气候变化领域集成服务门户(CCPortal): Lithospheric architecture of a Phanerozoic orogen from magnetotellurics: AusLAMP in the Tasmanides, southeast Australia

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DOI	10.1016/j.tecto.2020.228560
	Lithospheric architecture of a Phanerozoic orogen from magnetotellurics: AusLAMP in the Tasmanides, southeast Australia
	Kirkby A.L.; Musgrave R.J.; Czarnota K.; Doublier M.P.; Duan J.; Cayley R.A.; Kyi D.
发表日期	2020
ISSN	00401951
卷号	793
英文摘要	We present a resistivity model of the southern Tasmanides of southeastern Australia using Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) data. Modelled lower crustal conductivity anomalies resemble concentric geometries revealed in the upper crust by potential field and passive seismic data. These geometries are a key part of the crustal architecture predicted by the Lachlan Orocline model for the evolution of the southern Tasmanides, in which the Proterozoic Selwyn Block drives oroclinal rotation against the eastern Gondwana margin during the Silurian period. For the first time, we image these structures in three dimensions (3D) and show they persist below the Moho. These include a lower crustal conductor largely following the northern Selwyn Block margin. Spatial association between lower crustal conductors and both Paleozoic to Cenozoic mafic to intermediate alkaline volcanism and gold deposits suggests a genetic association i.e. fluid flow into the lower crust resulting in the deposition of conductive phases such as hydrogen, iron, sulphides and/or graphite. The 3D model resolves a different pattern of conductors in the lithospheric mantle, including northeast trending anomalies in the northern part of the model. Three of these conductors correspond to Cenozoic leucitite volcanoes along the Cosgrove mantle hotspot track which likely map the metasomatised mantle source region of these volcanoes. The northeasterly alignment of the conductors correlates with variations in the lithosphere-asthenosphere boundary (LAB) and the direction of Australian plate movement, and may be related to movement of an irregular LAB topography over the asthenosphere. By revealing the tectonic architecture of a Phanerozoic orogen and the overprint of more recent tectono-magmatic events, our resistivity model enhances our understanding of the lithospheric architecture and geodynamic processes in southeast Australia, demonstrating the ability of magnetotelluric data to image geological processes over time. © 2020
关键词	AusLAMP Magnetotellurics Orogen Resistivity Tasmanides Tectonics
英文关键词	Architecture; Digital storage; Flow of fluids; Geodynamics; Gold deposits; Image enhancement; Iron compounds; Iron deposits; Magnetotellurics; Seismology; Structural geology; Sulfur compounds; Topography; Volcanoes; Conductivity anomalies; Lithosphere-asthenosphere boundary; Magnetotelluric data; Mantle source region; Resistivity modeling; South-eastern Australia; Southeast australia; Spatial associations; 3D modeling; crustal structure; electrical conductivity; geodynamics; lithospheric structure; magnetotelluric method; orogeny; Phanerozoic; structural geology; tectonic setting; volcanism; Australia
语种	英语
来源期刊	Tectonophysics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/207793
作者单位	Geoscience Australia, ACT, Canberra, 2601, Australia; Geological Survey of New South Wales, 516 High Street, Maitland, NSW 2320, Australia; Geological Survey of Victoria, 1 Spring Street, Vic, Melbourne, 3000, Australia
推荐引用方式 GB/T 7714	Kirkby A.L.,Musgrave R.J.,Czarnota K.,et al. Lithospheric architecture of a Phanerozoic orogen from magnetotellurics: AusLAMP in the Tasmanides, southeast Australia[J],2020,793.
APA	Kirkby A.L..,Musgrave R.J..,Czarnota K..,Doublier M.P..,Duan J..,...&Kyi D..(2020).Lithospheric architecture of a Phanerozoic orogen from magnetotellurics: AusLAMP in the Tasmanides, southeast Australia.Tectonophysics,793.
MLA	Kirkby A.L.,et al."Lithospheric architecture of a Phanerozoic orogen from magnetotellurics: AusLAMP in the Tasmanides, southeast Australia".Tectonophysics 793(2020).