Tectonics and Salt reworking occurred in a north-verging foreland fold-and-thrust belt setting north of the Taurus. The result is an intricate system of Salt ridges, minibasins, Salt sheets and successive canopies. Despite huge difference in content and evolution the Sivas basin provides outstanding outcrops of the classical geometries associated to the development of diapirs, i.e. halokinetic sequences along diapir walls, and associated stratal deformations. The Sivas Basin also presents more exotic structures such as 4-ways closed minibasins, megaflaps (thinned sedimentary sequences pinching out on top of diapirs and overturned during glaciers later development) and evaporites allochtonous sheets. Striking geometric analogies between these outcrops and seismic images from the classic petroleum province controlled by Salt Tectonics will illustrate the extraordinary quality of the Sivas basin as field analogue for the Atlantic Margin and chiefly Angola and the Gulf of Mexico. Some comparisons with analog models under scanner will also be shown.
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Salt Tectonics in the Sivas basin (Turkey): Crossing Salt walls and minibasins
Bulletin de la Société Géologique de France, 2014Co-Authors: Jean-paul Callot, Jean-françois Salel, Charlie Kergaravat, Charlotte Ribes, Cédric Bonnel, Haluk Temiz, André Poisson, Bruno Vrielynck, Jean-claude RingenbachAbstract:The Sivas basin (Turkey) shows pronounced Salt Tectonics activity involving the Oligocene evaporites. Despite the complete exposure of the structures, the tectonic evolution of the basin has been so far misunderstood because it has only been envisioned in a context of thrust Tectonics. The core of the basin, a 35x25 km area, displays rounded minibasins separated by evaporitic walls, and partially covered by remobilized gypsum (either sedimentary or flowage). The minibasins are filled by Mid-Oligocene to Early Miocene elastics (fluvial silts and sandstones), marls, and lacustrine to marine limestones, the thickness of which may reach 4 kilometres. The stratal architecture along evaporite walls records the progressive subsidence of the minibasins, with strong rotation of beds, unconformities and local reworking of evaporites. Within the basin, the sediments show lateral thickness variations and spectacular angular unconformities. The observed geometries show striking similarities with the seismic data from petroleum basins suffering strong Salt tectonism (gulf of Mexico, Precaspian basin, Angolan margin).
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Salt Tectonics in the Sivas basin (Turkey): Crossing Salt walls and minibasins
Bulletin de la Société Géologique de France, 2014Co-Authors: Jean-paul Callot, Jean-françois Salel, Charlie Kergaravat, Charlotte Ribes, Cédric Bonnel, Haluk Temiz, André Poisson, Bruno Vrielynck, Jean-claude RingenbachAbstract:The Sivas basin (Turkey) shows pronounced Salt Tectonics activity involving the Oligocene evaporites. Despite the complete exposure of the structures, the tectonic evolution of the basin has been so far misunderstood because it has only been envisioned in a context of thrust Tectonics. The core of the basin, a 35×25 km area, displays rounded minibasins separated by evaporitic walls, and partially covered by remobilized gypsum (either sedimentary or flowage). The minibasins are filled by Mid-Oligocene to Early Miocene clastics (fluvial silts and sandstones), marls, and lacustrine to marine limestones, the thickness of which may reach 4 kilometres. The stratal architecture along evaporite walls records the progressive subsidence of the minibasins, with strong rotation of beds, unconformities and local reworking of evaporites. Within the basin, the sediments show lateral thickness variations and spectacular angular unconformities. The observed geometries show striking similarities with the seismic data from petroleum basins suffering strong Salt tectonism (gulf of Mexico, Precaspian basin, Angolan margin).
