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Tomas Villamil - One of the best experts on this subject based on the ideXlab platform.
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campanian miocene tectonostratigraphy depocenter evolution and basin development of colombia and western venezuela
Palaeogeography Palaeoclimatology Palaeoecology, 1999Co-Authors: Tomas VillamilAbstract:Abstract The position of the central axis of deposition over Colombian and Venezuelan continental crust has varied markedly through time. The axis migrated from west to east from Late Cretaceous to Oligocene but at times, secondary drainage divides were established by local uplift events. In Oligocene times with initial inversion of the Eastern Cordillera the central axis of deposition was divided into two main axes, the proto-Magdalena and the proto-Orinoco systems. The west to east migration of the central axis of deposition had a tectonic origin and it occurred in combination with tectonically driven changes in accommodation space. Depocenter evolution can be divided as follows. (1) The axis of the Campanian and early Maastrichtian depocenter was located few km east of the present position of the Central Cordillera of Colombia; it migrated east with gradual uplift of the Central Cordillera. (2) The central axis of late Maastrichtian deposition is positioned approximately over the present-day western foothills of the Eastern Cordillera, possibly crosses the Eastern Cordillera over the Santander Massif and continues into the Maracaibo Lake in western Venezuela. Accommodation space decreased from Campanian to Maastrichtian times. In Cretaceous–Tertiary boundary times parts of the eastern margin of the Eastern Cordillera were uplifted by an initial phase of inversion of deeply rooted Jurassic and Early Cretaceous normal faults. (3) In Paleocene times the central axis of deposition was located along the spine of the Eastern Cordillera and extended into the Maracaibo Basin, and accommodation space continued to decrease. (4) In latest Paleocene times the central axis of deposition shifted to eastern regions of the Eastern Cordillera and accommodation space decreased. (5) The Early Eocene central axis of deposition was located along the present-day eastern foothills of the Eastern Cordillera; accommodation space continued to decrease and the regional Middle Eocene unconformity began to develop. In Middle Eocene times a regional unconformity developed, marking the climax of the pre-Andean Orogeny. Deposition during these times was dominant in the Maracaibo Basin area where large amounts of sediment derived from vast exposed areas accumulated. (6) The Late Eocene central axis of deposition was confined to the present position of the Llanos foothills. Late Eocene deposition reflects a regional increase in accommodation space. In Oligocene times the initial uplift of the Eastern Cordillera divided the main depocenter into two central axes. Accommodation space diminished in uplifted regions but continued to increase in the depocenters allowing sporadic marine ingressions into the present position of the Llanos foothills. As uplift of the Eastern Cordillera continued, the eastern depocenter axis (proto-Orinoco) migrated east and the western depocenter axis (proto-Magdalena) migrated west. This process continued through the rest of the Cenozoic.
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Campanian–Miocene tectonostratigraphy, depocenter evolution and basin development of Colombia and western Venezuela
Palaeogeography Palaeoclimatology Palaeoecology, 1999Co-Authors: Tomas VillamilAbstract:Abstract The position of the central axis of deposition over Colombian and Venezuelan continental crust has varied markedly through time. The axis migrated from west to east from Late Cretaceous to Oligocene but at times, secondary drainage divides were established by local uplift events. In Oligocene times with initial inversion of the Eastern Cordillera the central axis of deposition was divided into two main axes, the proto-Magdalena and the proto-Orinoco systems. The west to east migration of the central axis of deposition had a tectonic origin and it occurred in combination with tectonically driven changes in accommodation space. Depocenter evolution can be divided as follows. (1) The axis of the Campanian and early Maastrichtian depocenter was located few km east of the present position of the Central Cordillera of Colombia; it migrated east with gradual uplift of the Central Cordillera. (2) The central axis of late Maastrichtian deposition is positioned approximately over the present-day western