Eclogite subduction wedge intruded by arc-type magma: The earliest record of Variscan arc in the Bohemian Massif
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F21%3A00000084" target="_blank" >RIV/00025798:_____/21:00000084 - isvavai.cz</a>
Alternative codes found
RIV/00216208:11310/21:10435364
Result on the web
<a href="https://www.sciencedirect.com/science/article/pii/S1342937X21002082#gp005" target="_blank" >https://www.sciencedirect.com/science/article/pii/S1342937X21002082#gp005</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.gr.2021.07.005" target="_blank" >10.1016/j.gr.2021.07.005</a>
Alternative languages
Result language
angličtina
Original language name
Eclogite subduction wedge intruded by arc-type magma: The earliest record of Variscan arc in the Bohemian Massif
Original language description
Previously unrecognized mafic and felsic plutonic rocks, formerly interpreted as an anatectic part of the amphibolite-eclogite Mariánské Lázně Complex (MLC, Bohemian Massif) were examined together with a possible upper-crustal equivalent represented by the Čistá pluton intruding continental crust farther east. These plutonic rocks were studied by whole-rock geochemistry (major and trace elements, Sr-Nd isotopes) and zircon U-Pb geochronology. The MLC magmatic rocks range from pyroxene-amphibole gabbro to trondhjemite and oligoclasite. The Čistá pluton consists of porphyritic granitoids. The calc-alkaline nature of these rocks, relative enrichment of fluid-mobile elements (including large-ion lithophile elements), strong fractionation of light rare earth elements over heavy rare earth elements and depletion of high field strength elements are evidence for active margin magmatism. U-Pb zircon dating indicates that the magmatism was Mid-Devonian in both the MLC (ca. 385 Ma) and Čistá pluton (ca. 390 up to ca. 365 Ma). Both magmatic units show inherited cores probably linked to recycling of crustal material. Sr-Nd isotopic compositions indicate that the gabbro formed from a depleted MORB mantle source composition with a small contribution of a subduction and crustal component. A three-stage geodynamic model is proposed: 1) ca. 390–380 Ma recycling of a high-pressure accretionary wedge and migration of arc melts into more distal parts of the upper continental plate, 2) ca. 380–370 Ma compression and thickening of the accretionary wedge-arc edifice, and 3) ca. 370–365 Ma development of a giant east-dipping detachment that reworked the whole edifice in the west and also involved emplacement of the supracrustal Čistá pluton along antithetic west-dipping shear zone in the east. The studied magmatic rocks record a Mid-Devonian magmatic arc related to the formation of a subduction wedge stacked beneath the upper plate that was followed by formation of a second and independent Carboniferous continental arc further east.
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
<a href="/en/project/GA17-22207S" target="_blank" >GA17-22207S: The role of inherited continental margin architecture on early Variscan convergence</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2021
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Gondwana research
ISSN
1342-937X
e-ISSN
—
Volume of the periodical
99
Issue of the periodical within the volume
November
Country of publishing house
NL - THE KINGDOM OF THE NETHERLANDS
Number of pages
27
Pages from-to
220-246
UT code for WoS article
000709515300003
EID of the result in the Scopus database
2-s2.0-85111944547