Geochemical and geochronological evidence for a Middle Permian oceanic plateau fragment in the Paleo-Tethyan suture zone of NE Iran
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F18%3A00000132" target="_blank" >RIV/00025798:_____/18:00000132 - isvavai.cz</a>
Alternative codes found
RIV/67985831:_____/18:00500254
Result on the web
<a href="http://dx.doi.org/10.1007/s00410-018-1506-x" target="_blank" >http://dx.doi.org/10.1007/s00410-018-1506-x</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1007/s00410-018-1506-x" target="_blank" >10.1007/s00410-018-1506-x</a>
Alternative languages
Result language
angličtina
Original language name
Geochemical and geochronological evidence for a Middle Permian oceanic plateau fragment in the Paleo-Tethyan suture zone of NE Iran
Original language description
The mafic–ultramafic Fariman complex in northeastern Iran has been interpreted as a Paleo-Tethyan ophiolitic fragment with subduction- and plume-related characteristics as well as a basin deposit on an active continental margin. Contributing to this issue, we present geochemical, geochronological, and mineralogical data for transitional and tholeiitic basalts. Thermodynamic modeling suggests picritic parental magmas with 16–21 wtpercent MgO formed at plume-like mantle potential temperatures of ca. 1460–1600 °C. Rare pyroxene spinifex textures and skeletal to feather-like clinopyroxene attest to crystallization from undercooled magma and high cooling rates. Chromium numbers and TiO2 concentrations in spinel are similar to those in intraplate basalts. 40Ar–39Ar dating of magmatic hornblende yielded a plateau age of 276 ± 4 Ma (2sigma). Transitional basalt with OIB-like trace element characteristics is the predominant rock-type; less frequent are tholeiitic basalts with mildly LREE depleted patterns and picrites with intermediate trace element characteristics. All samples show MORB-OIB like Pb/Ce, Th/La, and Th/Nb ratios which preclude subduction-modified mantle sources and felsic crustal material. Tholeiitic basalts and related olivine cumulate rocks show MORB-like initial epsilonNd values of + 9.4 to + 6.2 which define a mixing linewith the data for the transitional basalts (epsilonNd ca. + 2.6). Initial 187Os/188Os ratios of 0.124–0.293 support mixed sources with a high proportion of recycled mafic crust in the transitional basalts. High concentrations of highly siderophile elements are in agreement with the high mantle potential temperatures and inferred high-melting degrees. It is argued that the Fariman complex originated by melting of a mantle plume component as represented by the OIB-like transitional basalt and entrained asthenosphere predominant in the MORB-like tholeiites. Two lines of evidence such as association of the Fariman complex with pelagic to neritic sedimentary rocks and the tectonic position at the boundary of two continental blocks defined by ophiolites and accretionary complexes of different ages suggest formation in an oceanic domain. Thus, we interpret it as a fragment of an oceanic plateau, which escaped subduction and was accreted as exotic block in the Paleo-Tethyan suture zone
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
—
Continuities
V - Vyzkumna aktivita podporovana z jinych verejnych zdroju
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
Contributions to Mineralogy and Petrology
ISSN
0010-7999
e-ISSN
—
Volume of the periodical
173
Issue of the periodical within the volume
10: 81
Country of publishing house
DE - GERMANY
Number of pages
23
Pages from-to
nestránkováno
UT code for WoS article
000444449500001
EID of the result in the Scopus database
2-s2.0-85053204608