A vestige of an Ediacaran magmatic arc in southeast France and its significance for the northern Gondwana margin

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F23%3A10168719" target="_blank" >RIV/00025798:_____/23:10168719 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1007/s00531-022-02277-z" target="_blank" >https://doi.org/10.1007/s00531-022-02277-z</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s00531-022-02277-z" target="_blank" >10.1007/s00531-022-02277-z</a>

Jazyk výsledku

angličtina

Název v původním jazyce

A vestige of an Ediacaran magmatic arc in southeast France and its significance for the northern Gondwana margin

Popis výsledku v původním jazyce

The Maures-Tanneron Massif is a key to putting new constraints on the age, nature, and tectonic setting of pre-Variscan metaigneous rocks in the southern Variscan Belt. Whole-rock geochemistry was combined with U-Pb isotopic data on zircon to gain insight into the pre-Variscan evolution and improve the knowledge of the southern Variscan domain. The geochemical study shows that the protolith of the studied samples is a high-K calc-alkaline granodiorite emplaced in the upper plate of a subduction zone, most probably in a continental arc setting, as suggested by numerous microdioritic enclaves. Zircon cores record a spread of ages between 609 and 548 Ma and define an age peak at c. 590 Ma, interpreted as the most likely emplacement age of the granodioritic protolith. This Ediacaran population shows a consistent zircon Th/U ratio (similar to 0.5) which likely indicates long-lived magmatic activity in a continental arc setting and corroborates our geochemical interpretations. The zircon overgrowth rims give ages from 505 to 460 Ma and might be of metamorphic origin (lower Th/U ratios), related to an important tectonothermal event that developed during Lower to Middle Ordovician times. The occurrence of older zircon grains (c. 1000 Ma and c. 1800-2500 Ma), either inherited from a crustal source or incorporated from country rocks during magma ascent, provides some constraints on the paleoposition of the magmatic arc, likely situated on the eastern shelf of the northern Gondwana margin.

Název v anglickém jazyce

A vestige of an Ediacaran magmatic arc in southeast France and its significance for the northern Gondwana margin

Popis výsledku anglicky

The Maures-Tanneron Massif is a key to putting new constraints on the age, nature, and tectonic setting of pre-Variscan metaigneous rocks in the southern Variscan Belt. Whole-rock geochemistry was combined with U-Pb isotopic data on zircon to gain insight into the pre-Variscan evolution and improve the knowledge of the southern Variscan domain. The geochemical study shows that the protolith of the studied samples is a high-K calc-alkaline granodiorite emplaced in the upper plate of a subduction zone, most probably in a continental arc setting, as suggested by numerous microdioritic enclaves. Zircon cores record a spread of ages between 609 and 548 Ma and define an age peak at c. 590 Ma, interpreted as the most likely emplacement age of the granodioritic protolith. This Ediacaran population shows a consistent zircon Th/U ratio (similar to 0.5) which likely indicates long-lived magmatic activity in a continental arc setting and corroborates our geochemical interpretations. The zircon overgrowth rims give ages from 505 to 460 Ma and might be of metamorphic origin (lower Th/U ratios), related to an important tectonothermal event that developed during Lower to Middle Ordovician times. The occurrence of older zircon grains (c. 1000 Ma and c. 1800-2500 Ma), either inherited from a crustal source or incorporated from country rocks during magma ascent, provides some constraints on the paleoposition of the magmatic arc, likely situated on the eastern shelf of the northern Gondwana margin.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

V - Vyzkumna aktivita podporovana z jinych verejnych zdroju

Rok uplatnění

2023

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

International Journal of Earth Sciences

ISSN

1437-3254

e-ISSN

1437-3262

Svazek periodika

112

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

DE - Spolková republika Německo

Počet stran výsledku

26

Strana od-do

925-950

Kód UT WoS článku

000897489300001

EID výsledku v databázi Scopus

2-s2.0-85143621909