| Online-Ressource |
Verfasst von: | Tazzo-Rangel, M. Daniela [VerfasserIn]  |
| Weber, Bodo [VerfasserIn]  |
| Schmitt, Axel Karl [VerfasserIn]  |
| González-Guzmán, Reneé [VerfasserIn]  |
| Cisneros de León, Alejandro [VerfasserIn]  |
| Hecht, Lutz [VerfasserIn]  |
Titel: | Permo-Triassic metamorphism in the Mérida Andes, Venezuela |
Titelzusatz: | new insights from geochronology, O-isotopes, and geothermobarometry |
Verf.angabe: | M. Daniela Tazzo-Rangel, Bodo Weber, Axel K. Schmitt, Reneé González-Guzmán, Alejandro Cisneros de León, Lutz Hecht |
E-Jahr: | 2020 |
Jahr: | 26 September 2020 |
Umfang: | 29 S. |
Illustrationen: | Diagramme, Karten |
Fussnoten: | Gesehen am 30.06.2021 |
Titel Quelle: | Enthalten in: International journal of earth sciences |
Ort Quelle: | Berlin : Springer, 1999 |
Jahr Quelle: | 2020 |
Band/Heft Quelle: | (2020) |
ISSN Quelle: | 1437-3262 |
Abstract: | Although there is a consensus about Pangea assemblage in northwestern Gondwana spanning from the Late Carboniferous to the Early Permian, the tectonics of the Permo-Triassic period, including the onset of Pangea breakup, is still controversial. In this context, three regional tectonic features need to be considered: (1) The Ouachita-Marathon-Sonora suture, (2) east-dipping subduction of the Panthalassa oceanic crust beneath Gondwana, and (3) an extensional setting documented in Colombia, Ecuador, and México suggesting Pangea breakup at ca. 240-220 Ma. A chemical, isotopic, and geochronological dataset is presented in this contribution to constrain the effects of these tectonic processes in the metamorphic basement of the Mérida Andes in western Venezuela. U-Pb Secondary Ion Mass Spectrometry analyses on unpolished surfaces of zircons from orthogneisses yielded an average age of 251 ± 4 Ma. The corresponding δ18O values suggest metamorphic recrystallization of zircon instead of high-T fluid interaction. Rb-Sr and Sm-Nd geochronology in white mica and garnet yielded ages of 234 ± 3 Ma and 249 ± 2 Ma, respectively, whereas a younger Rb-Sr date of 197 ± 1 Ma was obtained from biotite. U-Pb and Sm-Nd ages constrain the latest Permian-earliest Triassic metamorphism in the Mérida Andes at 251 ± 4 Ma. Geothermobarometry data suggest amphibolite-facies peak metamorphic conditions at ~ 685 °C and ~ 6.0 kbar. Metamorphism might be related to post-orogenic collapse, after the collision of Gondwana and Laurentia to form Pangea. Rb-Sr ages suggest retrogression and cooling, possibly caused by thermal relaxation of a tectonically overthickened crust and onset of extensional setting, followed by Pangea breakup during the Late Triassic-Early Jurassic. |
DOI: | doi:10.1007/s00531-020-01926-5 |
URL: | Bitte beachten Sie: Dies ist ein Bibliographieeintrag. Ein Volltextzugriff für Mitglieder der Universität besteht hier nur, falls für die entsprechende Zeitschrift/den entsprechenden Sammelband ein Abonnement besteht oder es sich um einen OpenAccess-Titel handelt.
Volltext: https://doi.org/10.1007/s00531-020-01926-5 |
| DOI: https://doi.org/10.1007/s00531-020-01926-5 |
Datenträger: | Online-Ressource |
Sprache: | eng |
K10plus-PPN: | 1761638947 |
Verknüpfungen: | → Zeitschrift |
Permo-Triassic metamorphism in the Mérida Andes, Venezuela / Tazzo-Rangel, M. Daniela [VerfasserIn]; 26 September 2020 (Online-Ressource)