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Salt Tectonics in the Sivas Basin, Turkey: Outstanding seismic analogues from outcrops
First Break, 2013Co-Authors: Jean-claude Ringenbach, Jean-françois Salel, Charlie Kergaravat, Charlotte Ribes, Cédric Bonnel, Jean-paul CallotAbstract:The Sivas Basin in Central Anatolia is possibly the world's finest open-air museum of Salt Tectonics structures. It is an elongated Oligo-Miocene sag basin that developed in an orogenic context above the Neotethys suture zone. A mid-Oligocene quiet period during convergence of the Arabian and Eurasian plates allowed the deposition of a thick sequence of evaporites. Erosion of the Taurus Mountains shed clastic sediments northwards over the evaporitic basin. Sediments and deformation propagated from the south, forming mini-basins and associated evaporite diapirs and walls. Following this quiet period, compression resumed in the early Miocene, enhancing the formation of gypsum overhangs and allochtonous sheets. The Sivas outcrops expose classic Salt Tectonics geometries associated with the development of diapirs: halokinetic sedimentary sequences along diapir walls, welds and evaporite sheets or canopies, minibasins, and overturned minibasin wings (overturned edges of minibasins). These exposures are some of the finest field analogues for classical petroleum provinces controlled by Salt Tectonics such as the Gulf of Mexico and offshore Angola. We illustrate seismic-scale structures and, in the vicinity of the evaporite bodies, interesting analogues for drilled structures where seismic data do not provide an image.
Thibault Duretz - One of the best experts on this subject based on the ideXlab platform.
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Review of Iberia-Eurasia plate-boundary basins: Role of sedimentary burial and Salt Tectonics during rifting and continental breakup
Basin Research, 2021Co-Authors: Nicolas Saspiturry, Riccardo Asti, Yves Lagabrielle, Philippe Razin, Thierry Baudin, Cécile Allanic, Olivier Serrano, Thibault DuretzAbstract:We document the role of sedimentary burial and Salt Tectonics in controlling the deformation style of continental crust during hyperextension. The Iberian-European boundary records a complex history of Cretaceous continental extension, which has led to the development of so-called smooth-slope type basins. Based on the review of the available geological constraints (crustal-balanced cross sections, sedimentary profile evolution, RSCM thermometer, low-temperature thermochronology) and geophysical data (Bouguer anomaly, Moho depth, seismic reflection profiles, and Vp/Vs velocity models) on the Tartas, Arzacq, Cameros, Parentis, Columbrets, Mauléon, Basque-Cantabrian and Internal Metamorphic Zone basins, we shed light on the main characteristics of this type of basin. This synthesis indicates that crustal thinning was influenced by two decoupling horizons: the middle crust and Triassic pre-rift Salt, initially located between the basement and pre-rift sedimentary cover. These two horizons remained active throughout basin formation and were responsible for depth-dependent thinning of the crust and syn-rift Salt Tectonics. We therefore identify several successive deformation phases involving (1) pure shear dominated thinning, (2) simple shear dominated thinning and (3) continental breakup. In the first phase, distributed deformation resulted in the development of a symmetric basin. Field observations indicate that the middle and lower crust were under dominantly ductile conditions at this stage. In the second phase, deformation was localized along a crustal detachment rooted between the crust and the mantle and connecting upwards with Triassic pre-rift Salt. During continental breakup, basin shoulders recorded the occurrence of brittle deformation while the hyperextended domain remained under predominantly ductile thinning. The formation of smooth-slope type extensional basins was intrinsically linked to the combined deposition of thick syn-rift and breakup sequences, and regional Salt Tectonics. They induced significant burial and allowed the continental crust and the pre-rift sequence to deform under high temperature conditions from the rifting to continental breakup stages.
