DOI: 10.1007/s00531-013-0918-0
论文题名: Geochemistry and geochronology of meta-igneous rocks from the Tokat Massif, north-central Turkey: Implications for Tethyan reconstructions
作者: Catlos E.J. ; Huber K. ; Shin T.A.
刊名: International Journal of Earth Sciences
出版年: 2013
卷: 102, 期: 8 起始页码: 2175
结束页码: 2198
语种: 英语
英文关键词: Baddeleyite
; Geochronology
; Karakaya Complex
; Laurasia
; Paleo-Tethys
; Zircon
Scopus关键词: deformation mechanism
; geochemistry
; geochronology
; island arc
; metagabbro
; metaigneous rock
; paleoceanography
; paleoenvironment
; Permian-Triassic boundary
; point source
; reconstruction
; spreading center
; uranium-lead dating
; Tokat Massif
; Turkey
英文摘要: Located in the eastern Pontides of the Sakarya Zone in north-central Turkey, the Tokat Massif records the closure of both the Paleo-Tethyan (Karakaya Complex) and Neo-Tethyan ocean basins. Meta-igneous samples collected from the region were studied to determine their sources and ages. We find significant geochemical differences between metagabbros of the Karakaya and Neo-Tethyan units in terms of their trace elements: Neo-Tethyan rocks are consistent with generation in an island arc setting, whereas Karakaya assemblages were likely generated in an oceanic spreading-center environment. Karakaya metagabbros also contain glaucophane, consistent with subduction subsequent to formation. Small (2-50 μm) zircon and baddeleyite grains from four Karakaya metagabbros were dated in thin section using an ion microprobe. The results demonstrate the reliability of the method to directly constrain the tectonomagmatic history of these types of assemblages. The rocks yield Late Permian/Early Triassic 238U/206Pb crystallization ages of 258 ± 14 Ma (±1σ, zircon) and 254 ± 8 Ma (±1σ, baddeleyite) and an Early Cretaceous minimum metamorphic age of 137 ± 8 Ma (±1σ, zircon). Some zircon grains and baddeleyite grains with zircon overgrowths yield Early to Middle Jurassic ages. Here we present a model in which metamorphism and deformation in this region occurred during northward subduction and closure of a Paleo-Tethyan ocean basin and accretion of the Karakaya units to the Laurasian continental margin. This was followed by the onset of closure of the Neo-Tethys during the Campanian-Paleocene and accretion of island arc units to the Tokat region. © 2013 Springer-Verlag Berlin Heidelberg. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885945636&doi=10.1007%2fs00531-013-0918-0&partnerID=40&md5=25a8ef6bfb0883e501998a13bdc05588
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70493
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Geological Sciences, Jackson School of Geosciences, University of Texas at Austin, 1 University Station C1100, Austin, TX, 78712-0254, United States; Statoil, 6300 Bridge Point Pkwy Building 2, Suite 500, Austin, TX, 78730, United States
Recommended Citation:
Catlos E.J.,Huber K.,Shin T.A.. Geochemistry and geochronology of meta-igneous rocks from the Tokat Massif, north-central Turkey: Implications for Tethyan reconstructions[J]. International Journal of Earth Sciences,2013-01-01,102(8)