Magnetic fabric and microstructures of Late Paleozoic granitoids from the North Patagonian Massif: Evidence of a collision between Patagonia and Gondwana?
Widespread Late Paleozoic magmatism in northern Patagonia is a target to test hypotheses on the long standing question over the origin of Patagonia. In recent years, a dispute over whether it is an accreted crustal block that collided with Gondwana in Paleozoic times or an autochthonous part of Sout...
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todo:paper_00401951_v494_n1-2_p118_LopezdeLuchi |
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Universidad de Buenos Aires |
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I-28 |
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R-134 |
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Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Collision Patagonia and Gondwana Late Paleozoic granitoids Magnetic fabric Microstructures North Patagonian Massif Anisotropy of magnetic susceptibility Combined analysis Compressional Crustal block Frontal collision Granodiorite High temperature Late Paleozoic Late Permian Magmatisms Magnetic fabrics Micro-structural North Patagonian Massif Ordovician Paleomagnetic data Paleozoic Patagonia Permian Solid state deformation South America Stress field Systematic analysis Tectonic events Thin section Deformation Geochronology Granite Magnetic anisotropy Magnetic susceptibility Magnetism Microstructure Tungsten compounds Carboniferous collision zone deformation mechanism emplacement Gondwana granitoid integrated approach magmatism magnetic anisotropy magnetic fabric microstructure paleomagnetism Paleozoic Permian petrography Patagonia |
| spellingShingle |
Collision Patagonia and Gondwana Late Paleozoic granitoids Magnetic fabric Microstructures North Patagonian Massif Anisotropy of magnetic susceptibility Combined analysis Compressional Crustal block Frontal collision Granodiorite High temperature Late Paleozoic Late Permian Magmatisms Magnetic fabrics Micro-structural North Patagonian Massif Ordovician Paleomagnetic data Paleozoic Patagonia Permian Solid state deformation South America Stress field Systematic analysis Tectonic events Thin section Deformation Geochronology Granite Magnetic anisotropy Magnetic susceptibility Magnetism Microstructure Tungsten compounds Carboniferous collision zone deformation mechanism emplacement Gondwana granitoid integrated approach magmatism magnetic anisotropy magnetic fabric microstructure paleomagnetism Paleozoic Permian petrography Patagonia López de Luchi, M.G. Rapalini, A.E. Tomezzoli, R.N. Magnetic fabric and microstructures of Late Paleozoic granitoids from the North Patagonian Massif: Evidence of a collision between Patagonia and Gondwana? |
| topic_facet |
Collision Patagonia and Gondwana Late Paleozoic granitoids Magnetic fabric Microstructures North Patagonian Massif Anisotropy of magnetic susceptibility Combined analysis Compressional Crustal block Frontal collision Granodiorite High temperature Late Paleozoic Late Permian Magmatisms Magnetic fabrics Micro-structural North Patagonian Massif Ordovician Paleomagnetic data Paleozoic Patagonia Permian Solid state deformation South America Stress field Systematic analysis Tectonic events Thin section Deformation Geochronology Granite Magnetic anisotropy Magnetic susceptibility Magnetism Microstructure Tungsten compounds Carboniferous collision zone deformation mechanism emplacement Gondwana granitoid integrated approach magmatism magnetic anisotropy magnetic fabric microstructure paleomagnetism Paleozoic Permian petrography Patagonia |
| description |
