Cambrian–Ordovician magmatism of the Ikh-Mongol Arc System exemplified by the Khantaishir Magmatic Complex (Lake Zone, south-central Mongolia)
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F18%3A00000011" target="_blank" >RIV/00025798:_____/18:00000011 - isvavai.cz</a>
Alternative codes found
RIV/00216208:11310/18:10377880
Result on the web
<a href="http://dx.doi.org/10.1016/j.gr.2017.10.003" target="_blank" >http://dx.doi.org/10.1016/j.gr.2017.10.003</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.gr.2017.10.003" target="_blank" >10.1016/j.gr.2017.10.003</a>
Alternative languages
Result language
angličtina
Original language name
Cambrian–Ordovician magmatism of the Ikh-Mongol Arc System exemplified by the Khantaishir Magmatic Complex (Lake Zone, south-central Mongolia)
Original language description
The Khantaishir Magmatic Complex (KMC) (south–central Mongolia) exposes a section of a magmatic system consisting of deep crustal, ultramafic cumulates (Amp gabbros and hornblendites; c. 0.35–0.5 GPa) to shallower crustal levels dominated by Amp–Bt tonalites (c. 0.1–0.2 GPa). The magmatic rocks were emplaced during most of the Cambrian (c. 538–495 Ma) and are mostly geochemically primitive (Mg# ~50), Na-rich and metaluminous. The (normal-) calc-alkaline signature and characteristic trace-element enrichment in hydrous-fluid mobile large-ion lithophile elements (LILE) relative to high-field strength elements (HFSE) suggest an origin within a magmatic arc. Multiple intrusions of basic magma derived from a subduction-modified depleted mantle developed by fractional crystallization and/or accumulation of (Ol, Cpx) Amp + Bt, later joined by Pl. Magma mixing with, or without, exchange of xenocrysts between compositionally dissimilar melt batches was also important. Over time, partial melting of older, lower crustal metabasic rocks became increasingly significant, again with a strong subduction signature. The lack of zircon inheritance in the magmatic products and rather high zircon EpsHf(t) values (all >+3, but for most samples > +8) as well as whole-rock Sr–Nd isotopic compositions imply that the arc was not founded on mature continental crust. It was probably located at the margin of the Baydrag microcontinent, dominated by accreted metabasic rocks of an older (early Tonian?) island arc covered by a thin layer of subordinate metasediments containing detrital zircons with Tonian and ill-defined Palaeoproterozoic ages. The KMC represents a vestige of an extensive Cambrian–Ordovician subduction system (termed here the Ikh-Mongol Arc System), bordering the western margin of a chain of Precambrian microcontinents (Tuva-Mongolia, Zabkhan and Baydrag) that, together with accreted Neoproterozoic marginal basins (the Lake Zone), defines the external part of the Mongolian orocline.
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/GA17-17540S" target="_blank" >GA17-17540S: Contrasting mechanisms of formation of the Pangea supercotinent: new insights into formation of continental crust</a><br>
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Others
Publication year
2018
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
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Volume of the periodical
54
Issue of the periodical within the volume
February
Country of publishing house
NL - THE KINGDOM OF THE NETHERLANDS
Number of pages
28
Pages from-to
122-149
UT code for WoS article
000428481300008
EID of the result in the Scopus database
2-s2.0-85033607608