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numerical modelling of cretaceous pyrenean rifting the interaction between mantle exhumation and syn rift Salt Tectonics
Basin Research, 2020Co-Authors: Thibault Duretz, Riccardo Asti, Yves Lagabrielle, Jeanpierre Brun, Anthony Jourdon, Camille Clerc, Benjamin CorreAbstract:The preshortening Cretaceous Pyrenean Rift is an outstanding geological laboratory to investigate the effects of a pre‐rift Salt layer at the sedimentary base on lithospheric rifting. The occurrence of a pre‐rift km‐scale layer of evaporites and shales promoted the activation of syn‐rift Salt Tectonics from the onset of rifting. The pre‐ and syn‐rift sediments are locally affected by high‐temperature metamorphism related to mantle ascent up to shallow depths during rifting. The thermo‐mechanical interaction between decollement along the pre‐existing Salt layer and mantle ascent makes the Cretaceous Pyrenean Rifting drastically different from the type of rifting that shaped most Atlantic‐type passive margins where Salt deposition is syn‐rift and gravity‐driven Salt Tectonics has been postrift. To unravel the dynamic evolution of the Cretaceous Pyrenean Rift, we carried out a set of numerical models of lithosphere‐scale extension, calibrated using the available geological constraints. Models are used to investigate the effects of a km‐scale pre‐rift Salt layer, located at the sedimentary cover base, on the dynamics of rifting. Our results highlight the key role of the decollement layer at cover base that can alone explain both Salt Tectonics deformation style and high‐temperature metamorphism of the pre‐rift and syn‐rift sedimentary cover. On the other hand, in the absence of decollement, our model predicts symmetric necking of the lithosphere devoid of any structure and related thermal regime geologically relevant to the Pyrenean case.
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Numerical modelling of Cretaceous Pyrenean Rifting: The interaction between mantle exhumation and syn‐rift Salt Tectonics
Basin Research, 2020Co-Authors: Thibault Duretz, Riccardo Asti, Yves Lagabrielle, Jeanpierre Brun, Anthony Jourdon, Camille Clerc, Benjamin CorreAbstract:The preshortening Cretaceous Pyrenean Rift is an outstanding geological laboratory to investigate the effects of a pre‐rift Salt layer at the sedimentary base on lithospheric rifting. The occurrence of a pre‐rift km‐scale layer of evaporites and shales promoted the activation of syn‐rift Salt Tectonics from the onset of rifting. The pre‐ and syn‐rift sediments are locally affected by high‐temperature metamorphism related to mantle ascent up to shallow depths during rifting. The thermo‐mechanical interaction between décollement along the pre‐existing Salt layer and mantle ascent makes the Cretaceous Pyrenean Rifting drastically different from the type of rifting that shaped most Atlantic‐type passive margins where Salt deposition is syn‐rift and gravity‐driven Salt Tectonics has been postrift. To unravel the dynamic evolution of the Cretaceous Pyrenean Rift, we carried out a set of numerical models of lithosphere‐scale extension, calibrated using the available geological constraints. Models are used to investigate the effects of a km‐scale pre‐rift Salt layer, located at the sedimentary cover base, on the dynamics of rifting. Our results highlight the key role of the décollement layer at cover base that can alone explain both Salt Tectonics deformation style and high‐temperature metamorphism of the pre‐rift and syn‐rift sedimentary cover. On the other hand, in the absence of décollement, our model predicts symmetric necking of the lithosphere devoid of any structure and related thermal regime geologically relevant to the Pyrenean case.
Jeanpierre Brun - One of the best experts on this subject based on the ideXlab platform.
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numerical modelling of cretaceous pyrenean rifting the interaction between mantle exhumation and syn rift Salt Tectonics
Basin Research, 2020Co-Authors: Thibault Duretz, Riccardo Asti, Yves Lagabrielle, Jeanpierre Brun, Anthony Jourdon, Camille Clerc, Benjamin CorreAbstract:The preshortening Cretaceous Pyrenean Rift is an outstanding geological laboratory to investigate the effects of a pre‐rift Salt layer at the sedimentary base on lithospheric rifting. The occurrence of a pre‐rift km‐scale layer of evaporites and shales promoted the activation of syn‐rift Salt Tectonics from the onset of rifting. The pre‐ and syn‐rift sediments are locally affected by high‐temperature metamorphism related to mantle ascent up to shallow depths during rifting. The thermo‐mechanical interaction between decollement along the pre‐existing Salt layer and mantle ascent makes the Cretaceous Pyrenean Rifting drastically different from the type of rifting that shaped most Atlantic‐type passive margins where Salt deposition is syn‐rift and gravity‐driven Salt Tectonics has been postrift. To unravel the dynamic evolution of the Cretaceous Pyrenean Rift, we carried out a set of numerical models of lithosphere‐scale extension, calibrated using the available geological constraints. Models are used to investigate the effects of a km‐scale pre‐rift Salt layer, located at the sedimentary cover base, on the dynamics of rifting. Our results highlight the key role of the decollement layer at cover base that can alone explain both Salt Tectonics deformation style and high‐temperature metamorphism of the pre‐rift and syn‐rift sedimentary cover. On the other hand, in the absence of decollement, our model predicts symmetric necking of the lithosphere devoid of any structure and related thermal regime geologically relevant to the Pyrenean case.