foothills of the Eastern Cordillera, possibly crosses the Eastern Cordillera over the Santander Massif and continues into the Maracaibo Lake in western Venezuela. Accommodation space decreased from Campanian to Maastrichtian times. In Cretaceous–Tertiary boundary times parts of the eastern margin of the Eastern Cordillera were uplifted by an initial phase of inversion of deeply rooted Jurassic and Early Cretaceous normal faults. (3) In Paleocene times the central axis of deposition was located along the spine of the Eastern Cordillera and extended into the Maracaibo Basin, and accommodation space continued to decrease. (4) In latest Paleocene times the central axis of deposition shifted to eastern regions of the Eastern Cordillera and accommodation space decreased. (5) The Early Eocene central axis of deposition was located along the present-day eastern foothills of the Eastern Cordillera; accommodation space continued to decrease and the regional Middle Eocene unconformity began to develop. In Middle Eocene times a regional unconformity developed, marking the climax of the pre-Andean Orogeny. Deposition during these times was dominant in the Maracaibo Basin area where large amounts of sediment derived from vast exposed areas accumulated. (6) The Late Eocene central axis of deposition was confined to the present position of the Llanos foothills. Late Eocene deposition reflects a regional increase in accommodation space. In Oligocene times the initial uplift of the Eastern Cordillera divided the main depocenter into two central axes. Accommodation space diminished in uplifted regions but continued to increase in the depocenters allowing sporadic marine ingressions into the present position of the Llanos foothills. As uplift of the Eastern Cordillera continued, the eastern depocenter axis (proto-Orinoco) migrated east and the western depocenter axis (proto-Magdalena) migrated west. This process continued through the rest of the Cenozoic.
Le C Corre - One of the best experts on this subject based on the ideXlab platform.
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cenozoic crustal thickening wrenching and rifting in the foothills of the southernmost andes
Tectonophysics, 2000Co-Authors: Marc Diraison, Eduardo A Rossello, Peter R. Cobbold, Denis Gapais, Le C CorreAbstract:Abstract The southernmost Andes form an orocline, between the Patagonian Cordillera, trending N–S, and the Fueguian Cordilleras, trending E–W. On the foreland side is the Magellan Basin. The area has a history of Paleozoic compression, Triassic to Early Cretaceous rifting and Late Cretaceous to Quaternary compression, in response to changing plate tectonics. Major structures of Late Cretaceous and Cenozoic age vary along the strike. In the Patagonian Cordillera and foothills, folds and thrusts trend NNW, slightly oblique to the orogen, whereas strike–slip faults are parallel to the orogen and right-lateral. In the Fueguian Cordilleras and foothills, folds and thrusts trend ESE, slightly oblique to the orogen, whereas strike–slip faults are parallel to the orogen and left-lateral. In the axial zone of the Magellan Basin, folds and thrusts are parallel to the orogen and rifts are sub-perpendicular to it. To a first approximation, the pattern of structures has mirror symmetry about the axis of the Magellan Basin. In detail, however, wrenching appears to be more prevalent in the Fueguian Cordillera and foothills, than it is in the Patagonian Cordillera and foothills. Minor faults of Cenozoic age are common in the foothills. From a kinematic analysis of fault–slip data: (1) shortening and stretching directions are mostly sub-horizontal; (2) shortening directions vary in trend, from ENE in the Patagonian foothills, to NE in the Fueguian foothills; and (3) stretching directions are sub-parallel to traces of major thrusts. In the Fueguian Cordillera and foothills, strike–slip faulting is prevalent; in the Patagonian foothills, crustal thickening is prevalent over strike–slip faulting. The kinematics reflect a combination of thrusting and wrenching and they are consistent with the major structures. To investigate the origin of the Cenozoic structures, we used analogue models on a fully lithospheric scale, where an oceanic plate subducted beneath a continental corner. The corner was an area of transition, from frontal subduction, to transcurrent motion. The boundary conditions may not have been fully realistic, but the experiments did account for the major elements of the structural pattern in southernmost South America, including rifts that are perpendicular to the orogen and counterclockwise block rotations.
