The intermediate to acid Choiyoi Magmatic Province is the most conspicuous feature along the Late... more The intermediate to acid Choiyoi Magmatic Province is the most conspicuous feature along the Late Paleozic continental margin of southwestern Gondwana, and is generally regarded as the possible source for the widespread ash fall deposits interlayered with sedimentary sequences in the adjacent Gondwana basins. The Choiyoi magmatism is geologically constrained between the early Permian San Rafael orogenic phase and the Triassic extensional Huarpica phase in the region of Argentine Frontal Cordillera, Precordillera and San Rafael Block. In order to better assess the Choiyoi magmatism in Argentine Frontal Cordillera, we obtained 6 new LA-ICPMS UePb ages between 278.8 ± 3.4 Ma and 252.5 ± 1.9 Ma from plutonic rocks of the Colangüil Batholith and an associated volcanic rock. The global analysis of age data compiled from Chilean and Argentine Late Paleozoic to Triassic outcrops allows us to identify three stages of magmatism: (1) pre-Choiyoi orogenic magmatism, (2) Choiyoi magmatism (286e247 Ma), and (3) post-Choiyoi magmatism related to extensional tectonics. In the Choiyoi stage is there an eastward shift and expansion of the magmatism to the southeast, covering an extensive region that defines the Choiyoi magmatic province. On the basis of comparison with the ages from volcanogenic levels identified in the coeval Gondwana basins, we propose: (a) The pre-Choiyoi volcanism from the Paganzo basin (320 e296 Ma) probably has a local source in addition to the Frontal Cordillera region. (b) The pre-Choiyoi and Choiyoi events identified in the Parana basin (304e275 Ma) are likely to have their source in the Chilean Precordillera. (c) The early stage of the Choiyoi magmatism found in the Sauce Grande basin (284 e281 Ma) may have come from the adjacent Las Matras to Chadileuvú blocks. (d) The pre-Choiyoi and Choiyoi events in the Karoo basins (302e253 Ma) include the longest Choiyoi interval, and as a whole bear the best resemblance to the age records along the Chilean and Argentine Frontal Cordillera.
Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural mod... more Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural modifications as a result of the coalescence of two plutons, Alpa Corral and Talita, during the construction of a large granitic batholith, Cerro Aspero, in the Sierras Pampeanas of Córdoba (Argentina). The Alpa Corral granite is a small and nearly circular pluton, while the larger Talita pluton displays a marked N–S elongation. The NW quadrangle of the Alpa Corral pluton underwent a deformation resulting in foliation trajectories that outline a crescent moon pattern whose inner arc is concordant with the Alpa Corral/Talita contact. The highest values for the magnetic susceptibility and its anisotropy are concentrated in the coalescence zone between both plutons. The magmatic and sub-magmatic nature of the microstructures demonstrates that such a deformation was caused by the southward overriding of the largest Talita pluton while the Alpa Corral pluton was not yet fully crystallized. Rb–Sr geochronology indicates that this process took place 369±9Ma ago, long after the Famatinian (Ordovician to Early Devonian) deformation of the country rocks, which confirms a synmagmatic, rather than a regional, deformational event.
... Precordillera) y mesozoico-cenozoicos (Cuenca Cuyana); en otras constituyen pequeños aflorami... more ... Precordillera) y mesozoico-cenozoicos (Cuenca Cuyana); en otras constituyen pequeños afloramientos emergentes en frentes de cabalgamientos (Bloque de San Rafael; Bloque de ... Las rocas del basamento fueron ubicadas tentativamente en el Precámbrico por Furque (1972 ...
El Sótano Granodiorite: a deformed Jurassic pluton in the basement of Las Grutas, Atlantic Northp... more El Sótano Granodiorite: a deformed Jurassic pluton in the basement of Las Grutas, Atlantic Northpatagonian Massif. Igneous and metamorphic rocks belonging to a crystalline basement crop out to the south of Las Grutas beach, Río Negro Province. Within these rocks, a small granodioritic exposure was identified and named El Sótano Granodiorite. The granodiorite shows a magmatic foliation developed by NW-trending
... Pre-Batholith Structures and the San Rafael Orogenic Phase ... In the northern edge of CB, in... more ... Pre-Batholith Structures and the San Rafael Orogenic Phase ... In the northern edge of CB, in the region of San Guillermo, the country rock is sedimentary, affected by a weak regional metamorphism, probably lower Paleozoic in age (Furque, 1972). ...
