Variscan granitic magmatism in the Western Carpathians with linkage to slab break-off

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F22%3A00552094" target="_blank" >RIV/67985831:_____/22:00552094 - isvavai.cz</a>

Result on the web

<a href="https://www.sciencedirect.com/science/article/pii/S0024493721006320" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0024493721006320</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.lithos.2021.106589" target="_blank" >10.1016/j.lithos.2021.106589</a>

Result language

angličtina

Original language name

Variscan granitic magmatism in the Western Carpathians with linkage to slab break-off

Original language description

The Variscan basement within the Western Carpathian Alpine architecture generally consists of metaluminous/peraluminous tonalite/granodiorite massifs and high-grade metamorphic complexes of metapelites, metaultramafites, and metabasites with relics of eclogites. Unfortunately, the Variscan crystalline basement of the Western Carpathians is only fragmentally exposed. Therefore, the proposed geodynamic evolutionary model for the Variscan granites of the Western Carpathians is primarily based on granite data from the Mal´a Fatra Mts. with additional dating from the High Tatra Mts. The oldest magmatic age of 362 ± 4 Ma in the Mal´a Fatra horst was recorded in diatexites from a high-grade metamorphic complex, which is related to crustal anatexis during Variscan subduction. Subsequent collisional event and break-off of the subducted slab promoted exhumation of the diatexites within the high grade metamorphic complex and intrusion of 353 ± 3 Ma old Tournaisian tonalite. Intensive heat input after slab break-off from the rising asthenosphere generated melting of the lower crust and extensive calc-alkaline, Mg-rich granitic magmatism in a short time span from 347 ± 4 to 342 ± 3 Ma. These Visean granitic rocks caused thermal overprint on the roof metamorphic rocks, including diatexites and Tournaisian tonalites at ca. 348 ± 5.6 to 342 ± 3 Ma. The Visean granite formation was controlled by the mixing of hot magmas, which is indicated by the presence of composite oligoclase/andesine plagioclase with preserved labradorite cores, alkali feldspars with Na2O ≥ 2 wt%, zoned apatite, the presence of antiperthite, and quartz ocelli. Elevated contents of mantle-derived elements like V, Ni, Cr, Ba, high Sr/Y ratio of ~44, steep LREE and flat HREE segments of chondrite-normalised patterns document adakite-like feature of the investigated granitic rocks which resulted from melting of a mixed lower-crustal and mantle sources and crystallisation in the presence of garnet. Unusual abundance of Fe–Ti oxides in granodiorites with magmatic cooling temperatures of 735–756 ◦C supports high-T input from mantle. In the High Tatra Mts., diorite xenolith shows the age of 359.2 ± 3 Ma, and its host granodiorite the age of 350.1 ± 2.6 Ma. The diorite contains acicular zircons, which points to rapid exhumation. Stubby zircon of the host granodiorite shows regular, oscillatory zoning controlled by a gradual temperature decrease. The non-comagmatic relationships between diorite and host granodiorite are indicated also by a difference in zircon Th/U ratio, which is 0.2 for the host granodiorite, but 1.0 for the diorite on average. The presented data show that slab break-off could have been a mechanism that promoted Variscan granitic magmatism in the Western Carpathians.

Czech name

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Czech description

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Type

J_imp - 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

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

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

Name of the periodical

Lithos

ISSN

0024-4937

e-ISSN

1872-6143

Volume of the periodical

412-413

Issue of the periodical within the volume

March

Country of publishing house

NL - THE KINGDOM OF THE NETHERLANDS

Number of pages

15

Pages from-to

106589

UT code for WoS article

000762441100001

EID of the result in the Scopus database

2-s2.0-85122698712