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cenozoic crustal thickening wrenching and rifting in the foothills of the southernmost andes
Tectonophysics, 2000Co-Authors: Marc Diraison, Eduardo A Rossello, Peter R. Cobbold, Denis Gapais, Le C CorreAbstract:Abstract The southernmost Andes form an orocline, between the Patagonian Cordillera, trending N–S, and the Fueguian Cordilleras, trending E–W. On the foreland side is the Magellan Basin. The area has a history of Paleozoic compression, Triassic to Early Cretaceous rifting and Late Cretaceous to Quaternary compression, in response to changing plate tectonics. Major structures of Late Cretaceous and Cenozoic age vary along the strike. In the Patagonian Cordillera and foothills, folds and thrusts trend NNW, slightly oblique to the orogen, whereas strike–slip faults are parallel to the orogen and right-lateral. In the Fueguian Cordilleras and foothills, folds and thrusts trend ESE, slightly oblique to the orogen, whereas strike–slip faults are parallel to the orogen and left-lateral. In the axial zone of the Magellan Basin, folds and thrusts are parallel to the orogen and rifts are sub-perpendicular to it. To a first approximation, the pattern of structures has mirror symmetry about the axis of the Magellan Basin. In detail, however, wrenching appears to be more prevalent in the Fueguian Cordillera and foothills, than it is in the Patagonian Cordillera and foothills. Minor faults of Cenozoic age are common in the foothills. From a kinematic analysis of fault–slip data: (1) shortening and stretching directions are mostly sub-horizontal; (2) shortening directions vary in trend, from ENE in the Patagonian foothills, to NE in the Fueguian foothills; and (3) stretching directions are sub-parallel to traces of major thrusts. In the Fueguian Cordillera and foothills, strike–slip faulting is prevalent; in the Patagonian foothills, crustal thickening is prevalent over strike–slip faulting. The kinematics reflect a combination of thrusting and wrenching and they are consistent with the major structures. To investigate the origin of the Cenozoic structures, we used analogue models on a fully lithospheric scale, where an oceanic plate subducted beneath a continental corner. The corner was an area of transition, from frontal subduction, to transcurrent motion. The boundary conditions may not have been fully realistic, but the experiments did account for the major elements of the structural pattern in southernmost South America, including rifts that are perpendicular to the orogen and counterclockwise block rotations.
Robert Buchwaldt - One of the best experts on this subject based on the ideXlab platform.
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age and provenance of a paleoproterozoic to devonian canadian Cordilleran sequence of metasedimentary rocks thor odin dome southeastern british columbia
Geological Society of America Bulletin, 2014Co-Authors: Yvette D. Kuiper, Caroline D. Shields, Michael Tubrett, Venessa Bennett, Robert BuchwaldtAbstract:We present a U-Pb detrital zircon age and provenance study of a sequence of metasedimentary rocks in the northwestern Thor–Odin high-grade gneiss dome within the Omineca crystalline belt of the Canadian Cordillera. Despite strong overprint by deformation and metamorphism, we successfully analyzed the age and provenance of six samples collected at various structural levels, using U-Pb detrital zircon laser-ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis. The Thor–Odin dome consists of Paleoproterozoic basement and a metasedimentary cover sequence of previously unknown age and tectonic significance. Our results indicate that the oldest units of this sequence may be Paleoproterozoic, and some of the oldest known metasedimentary rocks in the Canadian Cordillera, originally deposited on top of Laurentian basement rocks. The youngest rocks are Devonian and deposited shortly before the onset of widespread Late Devonian to early Mississippian igneous activity in the Selkirk Domain or Kootenay arc. The cover sequence of the Thor–Odin dome thus preserves some of both the oldest and the youngest (meta)sedimentary rocks deposited between the formation of supercontinent Columbia and the onset of igneous activity and convergence that marked the beginning of Cordilleran deformation and metamorphism. Parts of as many as ∼1.4 b.y. of sedimentary history are preserved in the Thor–Odin dome, implying that much information on the sedimentary history of the Canadian Cordillera may be hidden in other Cordilleran gneiss domes.