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Numerical modelling of Cretaceous Pyrenean Rifting: The interaction between mantle exhumation and syn‐rift Salt Tectonics
Basin Research, 2020Co-Authors: Thibault Duretz, Riccardo Asti, Yves Lagabrielle, Jeanpierre Brun, Anthony Jourdon, Camille Clerc, Benjamin CorreAbstract:The preshortening Cretaceous Pyrenean Rift is an outstanding geological laboratory to investigate the effects of a pre‐rift Salt layer at the sedimentary base on lithospheric rifting. The occurrence of a pre‐rift km‐scale layer of evaporites and shales promoted the activation of syn‐rift Salt Tectonics from the onset of rifting. The pre‐ and syn‐rift sediments are locally affected by high‐temperature metamorphism related to mantle ascent up to shallow depths during rifting. The thermo‐mechanical interaction between décollement along the pre‐existing Salt layer and mantle ascent makes the Cretaceous Pyrenean Rifting drastically different from the type of rifting that shaped most Atlantic‐type passive margins where Salt deposition is syn‐rift and gravity‐driven Salt Tectonics has been postrift. To unravel the dynamic evolution of the Cretaceous Pyrenean Rift, we carried out a set of numerical models of lithosphere‐scale extension, calibrated using the available geological constraints. Models are used to investigate the effects of a km‐scale pre‐rift Salt layer, located at the sedimentary cover base, on the dynamics of rifting. Our results highlight the key role of the décollement layer at cover base that can alone explain both Salt Tectonics deformation style and high‐temperature metamorphism of the pre‐rift and syn‐rift sedimentary cover. On the other hand, in the absence of décollement, our model predicts symmetric necking of the lithosphere devoid of any structure and related thermal regime geologically relevant to the Pyrenean case.
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Salt Tectonics at passive margins: Geology versus models. Reply
Marine and Petroleum Geology, 2012Co-Authors: Jeanpierre Brun, Xavier FortAbstract:Rowan et al. (2012) vehemently argue that Salt Tectonics is entirely driven by differential sedimentary loading and refute all the results of our work (Brun and Fort, 2011) showing that Salt Tectonics on passive margins is dominated by gliding, which we referred to in our paper as "dominant gliding"; in other words the deformation is controlled by Salt flowing down the regional dip of these margins. We point out that "pure spreading" would be driven by differential sedimentary loading only if margins could remain strictly horizontal (i.e. not tilted), whereas "dominant gliding", which combines spreading and gliding, affects sedimentary successions above Salt layers on passive margins as soon as these are titled. Our work shows that the fundamental dynamic difference between the two processes is that in "pure spreading" Salt resists deformation whereas in "dominant gliding" Salt drives deformation. In "dominant gliding", even in absence of sediments, Salt flows down dip with a component of spreading, demonstrating that differential sedimentary loading is not a necessary condition of Salt Tectonics and that spreading - i.e. layer parallel stretching- does not require sedimentation to occur. Rowan et al. (2012) put forward arguments, related to thrust mechanics and deduced from some "pure spreading" sand and silicon box models, to backup their claims about "pure spreading" but none of them is applicable to Salt basins at margin-scale. The objections made by Rowan et al. (2012) about shelf break migration and slope deformation in the Gulf of Mexico are not substantiated nor justified by verifiable and validated data. Using an adequately scaled laboratory sand-silicone box experiment, in which sedimentary progradation is oblique to silicone (Salt) flow, we show that transfer zones develop with directions close to silicone (Salt) flow and define patterns directly comparable to those observed in the northern Gulf of Mexico. This paper documents the results of a review of all the arguments and statements contradicting the results of our work put forward in Rowan et al. (2012), and suggests that none of them is valid.
