Paleogeography of the Gondwana passive margin fragments involved in the Variscan and Alpine collisions: Perspectives from metavolcanic-sedimentary basement of the Western Carpathians

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F24%3A10169042" target="_blank" >RIV/00025798:_____/24:10169042 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.earscirev.2024.104763" target="_blank" >https://doi.org/10.1016/j.earscirev.2024.104763</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.earscirev.2024.104763" target="_blank" >10.1016/j.earscirev.2024.104763</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Paleogeography of the Gondwana passive margin fragments involved in the Variscan and Alpine collisions: Perspectives from metavolcanic-sedimentary basement of the Western Carpathians

Popis výsledku v původním jazyce

The general configuration of the main continental blocks in the Gondwana supercontinent and the Ediacaran-early Paleozoic tectonic evolution of its northern margin are widely accepted. However, reconstruction of theoriginal positions and the question of potential separation of the Gondwana-derived crustal segments that arenow included in the Variscan and Alpine orogenic belts remain controversial. The Western Carpathians, part ofthe Alpine-Carpathian belt, represents an important crustal segment broken-off from northern Gondwana andlater incorporated into both the Variscan and Alpine collisional orogens. The earliest tectonic evolution andpaleogeography of the pre-Variscan basement of the Western Carpathians remains poorly known, due to insufficientage data and intense polyphase tectonometamorphic overprints, both Variscan and Alpine. This paperprovides new results of U-Pb dating and Hf isotopic analysis of detrital zircons as well as a whole-rockgeochemical study from metavolcanic-sedimentary basement units of the Western Carpathians. The obtainedage spectra suggest that the sedimentary succession was supplied dominantly by Ediacaran (c. 600 Ma) zircons,with a relatively minor role for Stenian-Tonian (c. 1.2-0.9 Ga) and Paleoproterozoic cratonic (c. 2.2-1.8 Ga)zircons. The mixed Hf isotopic signature (εHf(t) values ranging from ????20 to +12) of the Ediacaran zircons indicatessubstantial mixing of mantle-derived magmas with mature crustal material, typical of continentalmagmatic arcs. In contrast, the mostly negative εHf(t) values (????15 to +4) of the cratonic zircons suggest recyclingof an older continental crust. The presumably youngest part of the sequence is also characterised by high proportionof early Paleozoic zircons with generally negative εHf(t) values (????10 to ????2). The zircon U-Pb age spectra,Hf isotopic patterns and whole-rock geochemical signatures of the studied Western Carpathians sequences areinterpreted as reflecting deposition at a progressively developing Cambrian-Silurian passive margin setting. TheWest Carpathian data have been correlated with a comprehensive detrital zircon U-Pb age and Hf isotope dataset compiled from possible source areas and other Gondwana-derived units to test the possibility of their primarylinkages. These correlations indicate strong similarity in both zircon U-Pb age spectra and Hf isotopic compositionsto other parts of the Ediacaran (Cadomian) continental magmatic arc. Older, cratonic sources are linked tothe Saharan or East African parts of northern Gondwana, whereas the early Paleozoic detritus must represent alocal volcanic source. Taken together, our new data from the Western Carpathians provide constraints for a newpaleogeographic model of the northern African part of the Gondwana passive margin.

Název v anglickém jazyce

Paleogeography of the Gondwana passive margin fragments involved in the Variscan and Alpine collisions: Perspectives from metavolcanic-sedimentary basement of the Western Carpathians

Popis výsledku anglicky

The general configuration of the main continental blocks in the Gondwana supercontinent and the Ediacaran-early Paleozoic tectonic evolution of its northern margin are widely accepted. However, reconstruction of theoriginal positions and the question of potential separation of the Gondwana-derived crustal segments that arenow included in the Variscan and Alpine orogenic belts remain controversial. The Western Carpathians, part ofthe Alpine-Carpathian belt, represents an important crustal segment broken-off from northern Gondwana andlater incorporated into both the Variscan and Alpine collisional orogens. The earliest tectonic evolution andpaleogeography of the pre-Variscan basement of the Western Carpathians remains poorly known, due to insufficientage data and intense polyphase tectonometamorphic overprints, both Variscan and Alpine. This paperprovides new results of U-Pb dating and Hf isotopic analysis of detrital zircons as well as a whole-rockgeochemical study from metavolcanic-sedimentary basement units of the Western Carpathians. The obtainedage spectra suggest that the sedimentary succession was supplied dominantly by Ediacaran (c. 600 Ma) zircons,with a relatively minor role for Stenian-Tonian (c. 1.2-0.9 Ga) and Paleoproterozoic cratonic (c. 2.2-1.8 Ga)zircons. The mixed Hf isotopic signature (εHf(t) values ranging from ????20 to +12) of the Ediacaran zircons indicatessubstantial mixing of mantle-derived magmas with mature crustal material, typical of continentalmagmatic arcs. In contrast, the mostly negative εHf(t) values (????15 to +4) of the cratonic zircons suggest recyclingof an older continental crust. The presumably youngest part of the sequence is also characterised by high proportionof early Paleozoic zircons with generally negative εHf(t) values (????10 to ????2). The zircon U-Pb age spectra,Hf isotopic patterns and whole-rock geochemical signatures of the studied Western Carpathians sequences areinterpreted as reflecting deposition at a progressively developing Cambrian-Silurian passive margin setting. TheWest Carpathian data have been correlated with a comprehensive detrital zircon U-Pb age and Hf isotope dataset compiled from possible source areas and other Gondwana-derived units to test the possibility of their primarylinkages. These correlations indicate strong similarity in both zircon U-Pb age spectra and Hf isotopic compositionsto other parts of the Ediacaran (Cadomian) continental magmatic arc. Older, cratonic sources are linked tothe Saharan or East African parts of northern Gondwana, whereas the early Paleozoic detritus must represent alocal volcanic source. Taken together, our new data from the Western Carpathians provide constraints for a newpaleogeographic model of the northern African part of the Gondwana passive margin.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA24-12999S" target="_blank" >GA24-12999S: Geochronologická studie pre až synkolizních devonských pánví variského orogenního pásu</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Earth-Science Reviews

ISSN

0012-8252

e-ISSN

1872-616X

Svazek periodika

2024

Číslo periodika v rámci svazku

253

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

28

Strana od-do

1-28

Kód UT WoS článku

001230462600001

EID výsledku v databázi Scopus

2-s2.0-85190348638