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Age and provenance of a Paleoproterozoic to Devonian Canadian Cordilleran sequence of metasedimentary rocks, Thor–Odin dome, southeastern British Columbia
Geological Society of America Bulletin, 2014Co-Authors: Yvette D. Kuiper, Caroline D. Shields, Michael Tubrett, Venessa Bennett, Robert BuchwaldtAbstract:We present a U-Pb detrital zircon age and provenance study of a sequence of metasedimentary rocks in the northwestern Thor–Odin high-grade gneiss dome within the Omineca crystalline belt of the Canadian Cordillera. Despite strong overprint by deformation and metamorphism, we successfully analyzed the age and provenance of six samples collected at various structural levels, using U-Pb detrital zircon laser-ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) analysis. The Thor–Odin dome consists of Paleoproterozoic basement and a metasedimentary cover sequence of previously unknown age and tectonic significance. Our results indicate that the oldest units of this sequence may be Paleoproterozoic, and some of the oldest known metasedimentary rocks in the Canadian Cordillera, originally deposited on top of Laurentian basement rocks. The youngest rocks are Devonian and deposited shortly before the onset of widespread Late Devonian to early Mississippian igneous activity in the Selkirk Domain or Kootenay arc. The cover sequence of the Thor–Odin dome thus preserves some of both the oldest and the youngest (meta)sedimentary rocks deposited between the formation of supercontinent Columbia and the onset of igneous activity and convergence that marked the beginning of Cordilleran deformation and metamorphism. Parts of as many as ∼1.4 b.y. of sedimentary history are preserved in the Thor–Odin dome, implying that much information on the sedimentary history of the Canadian Cordillera may be hidden in other Cordilleran gneiss domes.
Marc Diraison - One of the best experts on this subject based on the ideXlab platform.
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cenozoic crustal thickening wrenching and rifting in the foothills of the southernmost andes
Tectonophysics, 2000Co-Authors: Marc Diraison, Eduardo A Rossello, Peter R. Cobbold, Denis Gapais, Le C CorreAbstract:Abstract The southernmost Andes form an orocline, between the Patagonian Cordillera, trending N–S, and the Fueguian Cordilleras, trending E–W. On the foreland side is the Magellan Basin. The area has a history of Paleozoic compression, Triassic to Early Cretaceous rifting and Late Cretaceous to Quaternary compression, in response to changing plate tectonics. Major structures of Late Cretaceous and Cenozoic age vary along the strike. In the Patagonian Cordillera and foothills, folds and thrusts trend NNW, slightly oblique to the orogen, whereas strike–slip faults are parallel to the orogen and right-lateral. In the Fueguian Cordilleras and foothills, folds and thrusts trend ESE, slightly oblique to the orogen, whereas strike–slip faults are parallel to the orogen and left-lateral. In the axial zone of the Magellan Basin, folds and thrusts are parallel to the orogen and rifts are sub-perpendicular to it. To a first approximation, the pattern of structures has mirror symmetry about the axis of the Magellan Basin. In detail, however, wrenching appears to be more prevalent in the Fueguian Cordillera and foothills, than it is in the Patagonian Cordillera and foothills. Minor faults of Cenozoic age are common in the foothills. From a kinematic analysis of fault–slip data: (1) shortening and stretching directions are mostly sub-horizontal; (2) shortening directions vary in trend, from ENE in the Patagonian foothills, to NE in the Fueguian foothills; and (3) stretching directions are sub-parallel to traces of major thrusts. In the Fueguian Cordillera and foothills, strike–slip faulting is prevalent; in the Patagonian foothills, crustal thickening is prevalent over strike–slip faulting. The kinematics reflect a combination of thrusting and wrenching and they are consistent with the major structures. To investigate the origin of the Cenozoic structures, we used analogue models on a fully lithospheric scale, where an oceanic plate subducted beneath a continental corner. The corner was an area of transition, from frontal subduction, to transcurrent motion. The boundary conditions may not have been fully realistic, but the experiments did account for the major elements of the structural pattern in southernmost South America, including rifts that are perpendicular to the orogen and counterclockwise block rotations.
