DOI: 10.1016/j.tecto.2020.228375
论文题名: Regional-scale polydiapirism predating the Neoarchean Yilgarn Orogeny
作者: Zibra I. ; Lu Y. ; Clos F. ; Weinberg R.F. ; Peternell M. ; Wingate M.T.D. ; Prause M. ; Schiller M. ; Tilhac R.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2020
卷: 779 语种: 英语
中文关键词: Microstructures
; Quartz crystallographic preferred orientation
; Structural geology
; Tectonics
; Zircon isotopes
英文关键词: Domes
; Economic geology
; Granite
; Isotopes
; Kinematics
; Microstructure
; Silicate minerals
; Tectonics
; Zircon
; Continental crusts
; Crystallographic preferred orientations
; Evolutionary models
; Lithosphere dynamics
; Regional architectures
; Structural feature
; Structural pattern
; Zircon isotope
; Structural geology
; continental crust
; crustal structure
; diapirism
; isotopic composition
; microstructure
; structural geology
; tectonic setting
; zircon
; Australia
; Western Australia
; Yilgarn Block
英文摘要: Gneiss domes occur in a wide variety of orogenic and anorogenic domains of the continental crust, and play a major role in lithosphere dynamics by allowing upwards transfer of heat and mass. They commonly contain a core of granites and/or migmatites, overlain by a mantle of lower-grade rocks. Evolutionary models of many gneiss domes are controversial. Here we use new structural and zircon isotopic data to unravel the tectono-magmatic evolution of the Yalgoo dome and surroundings, at the margins of the Neoarchean Yilgarn Orogen, Western Australia. The study area includes at least seven granite–migmatite domes (5–70 km in average diameter), and several subdomes within the larger domes, all showing comparable structural features and age. In each dome, a concentric domal foliation is concordant with granite–greenstone contacts, bearing a radial, outward-plunging lineation. The bulk of the structures in each dome reflect magmatic flow, with pervasive subsolidus fabrics occurring only along the outer dome margins, and reflecting dome-up kinematics. Narrow greenstone keels pinched between domes and subdomes display vertical constriction, in an area regionally dominated by flattening along the steep sides of the deeply-eroded domes, and along the flat-laying dome roofs. The regional structural pattern and the kinematics of the high-strain zones are best explained by sequential emplacement of nested diapirs, which delivered large volumes of granitic magma in a c. 20 Myr time-span. The dome-and-keel regional architecture and the internal structures of each dome resulted therefore from multiscale polydiapirism. These diapirs were later weakly overprinted by a tectonic fabric that developed during the Neoarchean Yilgarn Orogeny. The contrast between the Yalgoo region and the rest of the craton, which was strongly reworked by this orogeny, highlights the dichotomy of tectonic styles in Archean terranes, demonstrating that diapirism dominated in times of tectonic quiescence. © 2020 Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170753
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Geological Survey of Western Australia, 100 Plain Street, East Perth, Western Australia 6004, Australia; School of Earth, Atmosphere and Environment, Monash University, Clayton, VIC 3800, Australia; Centre for Exploration Targeting and Australian Research Council Centre of Excellence for Core to Crust Fluid Systems (CCFS), School of Earth Sciences, The University of Western Australia, Crawley, WA 6009, Australia; Department of Earth Sciences, University of Gothenburg, Box 460, Gothenburg, 405 30, Sweden; Eberhard Karls Universität Tübingen Geschwister-Scholl-Platz, Tübingen, 72074, Germany; ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS) and GEMOC, Department of Earth and Planetary Sciences, Macquarie University, Sydney, NSW 2109, Australia
Recommended Citation:
Zibra I.,Lu Y.,Clos F.,et al. Regional-scale polydiapirism predating the Neoarchean Yilgarn Orogeny[J]. Tectonophysics,2020-01-01,779