Journal of Structural Geology - J STRUCT GEOL, 2006
Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural mod... more Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural modifications as a result of the coalescence of two plutons, Alpa Corral and Talita, during the construction of a large granitic batholith, Cerro Aspero, in the Sierras Pampeanas of Córdoba (Argentina). The Alpa Corral granite is a small and nearly circular pluton, while the larger Talita pluton displays a marked N–S elongation. The NW quadrangle of the Alpa Corral pluton underwent a deformation resulting in foliation trajectories that outline a crescent moon pattern whose inner arc is concordant with the Alpa Corral/Talita contact. The highest values for the magnetic susceptibility and its anisotropy are concentrated in the coalescence zone between both plutons. The magmatic and sub-magmatic nature of the microstructures demonstrates that such a deformation was caused by the southward overriding of the largest Talita pluton while the Alpa Corral pluton was not yet fully crystallized. Rb–Sr...
The intermediate to acid Choiyoi Magmatic Province is the most conspicuous feature along the Late... more The intermediate to acid Choiyoi Magmatic Province is the most conspicuous feature along the Late Paleozic continental margin of southwestern Gondwana, and is generally regarded as the possible source for the widespread ash fall deposits interlayered with sedimentary sequences in the adjacent Gondwana basins. The Choiyoi magmatism is geologically constrained between the early Permian San Rafael orogenic phase and the Triassic extensional Huarpica phase in the region of Argentine Frontal Cordillera, Precordillera and San Rafael Block. In order to better assess the Choiyoi magmatism in Argentine Frontal Cordillera, we obtained 6 new LA-ICPMS UePb ages between 278.8 ± 3.4 Ma and 252.5 ± 1.9 Ma from plutonic rocks of the Colangüil Batholith and an associated volcanic rock. The global analysis of age data compiled from Chilean and Argentine Late Paleozoic to Triassic outcrops allows us to identify three stages of magmatism: (1) pre-Choiyoi orogenic magmatism, (2) Choiyoi magmatism (286e247 Ma), and (3) post-Choiyoi magmatism related to extensional tectonics. In the Choiyoi stage is there an eastward shift and expansion of the magmatism to the southeast, covering an extensive region that defines the Choiyoi magmatic province. On the basis of comparison with the ages from volcanogenic levels identified in the coeval Gondwana basins, we propose: (a) The pre-Choiyoi volcanism from the Paganzo basin (320 e296 Ma) probably has a local source in addition to the Frontal Cordillera region. (b) The pre-Choiyoi and Choiyoi events identified in the Parana basin (304e275 Ma) are likely to have their source in the Chilean Precordillera. (c) The early stage of the Choiyoi magmatism found in the Sauce Grande basin (284 e281 Ma) may have come from the adjacent Las Matras to Chadileuvú blocks. (d) The pre-Choiyoi and Choiyoi events in the Karoo basins (302e253 Ma) include the longest Choiyoi interval, and as a whole bear the best resemblance to the age records along the Chilean and Argentine Frontal Cordillera.
Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural mod... more Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural modifications as a result of the coalescence of two plutons, Alpa Corral and Talita, during the construction of a large granitic batholith, Cerro Aspero, in the Sierras Pampeanas of Córdoba (Argentina). The Alpa Corral granite is a small and nearly circular pluton, while the larger Talita pluton displays a marked N–S elongation. The NW quadrangle of the Alpa Corral pluton underwent a deformation resulting in foliation trajectories that outline a crescent moon pattern whose inner arc is concordant with the Alpa Corral/Talita contact. The highest values for the magnetic susceptibility and its anisotropy are concentrated in the coalescence zone between both plutons. The magmatic and sub-magmatic nature of the microstructures demonstrates that such a deformation was caused by the southward overriding of the largest Talita pluton while the Alpa Corral pluton was not yet fully crystallized. Rb–Sr geochronology indicates that this process took place 369±9Ma ago, long after the Famatinian (Ordovician to Early Devonian) deformation of the country rocks, which confirms a synmagmatic, rather than a regional, deformational event.
... Precordillera) y mesozoico-cenozoicos (Cuenca Cuyana); en otras constituyen pequeños aflorami... more ... Precordillera) y mesozoico-cenozoicos (Cuenca Cuyana); en otras constituyen pequeños afloramientos emergentes en frentes de cabalgamientos (Bloque de San Rafael; Bloque de ... Las rocas del basamento fueron ubicadas tentativamente en el Precámbrico por Furque (1972 ...
El Sótano Granodiorite: a deformed Jurassic pluton in the basement of Las Grutas, Atlantic Northp... more El Sótano Granodiorite: a deformed Jurassic pluton in the basement of Las Grutas, Atlantic Northpatagonian Massif. Igneous and metamorphic rocks belonging to a crystalline basement crop out to the south of Las Grutas beach, Río Negro Province. Within these rocks, a small granodioritic exposure was identified and named El Sótano Granodiorite. The granodiorite shows a magmatic foliation developed by NW-trending
... Pre-Batholith Structures and the San Rafael Orogenic Phase ... In the northern edge of CB, in... more ... Pre-Batholith Structures and the San Rafael Orogenic Phase ... In the northern edge of CB, in the region of San Guillermo, the country rock is sedimentary, affected by a weak regional metamorphism, probably lower Paleozoic in age (Furque, 1972). ...