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cenozoic crustal thickening wrenching and rifting in the foothills of the southernmost andes
Tectonophysics, 2000Co-Authors: Marc Diraison, Eduardo A Rossello, Peter R. Cobbold, Denis Gapais, Le C CorreAbstract:Abstract The southernmost Andes form an orocline, between the Patagonian Cordillera, trending N–S, and the Fueguian Cordilleras, trending E–W. On the foreland side is the Magellan Basin. The area has a history of Paleozoic compression, Triassic to Early Cretaceous rifting and Late Cretaceous to Quaternary compression, in response to changing plate tectonics. Major structures of Late Cretaceous and Cenozoic age vary along the strike. In the Patagonian Cordillera and foothills, folds and thrusts trend NNW, slightly oblique to the orogen, whereas strike–slip faults are parallel to the orogen and right-lateral. In the Fueguian Cordilleras and foothills, folds and thrusts trend ESE, slightly oblique to the orogen, whereas strike–slip faults are parallel to the orogen and left-lateral. In the axial zone of the Magellan Basin, folds and thrusts are parallel to the orogen and rifts are sub-perpendicular to it. To a first approximation, the pattern of structures has mirror symmetry about the axis of the Magellan Basin. In detail, however, wrenching appears to be more prevalent in the Fueguian Cordillera and foothills, than it is in the Patagonian Cordillera and foothills. Minor faults of Cenozoic age are common in the foothills. From a kinematic analysis of fault–slip data: (1) shortening and stretching directions are mostly sub-horizontal; (2) shortening directions vary in trend, from ENE in the Patagonian foothills, to NE in the Fueguian foothills; and (3) stretching directions are sub-parallel to traces of major thrusts. In the Fueguian Cordillera and foothills, strike–slip faulting is prevalent; in the Patagonian foothills, crustal thickening is prevalent over strike–slip faulting. The kinematics reflect a combination of thrusting and wrenching and they are consistent with the major structures. To investigate the origin of the Cenozoic structures, we used analogue models on a fully lithospheric scale, where an oceanic plate subducted beneath a continental corner. The corner was an area of transition, from frontal subduction, to transcurrent motion. The boundary conditions may not have been fully realistic, but the experiments did account for the major elements of the structural pattern in southernmost South America, including rifts that are perpendicular to the orogen and counterclockwise block rotations.
Audrey Margirier - One of the best experts on this subject based on the ideXlab platform.
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Role of erosion and isostasy in the Cordillera Blanca uplift: Insights from landscape evolution modeling (northern Peru, Andes)
Tectonophysics, 2018Co-Authors: Audrey Margirier, Xavier Robert, Jean Braun, Laurence AudinAbstract:Abstract The processes driving uplift and exhumation of the highest Peruvian peaks (the Cordillera Blanca) are not well understood. Uplift and exhumation seem closely linked to the formation and movement on the Cordillera Blanca normal fault (CBNF) that delimits and shapes the western flank of the Cordillera Blanca. Several models have been proposed to explain the presence of this major normal fault in a compressional setting, but the CBNF and the Cordillera Blanca recent rapid uplift remain enigmatic. Whereas the Cordillera Blanca morphology demonstrates important erosion and thus a significant mass of rocks removal, the impact of erosion and isostasy on the evolution of the Cordillera Blanca uplift rates has never been explored. We address the role of erosion and associated flexural rebound in the uplift and exhumation of the Cordillera Blanca with numerical modeling of landscape evolution. We perform inversions of the broad features of the present-day topography, total exhumation and thermochronological data using a landscape evolution model (FastScape) to provide constraints on the erosion efficiency factor, the uplift rate and the temperature gradient. Our results evidence the not negligible contribution of erosion and associated flexural rebound to the uplift of the Cordillera Blanca and allow us to question the models previously proposed for the formation of the CBNF.
