Relative contributions of crust and mantle to generation of Campanian high-K calc-alkaline I-type granitoids in a subduction setting, with special reference to the Harsit Pluton, Eastern Turkey

Basit Öğe Kaydı
dc.authorid0000-0002-8091-1239
dc.contributor.authorKarsli, Orhan
dc.contributor.authorDokuz, Abdurrahman
dc.contributor.authorUysal, Ibrahim
dc.contributor.authorAydin, Faruk
dc.contributor.authorChen, Bin
dc.contributor.authorKandemir, Raif
dc.contributor.authorWijbrans, Jan
dc.date.accessioned2019-08-01T13:38:39Z
dc.date.available2019-08-01T13:38:39Z
dc.date.issued2010
dc.departmentNiğde ÖHÜ
dc.description.abstractWe present elemental and Sr-Nd-Pb isotopic data for the magmatic suite (similar to 79 Ma) of the Harsit pluton, from the Eastern Pontides (NE Turkey), with the aim of determining its magma source and geodynamic evolution. The pluton comprises granite, granodiorite, tonalite and minor diorite (SiO(2) = 59.43-76.95 wt%), with only minor gabbroic diorite mafic microgranular enclaves in composition (SiO(2) = 54.95-56.32 wt%), and exhibits low Mg# (<46). All samples show a high-K calc-alkaline differentiation trend and I-type features. The chondrite-normalized REE patterns are fractionated [(La/Yb)(n) = 2.40-12.44] and display weak Eu anomalies (Eu/Eu* = 0.30-0.76). The rocks are characterized by enrichment of LILE and depletion of HFSE. The Harsit host rocks have weak concave-upward REE patterns, suggesting that amphibole and garnet played a significant role in their generation during magma segregation. The host rocks and their enclaves are isotopically indistinguishable. Sr-Nd isotopic data for all of the samples display I(Sr) = 0.70676-0.70708, epsilon(Nd)(79 Ma) = -4.4 to -3.3, with T(DM) = 1.09-1.36 Ga. The lead isotopic ratios are ((206)Pb/(204)pb) = 18.79-18.87, ((207)Pb/(204)Pb) = 15.59-15.61 and ((208)Pb/(204)Pb) = 38.71-38.83. These geochemical data rule out pure crustal-derived magma genesis in a post-collision extensional stage and suggest mixed-origin magma generation in a subduction setting. The melting that generated these high-K granitoidic rocks may have resulted from the upper Cretaceous subduction of the Izmir-Ankara-Erzincan oceanic slab beneath the Eurasian block in the region. The back-arc extensional events would have caused melting of the enriched subcontinental lithospheric mantle and formed mafic magma. The underplating of the lower crust by mafic magmas would have played a significant role in the generation of high-K magma. Thus, a thermal anomaly induced by underplated basic magma into a hot crust would have caused partial melting in the lower part of the crust. In this scenario, the lithospheric mantle-derived basaltic melt first mixed with granitic magma of crustal origin at depth. Then, the melts, which subsequently underwent a fractional crystallization and crustal assimilation processes, could ascend to shallower crustal levels to generate a variety of rock types ranging from diorite to granite. Sr-Nd isotope modeling shows that the generation of these magmas involved similar to 65-75% of the lower crustal-derived melt and similar to 25-35% of subcontinental lithospheric mantle. Further, geochemical data and the Ar-Ar plateau age on hornblende, combined with regional studies, imply that the Harsit pluton formed in a subduction setting and that the back-arc extensional period started by least similar to 79 Ma in the Eastern Pontides.
dc.description.sponsorshipScientific and Technological Research Council of Turkey (TUBITAK) [107Y177, 108Y200]
dc.description.sponsorshipThis work was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) with grants # 107Y177 and 108Y200. The authors are also grateful to Durmus Boztug and Hakan Coban for their critical and constructive comments. Ahmet D. Sen and Murat Ketenci are thanked for their enthusiastic assistances during fieldwork.
dc.identifier.doi10.1007/s00410-010-0489-z
dc.identifier.endpage487
dc.identifier.issn0010-7999
dc.identifier.issue4
dc.identifier.scopus2-s2.0-77956401569
dc.identifier.scopusqualityQ1
dc.identifier.startpage467
dc.identifier.urihttps://dx.doi.org/10.1007/s00410-010-0489-z
dc.identifier.urihttps://hdl.handle.net/11480/4834
dc.identifier.volume160
dc.identifier.wosWOS:000282474000001
dc.identifier.wosqualityQ1
dc.indekslendigikaynakWeb of Science
dc.indekslendigikaynakScopus
dc.institutionauthor[0-Belirlenecek]
dc.language.isoen
dc.publisherSPRINGER
dc.relation.ispartofCONTRIBUTIONS TO MINERALOGY AND PETROLOGY
dc.relation.publicationcategoryMakale - Uluslararası Hakemli Dergi - Kurum Öğretim Elemanı
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.subjectEastern Turkey
dc.subjectHigh-K calc-alkaline granitoids
dc.subjectLower crustal melting
dc.subjectSubduction setting
dc.subjectBack-arc extension
dc.subjectRadiogenic isotopes
dc.titleRelative contributions of crust and mantle to generation of Campanian high-K calc-alkaline I-type granitoids in a subduction setting, with special reference to the Harsit Pluton, Eastern Turkey
dc.typeArticle

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