The mid-Variscan suture in the Morais complex of Trás-os-Montes (Portugal): insights from geochemistry and geochronology of oceanic rocks
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F24%3A10169287" target="_blank" >RIV/00025798:_____/24:10169287 - isvavai.cz</a>
Result on the web
<a href="https://doi.org/10.1080/00206814.2024.2411534" target="_blank" >https://doi.org/10.1080/00206814.2024.2411534</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1080/00206814.2024.2411534" target="_blank" >10.1080/00206814.2024.2411534</a>
Alternative languages
Result language
angličtina
Original language name
The mid-Variscan suture in the Morais complex of Trás-os-Montes (Portugal): insights from geochemistry and geochronology of oceanic rocks
Original language description
The Middle Allochthon of the Galicia-Tr & aacute;s-os-Montes Zone (GTMZ) in NW Iberia is an assemblage of oceanic units representing the Variscan suture of one or more peri-Gondwanan oceans. This contribution brings new geochronological and geochemical data from the Middle Allochthon of the Morais Complex, in northern Portugal. There, the oceanic ensemble consists of a stack of five tectonic units which from bottom to top are the Junqueira, Pombais and Izeda oceanic supracrustals and the Remondes and Morais-Talhinhas ophiolitic units. The Junqueira and Pombais units consist of greenschists and metapelites. No age data are available for these two units, but a correlation is established with a Cambro-Ordovician unit in the & Oacute;rdenes Complex of Galicia (NW Spain) dated at 500 Ma. The Izeda Unit consists of fine-grained, low-grade amphibolites transitional to epidote-amphibolites and greenschists, for which an age of 484 +/- 3 Ma has been obtained for a metabasic tuff. In the ophiolitic ensemble, the Remondes and Morais-Talhinhas units consist of fine-grained amphibolites associated with deformed metagabbros, mafic cumulates and serpentinized ultramafics. In this study, two plagiogranite samples from the Remondes Unit yielded a complex spread of age data with Silurian ages representing the dominant population. This suggests that the newly defined Remondes Unit is younger than the Izeda Unit but older than the previously published age for these rocks, which are considered part of the overlying Morais-Talhinhas Unit, dated as Devonian (406-395 Ma) in a previous study. The geochemistry of the basic rocks in the five units is that of NMORB with a subduction-derived component that varies from weak to null. The ages, together with new and previously published whole rock geochemical data obtained from basic igneous samples, are interpreted to date and reflect the formation of igneous protoliths in oceanic ridge settings associated with the Mid-Variscan Ocean, a part of the Rheic oceanic realm that registered magmatic activity between the late Cambrian and the Lower Devonian.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10505 - Geology
Result continuities
Project
—
Continuities
V - Vyzkumna aktivita podporovana z jinych verejnych zdroju
Others
Publication year
2024
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
International Geology Review
ISSN
0020-6814
e-ISSN
1938-2839
Volume of the periodical
66
Issue of the periodical within the volume
22
Country of publishing house
US - UNITED STATES
Number of pages
33
Pages from-to
3882-3914
UT code for WoS article
001327545600001
EID of the result in the Scopus database
2-s2.0-85205731441