Palaeomagnetism and 40Ar/ 39Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: Further data to explore tectonomagmatic events associated with the break-up of Gondwana

New 40Ar/ 39Ar data indicate ages of c. 185 Ma for the Lonco Trapial volcanic field in Gastre, north-central Patagonia, implying that this andesitic unit is roughly coeval with the Marifil silicic province that crops out in the eastern part of northern Patagonia. These volcanic fields are therefore...

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Autores principales: Zaffarana, C.B., Somoza, R.
Formato: JOUR
Materias:
Central Patagonia
Clockwise rotation
Crustal block
Early Jurassic
Fault system
Finite rotations
Jurassic
Large igneous provinces
Palaeomagnetism
Patagonia
South America
Tectonic activity
Volcanic field
Strike-slip faults
Volcanoes
Geomagnetism
age determination
argon-argon dating
continental breakup
crustal structure
deformation
displacement
Gondwana
large igneous province
outcrop
paleomagnetism
strike-slip fault
tectonic rotation
Falkland Islands (Malvinas)
Karoo
South Africa
Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00167649_v169_n4_p371_Zaffarana
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
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spelling todo:paper_00167649_v169_n4_p371_Zaffarana2023-10-03T14:14:47Z Palaeomagnetism and 40Ar/ 39Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: Further data to explore tectonomagmatic events associated with the break-up of Gondwana Zaffarana, C.B. Somoza, R. Central Patagonia Clockwise rotation Crustal block Early Jurassic Fault system Finite rotations Jurassic Large igneous provinces Palaeomagnetism Patagonia South America Tectonic activity Volcanic field Strike-slip faults Volcanoes Geomagnetism age determination argon-argon dating continental breakup crustal structure deformation displacement Gondwana Jurassic large igneous province outcrop paleomagnetism strike-slip fault tectonic rotation Falkland Islands (Malvinas) Karoo Patagonia South Africa New 40Ar/ 39Ar data indicate ages of c. 185 Ma for the Lonco Trapial volcanic field in Gastre, north-central Patagonia, implying that this andesitic unit is roughly coeval with the Marifil silicic province that crops out in the eastern part of northern Patagonia. These volcanic fields are therefore roughly coeval with the Karoo-Ferrar large igneous province, further contributing to the huge, 185-180 Ma magmatic outpouring in southern Gondwana. The comparison of palaeomagnetic results from the unit with Early Jurassic reference palaeopoles suggests that Gastre records a small, anticlockwise finite rotation with respect to stable South America. This contrasts sharply with the large clockwise rotation recorded by roughly coeval dolerites from the Falkland/Malvinas Islands, and argues against a direct relationship between the rotation of the islands and the tectonic activity in Gastre. The results support previous suggestions that the Gastre Fault System is not the locus of major strike-slip displacement activity in the Jurassic as some workers have suggested. Taken as a whole, palaeomagnetic data from Patagonia suggest a more complex than previously thought pattern of distributed and variable deformation during the early stages of Gondwana breakup. The crustal block boundaries in the region remain cryptic. Fil:Zaffarana, C.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Somoza, R. 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_00167649_v169_n4_p371_Zaffarana
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Central Patagonia
Clockwise rotation
Crustal block
Early Jurassic
Fault system
Finite rotations
Jurassic
Large igneous provinces
Palaeomagnetism
Patagonia
South America
Tectonic activity
Volcanic field
Strike-slip faults
Volcanoes
Geomagnetism
age determination
argon-argon dating
continental breakup
crustal structure
deformation
displacement
Gondwana
Jurassic
large igneous province
outcrop
paleomagnetism
strike-slip fault
tectonic rotation
Falkland Islands (Malvinas)
Karoo
Patagonia
South Africa
spellingShingle Central Patagonia
Clockwise rotation
Crustal block
Early Jurassic
Fault system
Finite rotations
Jurassic
Large igneous provinces
Palaeomagnetism
Patagonia
South America
Tectonic activity
Volcanic field
Strike-slip faults
Volcanoes
Geomagnetism
age determination
argon-argon dating
continental breakup
crustal structure
deformation
displacement
Gondwana
Jurassic
large igneous province
outcrop
paleomagnetism
strike-slip fault
tectonic rotation
Falkland Islands (Malvinas)
Karoo
Patagonia
South Africa
Zaffarana, C.B.
Somoza, R.
Palaeomagnetism and 40Ar/ 39Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: Further data to explore tectonomagmatic events associated with the break-up of Gondwana
topic_facet Central Patagonia
Clockwise rotation
Crustal block
Early Jurassic
Fault system
Finite rotations
Jurassic
Large igneous provinces
Palaeomagnetism
Patagonia
South America
Tectonic activity
Volcanic field
Strike-slip faults
Volcanoes
Geomagnetism
age determination
argon-argon dating
continental breakup
crustal structure
deformation
displacement
Gondwana
Jurassic
large igneous province
outcrop
paleomagnetism
strike-slip fault
tectonic rotation
Falkland Islands (Malvinas)
Karoo
Patagonia
South Africa
description New 40Ar/ 39Ar data indicate ages of c. 185 Ma for the Lonco Trapial volcanic field in Gastre, north-central Patagonia, implying that this andesitic unit is roughly coeval with the Marifil silicic province that crops out in the eastern part of northern Patagonia. These volcanic fields are therefore roughly coeval with the Karoo-Ferrar large igneous province, further contributing to the huge, 185-180 Ma magmatic outpouring in southern Gondwana. The comparison of palaeomagnetic results from the unit with Early Jurassic reference palaeopoles suggests that Gastre records a small, anticlockwise finite rotation with respect to stable South America. This contrasts sharply with the large clockwise rotation recorded by roughly coeval dolerites from the Falkland/Malvinas Islands, and argues against a direct relationship between the rotation of the islands and the tectonic activity in Gastre. The results support previous suggestions that the Gastre Fault System is not the locus of major strike-slip displacement activity in the Jurassic as some workers have suggested. Taken as a whole, palaeomagnetic data from Patagonia suggest a more complex than previously thought pattern of distributed and variable deformation during the early stages of Gondwana breakup. The crustal block boundaries in the region remain cryptic.
format JOUR
author Zaffarana, C.B.
Somoza, R.
author_facet Zaffarana, C.B.
Somoza, R.
author_sort Zaffarana, C.B.
title Palaeomagnetism and 40Ar/ 39Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: Further data to explore tectonomagmatic events associated with the break-up of Gondwana
title_short Palaeomagnetism and 40Ar/ 39Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: Further data to explore tectonomagmatic events associated with the break-up of Gondwana
title_full Palaeomagnetism and 40Ar/ 39Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: Further data to explore tectonomagmatic events associated with the break-up of Gondwana
title_fullStr Palaeomagnetism and 40Ar/ 39Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: Further data to explore tectonomagmatic events associated with the break-up of Gondwana
title_full_unstemmed Palaeomagnetism and 40Ar/ 39Ar dating from Lower Jurassic rocks in Gastre, central Patagonia: Further data to explore tectonomagmatic events associated with the break-up of Gondwana
title_sort palaeomagnetism and 40ar/ 39ar dating from lower jurassic rocks in gastre, central patagonia: further data to explore tectonomagmatic events associated with the break-up of gondwana
url http://hdl.handle.net/20.500.12110/paper_00167649_v169_n4_p371_Zaffarana
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AT somozar palaeomagnetismand40ar39ardatingfromlowerjurassicrocksingastrecentralpatagoniafurtherdatatoexploretectonomagmaticeventsassociatedwiththebreakupofgondwana
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