Carboniferous mafic-ultramafic intrusions in the Eastern Pontides (Pulur Complex)

• Verfasst von: Topuz, Gültekin [VerfasserIn]
• Verfasst von: Altherr, Rainer [VerfasserIn]
• Verfasst von: Candan, Osman [VerfasserIn]
• Verfasst von: Wang, Jia-Min [VerfasserIn]
• Verfasst von: Okay, Aral I. [VerfasserIn]
• Verfasst von: Wu, Fu-Yuan [VerfasserIn]
• Verfasst von: Ergen, Ali [VerfasserIn]
• Verfasst von: Zack, Thomas [VerfasserIn]
• Verfasst von: Siebel, Wolfgang [VerfasserIn]
• Verfasst von: Shangh, Cosmas K. [VerfasserIn]
• Verfasst von: Schwarz, Winfried H. [VerfasserIn]
• Verfasst von: Meyer, Hans-Peter [VerfasserIn]
• Verfasst von: Satır, Muharrem [VerfasserIn]
• Titel: Carboniferous mafic-ultramafic intrusions in the Eastern Pontides (Pulur Complex)
• Titelzusatz: implications for the source of coeval voluminous granites
• Verf.angabe: Gültekin Topuz, Rainer Altherr, Osman Candan, Jia-Min Wang, Aral I. Okay, Fu-Yuan Wu, Ali Ergen, Thomas Zack, Wolfgang Siebel, Cosmas K. Shangh, Winfried H. Schwarz, Hans-Peter Meyer, Muharrem Satır
• E-Jahr: 2023
• Jahr: January 2023
• Umfang: 17 S.
• Illustrationen: Illustrationen
• Fussnoten: Online verfügbar: 18. November 2022, Artikelversion: 24. November 2022 ; Gesehen am 15.08.2023
• Titel Quelle: Enthalten in: Lithos
• Ort Quelle: Amsterdam [u.a.] : Elsevier Science, 1968
• Jahr Quelle: 2023
• Band/Heft Quelle: 436-437(2023) vom: Jan., Artikel-ID 106946, Seite 1-17
• ISSN Quelle: 1872-6143
• DOI: doi:10.1016/j.lithos.2022.106946
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: Cumulate rock
• Sach-SW: High-K calc-alkaline granite
• Sach-SW: High-volume magmatism
• Sach-SW: Isotopic dating
• Sach-SW: Mafic-ultramafic intrusion
• Sach-SW: Sakarya Zone, Turkey
• Sach-SW: Variscan orogeny, Pulur
• K10plus-PPN: 1856167550

Abstract

This study deals with the age and petrogenesis of mafic-ultramafic intrusions ranging in size from a few meters to 10 km within the Early Carboniferous high-grade gneisses of the Pulur Complex in the Eastern Pontides. The intrusions comprise dunite, wehrlite, gabbronorite, leucogabbro, anorthosite and ilmenite-bearing gabbronorite of cumulus origin, and are crosscut by dikes of ilmenite-bearing gabbronorite, leucogranite and microdiorite. U-Pb dating on zircons from gabbronorite, anorthosite and leucogranite yielded igneous crystallization ages of 322-326 Ma, indicating that the intrusions were emplaced ca. 5-7 Ma after the peak of high-grade metamorphism, and form part of the Late Carboniferous high-volume magmatism in the region. In most cumulate rocks, Cr-Al spinel, olivine and plagioclase were early crystallizing phases, followed by orthopyroxene, clinopyroxene and hornblende. Whole rock geochemical data suggest that wehrlite, gabbronorite, leucogabbro and anorthosite stem from a common magma, and ilmenite-bearing gabbronorite and dikes of leucogranite and microdiorite from different magmas. Application of mineral/melt partition coefficients to trace element compositions of clinopyroxene and hornblende in cumulate rocks suggests that the main cumulate body was derived from middle- to high-K calc-alkaline basic melts, and relatively late ilmenite-bearing gabbronorites from hypersthene-normative Ca-rich melts. All the rock types display radiogenic Sr and Pb isotopic signatures, and unradiogenic Nd isotopic ratios, which are indistinguishable from those of the coeval voluminous high-K calc-alkaline I-type granites in the region; the isotopic ratios are probably related to the metasomatism of the lithospheric mantle by sediment-derived melts. We suggest that the parental melts of the mafic-ultramafic intrusions and those of the high-K calc-alkaline granites were genetically related, and melts of the high-K calc-alkaline granites were probably derived from the melting of newly underplated calc-alkaline basic material at lower crustal depths, that were compositionally comparable to the parental magmas of the mafic-ultramafic intrusions.