Sources and petrogenesis of Jurassic granitoids in the Yusufeli area,   Northeastern Turkey: Implications for pre- and post-collisional   lithospheric thinning of the eastern Pontides

doi:10.1016/j.tecto.2009.10.009

CORC > 北京大学 > 地球与空间科学学院

	Sources and petrogenesis of Jurassic granitoids in the Yusufeli area, Northeastern Turkey: Implications for pre- and post-collisional lithospheric thinning of the eastern Pontides
	Dokuz, Abdurrahman ; Karsli, Orhan ; Chen, Bin ; Uysal, Ibrahim
刊名	tectonophysics
	2010
关键词	Jurassic granitoids Lithospheric thinning Slab breakoff The eastern Pontides Turkey IN-HORNBLENDE BAROMETER NE TURKEY CALC-ALKALINE LOWER CRUST NORTHERN TURKEY TECTONIC EVOLUTION CONTINENTAL-MARGIN MAGMA INTERACTION CENTRAL ANATOLIA SLAB BREAKOFF
DOI	10.1016/j.tecto.2009.10.009
英文摘要	Small granitoids emplaced into the early Jurassic volcani-clastic succession in the Yusufeli area, northeastern Turkey, can be temporally and geochemically classified into two groups: early Jurassic low-K and late Jurassic high-K. (40)Ar-(39)Ar hornblende analyses yielded 188.0 +/- 4.3 Ma for the Dutlupinar intrusion, dating the subduction related rifting in the region. It comprises metaluminous to weakly peraluminous (ASI = 0.94-1.11) granodiorite and, to a lesser extent, tonalite whose K(2)O-poor (<2.04 wt.%) nature and weak negative Eu anomalies (Eu/Eu* = 0.9-0.7) preclude derivation by fractional crystallization from a K-rich melt. Sr, Nd and Pb isotopic data reveal derivation by partial melting from an already cooled tholeiitic basic rocks which had mantle-like isotope signature. The Sumbated intrusion formed in the late Jurassic (153.0 +/- 3.4 Ma) and consists chiefly of metaluminous (ASI=0.84-0.99) quartz monzodiorite. Medium to high-K(2)O, relatively high MgO and Sr contents, flat HREE patterns without prominent Eu anomalies, slightly positive epsilon(Nd)(t) values (+1.5 to +2.5) and low I(sr) ratios (0.7046-0.7056) are consistent with an origin by dehydration melting of a juvenile source, above the garnet stability field, dominated by likely K-amphibole bearing calc-alkaline mafic rocks. Geochemical data show that fractional crystallization from a Sumbated-like quartz monzodioritic magma is the fundamental process responsible for the evolved compositional range of the Kecikaya intrusion. The geochemical and geochronological data presented here indicate that the late Jurassic magmatism occurred in a post-collisional setting. Slab-breakoff, which was followed by shortly after collision, seems to be the most plausible mechanism for the generation of medium to high-K calc-alkaline rocks of the Sumbated and the Kecikaya intrusions, indicating a switch in the geodynamic setting, e.g., from pre-collision to post-collision in the middle Jurassic in the eastern Pontides. (c) 2009 Elsevier B.V. All rights reserved.; Geochemistry & Geophysics; SCI(E); EI; 0; ARTICLE; 1-4; 259-279; 480
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/245562]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Dokuz, Abdurrahman,Karsli, Orhan,Chen, Bin,et al. Sources and petrogenesis of Jurassic granitoids in the Yusufeli area, Northeastern Turkey: Implications for pre- and post-collisional lithospheric thinning of the eastern Pontides[J]. tectonophysics,2010.
APA	Dokuz, Abdurrahman,Karsli, Orhan,Chen, Bin,&Uysal, Ibrahim.(2010).Sources and petrogenesis of Jurassic granitoids in the Yusufeli area, Northeastern Turkey: Implications for pre- and post-collisional lithospheric thinning of the eastern Pontides.tectonophysics.
MLA	Dokuz, Abdurrahman,et al."Sources and petrogenesis of Jurassic granitoids in the Yusufeli area, Northeastern Turkey: Implications for pre- and post-collisional lithospheric thinning of the eastern Pontides".tectonophysics (2010).