Journal of Structural Geology - J STRUCT GEOL, 2006
Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural mod... more Magnetic fabric patterns and microstructures of granitic rocks provide evidence of structural modifications as a result of the coalescence of two plutons, Alpa Corral and Talita, during the construction of a large granitic batholith, Cerro Aspero, in the Sierras Pampeanas of Córdoba (Argentina). The Alpa Corral granite is a small and nearly circular pluton, while the larger Talita pluton displays a marked N–S elongation. The NW quadrangle of the Alpa Corral pluton underwent a deformation resulting in foliation trajectories that outline a crescent moon pattern whose inner arc is concordant with the Alpa Corral/Talita contact. The highest values for the magnetic susceptibility and its anisotropy are concentrated in the coalescence zone between both plutons. The magmatic and sub-magmatic nature of the microstructures demonstrates that such a deformation was caused by the southward overriding of the largest Talita pluton while the Alpa Corral pluton was not yet fully crystallized. Rb–Sr...
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Paleozic continental margin of southwestern Gondwana, and is generally regarded as the possible source
for the widespread ash fall deposits interlayered with sedimentary sequences in the adjacent Gondwana
basins. The Choiyoi magmatism is geologically constrained between the early Permian San Rafael
orogenic phase and the Triassic extensional Huarpica phase in the region of Argentine Frontal Cordillera,
Precordillera and San Rafael Block. In order to better assess the Choiyoi magmatism in Argentine Frontal
Cordillera, we obtained 6 new LA-ICPMS UePb ages between 278.8 ± 3.4 Ma and 252.5 ± 1.9 Ma from
plutonic rocks of the Colangüil Batholith and an associated volcanic rock. The global analysis of age data
compiled from Chilean and Argentine Late Paleozoic to Triassic outcrops allows us to identify three stages
of magmatism: (1) pre-Choiyoi orogenic magmatism, (2) Choiyoi magmatism (286e247 Ma), and (3)
post-Choiyoi magmatism related to extensional tectonics. In the Choiyoi stage is there an eastward shift
and expansion of the magmatism to the southeast, covering an extensive region that defines the Choiyoi
magmatic province. On the basis of comparison with the ages from volcanogenic levels identified in the
coeval Gondwana basins, we propose: (a) The pre-Choiyoi volcanism from the Paganzo basin (320
e296 Ma) probably has a local source in addition to the Frontal Cordillera region. (b) The pre-Choiyoi and
Choiyoi events identified in the Parana basin (304e275 Ma) are likely to have their source in the Chilean
Precordillera. (c) The early stage of the Choiyoi magmatism found in the Sauce Grande basin (284
e281 Ma) may have come from the adjacent Las Matras to Chadileuvú blocks. (d) The pre-Choiyoi and
Choiyoi events in the Karoo basins (302e253 Ma) include the longest Choiyoi interval, and as a whole
bear the best resemblance to the age records along the Chilean and Argentine Frontal Cordillera.
Paleozic continental margin of southwestern Gondwana, and is generally regarded as the possible source
for the widespread ash fall deposits interlayered with sedimentary sequences in the adjacent Gondwana
basins. The Choiyoi magmatism is geologically constrained between the early Permian San Rafael
orogenic phase and the Triassic extensional Huarpica phase in the region of Argentine Frontal Cordillera,
Precordillera and San Rafael Block. In order to better assess the Choiyoi magmatism in Argentine Frontal
Cordillera, we obtained 6 new LA-ICPMS UePb ages between 278.8 ± 3.4 Ma and 252.5 ± 1.9 Ma from
plutonic rocks of the Colangüil Batholith and an associated volcanic rock. The global analysis of age data
compiled from Chilean and Argentine Late Paleozoic to Triassic outcrops allows us to identify three stages
of magmatism: (1) pre-Choiyoi orogenic magmatism, (2) Choiyoi magmatism (286e247 Ma), and (3)
post-Choiyoi magmatism related to extensional tectonics. In the Choiyoi stage is there an eastward shift
and expansion of the magmatism to the southeast, covering an extensive region that defines the Choiyoi
magmatic province. On the basis of comparison with the ages from volcanogenic levels identified in the
coeval Gondwana basins, we propose: (a) The pre-Choiyoi volcanism from the Paganzo basin (320
e296 Ma) probably has a local source in addition to the Frontal Cordillera region. (b) The pre-Choiyoi and
Choiyoi events identified in the Parana basin (304e275 Ma) are likely to have their source in the Chilean
Precordillera. (c) The early stage of the Choiyoi magmatism found in the Sauce Grande basin (284
e281 Ma) may have come from the adjacent Las Matras to Chadileuvú blocks. (d) The pre-Choiyoi and
Choiyoi events in the Karoo basins (302e253 Ma) include the longest Choiyoi interval, and as a whole
bear the best resemblance to the age records along the Chilean and Argentine Frontal Cordillera.