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time and mode of exhumation of the Cordillera blanca batholith peruvian andes
Journal of Geophysical Research, 2016Co-Authors: Audrey Margirier, Frederic Herman, Laurence Audin, Xavier Robert, Jerome Ganne, Stephane SchwartzAbstract:The Cordillera Blanca batholith (12–5 Myr) forms the highest Peruvian summits and builds the footwall of the Cordillera Blanca normal fault (CBNF). Even if several models have been proposed, the processes driving both the exhumation of the Cordillera Blanca and extensional deformation along the CBNF are still debated. Here we quantify the emplacement depth and exhumation of the batholith of the northern Peru arc from the late Miocene to present. Based on a compilation of crystallization ages and new thermobarometry data in the Cordillera Blanca batholith, we propose that the batholith was emplaced at a depth of ~3 km in successive sills from 14 to 5 Ma. By contrast, the younger rocks exposed at the surface were emplaced the deepest (i.e., ~6 km) and are located close to the CBNF, suggesting post 5 Ma tilting. Furthermore, a formal inversion of the thermochronologic data indicates an increase of the exhumation rates in the Cordillera Blanca during the Quaternary. The higher predicted exhumation rates correlate with areas of high relief, both in the northern and central part of the Cordillera Blanca, suggesting that Quaternary valley carving by glaciations have a significant impact on the latest stage of the Cordillera Blanca exhumation (2–0 Ma).
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Slab flattening, magmatism, and surface uplift in the Cordillera Occidental (northern Peru)
Geology, 2015Co-Authors: Audrey Margirier, Laurence Audin, Xavier Robert, C.e Gautheron, Matthias Bernet, S. Hall, T. Simon-labricAbstract:The impact of subduction processes on surface uplift and relief building in the Andes is not well understood. In northern Peru, we have access to a modern flat subduction zone (3°–15°S) where both the geometry and timing of the flattening of the slab are well constrained. Some of the highest Andean peaks, the Cordillera Blanca (6768 m) and the Cordillera Negra (5187 m), are located just above the Peruvian flat slab. This is a perfect target to explore the impact of slab flattening and associated magmatism on Andean topography and uplift. We present new apatite (U-Th)/He and fission-track data from three vertical profiles in the Cordillera Blanca and the Cordillera Negra. Time-temperature inverse modeling of the thermochronologi-cal data suggests that regional exhumation in the Cordillera Occidental started at ca. 15 Ma, synchronous with the onset of subduction of the Nazca Ridge and eastward movement of regional magmatism. We propose that ridge subduction at 15 Ma and onset of slab flattening drove regional surface uplift, with an important contribution of mag-matism to relief building in the Cordillera Occidental.
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Slab flattening, magmatism, and surface uplift in the Cordillera Occidental (northern Peru).
Geology, 2015Co-Authors: Audrey Margirier, L. Audin, C.e Gautheron, Matthias Bernet, S. Hall, X. Robert, T. Simon-labricAbstract:The impact of subduction processes on surface uplift and relief building in the Andes is not well understood. In northern Peru, we have access to a modern flat subduction zone (3 degrees-15 degrees S) where both the geometry and timing of the flattening of the slab are well constrained. Some of the highest Andean peaks, the Cordillera Blanca (6768 m) and the Cordillera Negra (5187 m), are located just above the Peruvian flat slab. This is a perfect target to explore the impact of slab flattening and associated magmatism on Andean topography and uplift. We present new apatite (U-Th)/He and fission-track data from three vertical profiles in the Cordillera Blanca and the Cordillera Negra. Time-temperature inverse modeling of the thermochronological data suggests that regional exhumation in the Cordillera Occidental started at ca. 15 Ma, synchronous with the onset of subduction of the Nazca Ridge and eastward movement of regional magmatism. We propose that ridge subduction at 15 Ma and onset of slab flattening drove regional surface uplift, with an important contribution of magmatism to relief building in the Cordillera Occidental.