Widespread Late Paleozoic magmatism in northern Patagonia is a target to test hypotheses on the long standing question over the origin of Patagonia. In recent years, a dispute over whether it is an accreted crustal block that collided with Gondwana in Paleozoic times or an autochthonous part of South America has taken place. As part of a multidisciplinary study, an integrated microstructural and magnetic fabric study was carried out on the Late Carboniferous Yaminué Complex and the Early Permian Navarrete Plutonic Complex, both exposed in the northeastern corner of the North Patagonian Massif (40.5°S, 67.0°W). Other investigated units are the Late Carboniferous Tardugno Granodiorite, the newly defined Cabeza de Vaca Granite and the Late Permian San Martin pluton. Over 300 oriented cores from 60 sites were collected for anisotropy of magnetic susceptibility (AMS) measurements. A systematic analysis of around 100 petrographic thin sections was performed to characterize the microstructures of the different magmatic units. Microstructures in the Yaminué Complex are indicative of a transition from magmatic to solid-state deformation. Microstructures of the orthogneiss of tonalitic composition suggest an early stage in the emplacement history of this complex. The Cabeza de Vaca Granite, intrusive in Yaminué Complex, is the most evolved unit and records less intense high-temperature solid-state deformation which suggests that the stress field that controlled the emplacement of the Yaminué Complex outlasted it. According to petrologic and structural considerations, the Navarrete Plutonic Complex has been subdivided into three facies, i.e. Robaina, Guanacos and Aranda, respectively. Microstructures of the Navarrete Plutonic Complex are mostly magmatic to submagmatic, versus the solid-state fabric that characterizes the Robaina facies at the contact with the Yaminué Complex. Combined analyses of AMS and microstructural data lead us to suggest that the Yaminué Complex, Cabeza de Vaca Granite and possibly Tardugno Granodiorite were intruded during a major compressional event associated with top-to-the-SSW thrusting. This event is most likely related to a frontal collision of the North Patagonian Massif and the southwestern Gondwana margin at around 300. Ma. The Navarrete Plutonic Complex and San Martin pluton were emplaced after that tectonic event, which must have ended by 281. Ma. Previous magmatic, geochronological and paleomagnetic data that suggest close connection of the North Patagonian Massif with the South American Gondwana blocks during the Paleozoic, can be reconciled with a Late Paleozoic collision by a model of a para-autochthonous North Patagonian Massif that rifted away from Gondwana after the Ordovician and collided again in the Late Carboniferous-Early Permian. © 2010 Elsevier B.V. |
| format |
JOUR |
| author |
López de Luchi, M.G. Rapalini, A.E. Tomezzoli, R.N. |
| author_facet |
López de Luchi, M.G. Rapalini, A.E. Tomezzoli, R.N. |
| author_sort |
López de Luchi, M.G. |
| title |
Magnetic fabric and microstructures of Late Paleozoic granitoids from the North Patagonian Massif: Evidence of a collision between Patagonia and Gondwana? |
| title_short |
Magnetic fabric and microstructures of Late Paleozoic granitoids from the North Patagonian Massif: Evidence of a collision between Patagonia and Gondwana? |
| title_full |
Magnetic fabric and microstructures of Late Paleozoic granitoids from the North Patagonian Massif: Evidence of a collision between Patagonia and Gondwana? |
| title_fullStr |
Magnetic fabric and microstructures of Late Paleozoic granitoids from the North Patagonian Massif: Evidence of a collision between Patagonia and Gondwana? |
| title_full_unstemmed |
Magnetic fabric and microstructures of Late Paleozoic granitoids from the North Patagonian Massif: Evidence of a collision between Patagonia and Gondwana? |
| title_sort |
magnetic fabric and microstructures of late paleozoic granitoids from the north patagonian massif: evidence of a collision between patagonia and gondwana? |
| url |
http://hdl.handle.net/20.500.12110/paper_00401951_v494_n1-2_p118_LopezdeLuchi |
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AT lopezdeluchimg magneticfabricandmicrostructuresoflatepaleozoicgranitoidsfromthenorthpatagonianmassifevidenceofacollisionbetweenpatagoniaandgondwana AT rapaliniae magneticfabricandmicrostructuresoflatepaleozoicgranitoidsfromthenorthpatagonianmassifevidenceofacollisionbetweenpatagoniaandgondwana AT tomezzolirn magneticfabricandmicrostructuresoflatepaleozoicgranitoidsfromthenorthpatagonianmassifevidenceofacollisionbetweenpatagoniaandgondwana |