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Salt Tectonics at passive margins: Geology versus models – Reply
Marine and Petroleum Geology, 2012Co-Authors: Jeanpierre Brun, Xavier FortAbstract:International audienceRowan et al. (2012) vehemently argue that Salt Tectonics is entirely driven by differential sedimentary loading and refute all the results of our work (Brun and Fort, 2011) showing that Salt Tectonics on passive margins is dominated by gliding, which we referred to in our paper as "dominant gliding"; in other words the deformation is controlled by Salt flowing down the regional dip of these margins. We point out that "pure spreading" would be driven by differential sedimentary loading only if margins could remain strictly horizontal (i.e. not tilted), whereas "dominant gliding", which combines spreading and gliding, affects sedimentary successions above Salt layers on passive margins as soon as these are titled. Our work shows that the fundamental dynamic difference between the two processes is that in "pure spreading" Salt resists deformation whereas in "dominant gliding" Salt drives deformation. In "dominant gliding", even in absence of sediments, Salt flows down dip with a component of spreading, demonstrating that differential sedimentary loading is not a necessary condition of Salt Tectonics and that spreading - i.e. layer parallel stretching- does not require sedimentation to occur. Rowan et al. (2012) put forward arguments, related to thrust mechanics and deduced from some "pure spreading" sand and silicon box models, to backup their claims about "pure spreading" but none of them is applicable to Salt basins at margin-scale. The objections made by Rowan et al. (2012) about shelf break migration and slope deformation in the Gulf of Mexico are not substantiated nor justified by verifiable and validated data. Using an adequately scaled laboratory sand-silicone box experiment, in which sedimentary progradation is oblique to silicone (Salt) flow, we show that transfer zones develop with directions close to silicone (Salt) flow and define patterns directly comparable to those observed in the northern Gulf of Mexico. This paper documents the results of a review of all the arguments and statements contradicting the results of our work put forward in Rowan et al. (2012), and suggests that none of them is valid
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Salt Tectonics at passive margins: Geology versus models
Marine and Petroleum Geology, 2011Co-Authors: Jeanpierre Brun, Xavier FortAbstract:Salt Tectonics at passive margins is currently interpreted as a gravity-driven process but according to two different types of models: i) pure spreading only driven by differential sedimentary loading and ii) dominant gliding primarily due to margin tilt (slope instability). A comparative analysis of pure spreading and pure spreading is made using simple mechanics as well as available laboratory experiments and numerical models that consider Salt tectonic processes at the whole basin scale. To be effective, pure spreading driven by sedimentary loading requires large differential overburden thicknesses and therefore significant water depths, high sediment density, low frictional angles of the sediments (high fluid pore pressure) and a seaward free boundary of the Salt basin (Salt not covered by sediments). Dominant gliding does not require any specific condition to be effective apart from the dip on the upper surface of the Salt. It can occur for margin tilt angles lower than 1° for basin widths in the range of 200-600 km and initial sedimentary cover thickness up to 1 km, even in the absence of abnormal fluid pressure. In pure spreading, Salt resists and sediments drive whereas in dominant gliding both Salt and sediments drive. In pure spreading, extension is located inside the prograding sedimentary wedge and contraction at the tip. Both extension and contraction migrate seaward with the sedimentary progradation. Migration of the deformation can create an extensional inversion of previously contractional structures. In pure spreading, extension is located updip and contraction downdip. Extension migrates downdip and contraction updip. Migration of the deformation leads to a contractional inversion of previously extensional structures (e.g. squeezed diapirs). Mechanical analysis and modelling, either analogue or numerical, and comparison with margin-scale examples, such as the south Atlantic margins or northern Gulf of Mexico, indicate that Salt Tectonics at passive margins is dominated by dominant gliding down the margin dip. On the contrary, Salt Tectonics driven only by differential sedimentary loading is a process difficult to reconcile with geological evidence.
