DOI: 10.1016/j.epsl.2020.116355
论文题名: Paired metamorphism in the Neoarchean: A record of accretionary-to-collisional orogenesis in the North China Craton
作者: Huang B. ; Kusky T.M. ; Johnson T.E. ; Wilde S.A. ; Wang L. ; Polat A. ; Fu D.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2020
卷: 543 语种: 英语
中文关键词: Archean
; Dengfeng Complex
; North China Craton
; paired metamorphism
; plate tectonics
英文关键词: Garnets
; Geochronology
; Metamorphic rocks
; Mica
; Plates (structural components)
; Thermal gradients
; Zircon
; Accretionary complex
; Collisional orogenesis
; Continent collisions
; Metamorphic belts
; North China Craton
; Oceanic subduction
; Paleoproterozoic
; Phase equilibriums
; Gallium compounds
; accretionary prism
; collision zone
; convergent margin
; igneous intrusion
; metamorphism
; orogeny
; petrography
; spatiotemporal analysis
; subduction zone
; China
; North China Block
英文摘要: Paired metamorphism is the hallmark of asymmetric subduction at Phanerozoic convergent plate margins, yet spatially and temporally linked paired metamorphic belts have rarely been documented in the Archean rock record. Here, we investigate the Neoarchean Dengfeng Complex, a typical granite–greenstone belt in the southern part of the North China Craton (NCC). Using petrography, geochronology, and phase equilibrium constraints on rocks from different lithostructural units, we suggest the ca. 2.54–2.50-Ga Dengfeng Complex represents a remnant of a spatially and temporally linked Neoarchean paired metamorphic belt. In the western part of the complex, a garnet amphibolite from a dominantly metabasic unit (MBU) records near peak P–T conditions of 6.3–10 kbar and ∼675–750 °C, corresponding to a high thermobaric ratio (T/P) of ∼720–1200 °C/GPa. Tonalite–trondhjemite–granodiorite (TTG) gneisses preserve evidence for partial melting, also consistent with relatively high T/P (∼875–1400 °C/GPa). In the eastern part of the Dengfeng Complex, two garnet amphibolites and three garnet quartz–mica schists from a dominantly metasedimentary unit (MSU) record peak P–T conditions of >9.8 kbar and ∼525–655 °C, corresponding to intermediate thermobaric ratios of ∼425–600 °C/GPa. Zircon and titanite U–Pb dating, coupled with existing ages of post-kinematic intrusions, constrain the metamorphic age to ca. 2.52–2.50 Ga. The metamorphic P–T data indicate that the MSU was buried to >30 km then exhumed to the near-surface by the early Paleoproterozoic. Our metamorphic results, when combined with recent structural and geochemical data, suggest the Dengfeng Complex records Neoarchean paired metamorphism, in which the higher thermal gradients reflect the arc–forearc region and the lower thermal gradients correspond to the accretionary complex. Our data indicate that the southern NCC experienced accretionary-to-collisional orogenesis with intra-oceanic subduction, forearc accretion (ca. 2.54–2.50 Ga), and subsequent arc–continent collision (ca. 2.50–2.47 Ga). The recognition of paired metamorphism in the NCC is consistent with widespread subduction and the operation of a plate tectonic regime in the late Archean. © 2020 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165036
Appears in Collections: 气候变化与战略
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作者单位: Center for Global Tectonics, School of Earth Sciences, State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan, 430074, China; Three Gorges Research Center for Geo-hazards, China University of Geosciences, Wuhan, 430074, China; School of Earth and Planetary Sciences, Curtin University, Perth, 6845, Australia; School of the Environment, University of Windsor, Windsor, ON N9B 3P4, Canada
Recommended Citation:
Huang B.,Kusky T.M.,Johnson T.E.,et al. Paired metamorphism in the Neoarchean: A record of accretionary-to-collisional orogenesis in the North China Craton[J]. Earth and Planetary Science Letters,2020-01-01,543