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1782026787931291648 |
| spelling |
todo:paper_00401951_v494_n1-2_p118_LopezdeLuchi2023-10-03T14:50:15Z Magnetic fabric and microstructures of Late Paleozoic granitoids from the North Patagonian Massif: Evidence of a collision between Patagonia and Gondwana? López de Luchi, M.G. Rapalini, A.E. Tomezzoli, R.N. Collision Patagonia and Gondwana Late Paleozoic granitoids Magnetic fabric Microstructures North Patagonian Massif Anisotropy of magnetic susceptibility Combined analysis Compressional Crustal block Frontal collision Granodiorite High temperature Late Paleozoic Late Permian Magmatisms Magnetic fabrics Micro-structural North Patagonian Massif Ordovician Paleomagnetic data Paleozoic Patagonia Permian Solid state deformation South America Stress field Systematic analysis Tectonic events Thin section Deformation Geochronology Granite Magnetic anisotropy Magnetic susceptibility Magnetism Microstructure Tungsten compounds Carboniferous collision zone deformation mechanism emplacement Gondwana granitoid integrated approach magmatism magnetic anisotropy magnetic fabric microstructure paleomagnetism Paleozoic Permian petrography Patagonia Widespread Late Paleozoic magmatism in northern Patagonia is a target to test hypotheses on the long standing question over the origin of Patagonia. In recent years, a dispute over whether it is an accreted crustal block that collided with Gondwana in Paleozoic times or an autochthonous part of South America has taken place. As part of a multidisciplinary study, an integrated microstructural and magnetic fabric study was carried out on the Late Carboniferous Yaminué Complex and the Early Permian Navarrete Plutonic Complex, both exposed in the northeastern corner of the North Patagonian Massif (40.5°S, 67.0°W). Other investigated units are the Late Carboniferous Tardugno Granodiorite, the newly defined Cabeza de Vaca Granite and the Late Permian San Martin pluton. Over 300 oriented cores from 60 sites were collected for anisotropy of magnetic susceptibility (AMS) measurements. A systematic analysis of around 100 petrographic thin sections was performed to characterize the microstructures of the different magmatic units. Microstructures in the Yaminué Complex are indicative of a transition from magmatic to solid-state deformation. Microstructures of the orthogneiss of tonalitic composition suggest an early stage in the emplacement history of this complex. The Cabeza de Vaca Granite, intrusive in Yaminué Complex, is the most evolved unit and records less intense high-temperature solid-state deformation which suggests that the stress field that controlled the emplacement of the Yaminué Complex outlasted it. According to petrologic and structural considerations, the Navarrete Plutonic Complex has been subdivided into three facies, i.e. Robaina, Guanacos and Aranda, respectively. Microstructures of the Navarrete Plutonic Complex are mostly magmatic to submagmatic, versus the solid-state fabric that characterizes the Robaina facies at the contact with the Yaminué Complex. Combined analyses of AMS and microstructural data lead us to suggest that the Yaminué Complex, Cabeza de Vaca Granite and possibly Tardugno Granodiorite were intruded during a major compressional event associated with top-to-the-SSW thrusting. This event is most likely related to a frontal collision of the North Patagonian Massif and the southwestern Gondwana margin at around 300. Ma. The Navarrete Plutonic Complex and San Martin pluton were emplaced after that tectonic event, which must have ended by 281. Ma. Previous magmatic, geochronological and paleomagnetic data that suggest close connection of the North Patagonian Massif with the South American Gondwana blocks during the Paleozoic, can be reconciled with a Late Paleozoic collision by a model of a para-autochthonous North Patagonian Massif that rifted away from Gondwana after the Ordovician and collided again in the Late Carboniferous-Early Permian. © 2010 Elsevier B.V. Fil:Rapalini, A.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Tomezzoli, R.N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00401951_v494_n1-2_p118_LopezdeLuchi |