Benjamin Corre - One of the best experts on this subject based on the ideXlab platform.
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numerical modelling of cretaceous pyrenean rifting the interaction between mantle exhumation and syn rift Salt Tectonics
Basin Research, 2020Co-Authors: Thibault Duretz, Riccardo Asti, Yves Lagabrielle, Jeanpierre Brun, Anthony Jourdon, Camille Clerc, Benjamin CorreAbstract:The preshortening Cretaceous Pyrenean Rift is an outstanding geological laboratory to investigate the effects of a pre‐rift Salt layer at the sedimentary base on lithospheric rifting. The occurrence of a pre‐rift km‐scale layer of evaporites and shales promoted the activation of syn‐rift Salt Tectonics from the onset of rifting. The pre‐ and syn‐rift sediments are locally affected by high‐temperature metamorphism related to mantle ascent up to shallow depths during rifting. The thermo‐mechanical interaction between decollement along the pre‐existing Salt layer and mantle ascent makes the Cretaceous Pyrenean Rifting drastically different from the type of rifting that shaped most Atlantic‐type passive margins where Salt deposition is syn‐rift and gravity‐driven Salt Tectonics has been postrift. To unravel the dynamic evolution of the Cretaceous Pyrenean Rift, we carried out a set of numerical models of lithosphere‐scale extension, calibrated using the available geological constraints. Models are used to investigate the effects of a km‐scale pre‐rift Salt layer, located at the sedimentary cover base, on the dynamics of rifting. Our results highlight the key role of the decollement layer at cover base that can alone explain both Salt Tectonics deformation style and high‐temperature metamorphism of the pre‐rift and syn‐rift sedimentary cover. On the other hand, in the absence of decollement, our model predicts symmetric necking of the lithosphere devoid of any structure and related thermal regime geologically relevant to the Pyrenean case.
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Numerical modelling of Cretaceous Pyrenean Rifting: The interaction between mantle exhumation and syn‐rift Salt Tectonics
Basin Research, 2020Co-Authors: Thibault Duretz, Riccardo Asti, Yves Lagabrielle, Jeanpierre Brun, Anthony Jourdon, Camille Clerc, Benjamin CorreAbstract:The preshortening Cretaceous Pyrenean Rift is an outstanding geological laboratory to investigate the effects of a pre‐rift Salt layer at the sedimentary base on lithospheric rifting. The occurrence of a pre‐rift km‐scale layer of evaporites and shales promoted the activation of syn‐rift Salt Tectonics from the onset of rifting. The pre‐ and syn‐rift sediments are locally affected by high‐temperature metamorphism related to mantle ascent up to shallow depths during rifting. The thermo‐mechanical interaction between décollement along the pre‐existing Salt layer and mantle ascent makes the Cretaceous Pyrenean Rifting drastically different from the type of rifting that shaped most Atlantic‐type passive margins where Salt deposition is syn‐rift and gravity‐driven Salt Tectonics has been postrift. To unravel the dynamic evolution of the Cretaceous Pyrenean Rift, we carried out a set of numerical models of lithosphere‐scale extension, calibrated using the available geological constraints. Models are used to investigate the effects of a km‐scale pre‐rift Salt layer, located at the sedimentary cover base, on the dynamics of rifting. Our results highlight the key role of the décollement layer at cover base that can alone explain both Salt Tectonics deformation style and high‐temperature metamorphism of the pre‐rift and syn‐rift sedimentary cover. On the other hand, in the absence of décollement, our model predicts symmetric necking of the lithosphere devoid of any structure and related thermal regime geologically relevant to the Pyrenean case.
