DOI: 10.1016/j.epsl.2018.09.033
Scopus记录号: 2-s2.0-85054599496
论文题名: Laterally Confined Volcanic Successions (LCVS); recording rift-jumps during the formation of magma-rich margins
作者: Norcliffe J.R. ; Paton D.A. ; Mortimer E.J. ; McCaig A.M. ; Nicholls H. ; Rodriguez K. ; Hodgson N. ; Van Der Spuy D.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 504 起始页码: 53
结束页码: 63
语种: 英语
英文关键词: rifting
; seaward dipping reflectors
; South Atlantic
; volcanic margin
Scopus关键词: Basalt
; Geometry
; Offshore oil well production
; Reflection
; Stratigraphy
; Continental break-up
; Large volumes
; Magmatic systems
; Rifted margins
; rifting
; South Atlantic
; Volcanic margin
; Volcanic successions
; Volcanoes
英文摘要: Seaward Dipping Reflectors (SDRs) are a characteristic feature of magma-rich margins, and represent the generation of large volumes of flood basalts at the point of continental breakup. A number of recent studies provide new insights into the emplacement and tilting of SDRs and conclude that the majority of SDRs are contained within new magmatic crust that has a close affinity to oceanic crust. However, the process by which these initial magmatic systems evolve into a fully established spreading centre remains poorly understood. Several characteristic features of magma-rich margins may be explained by the occurrence of rift-jumps during SDR emplacement, yet the cause and prevalence of such rift-jumps remain unknown. Here we constrain the 3D geometry of the continent–ocean transition in the Orange Basin, offshore South Africa. This allows us to test if, where and why such rift jumps occur. Our results demonstrate an order of along-strike segmentation previously unobserved in these settings. We demonstrate that the SDR belt is disrupted by the occurrence of a volcanic-stratigraphic package, defined as the Laterally Confined Volcanic Succession (LCVS), not previously identified on a rifted margin. We interpret this as a magmatic spreading centre that was abandoned by a subsequent rift-jump. Identification of LCVSs is important for two reasons. First, we argue that the LCVS formed via the same process as SDRs, and hence provides a unique example of SDR geometry prior to their separation onto conjugate plates. Second, as we can map out the 3D geometry of the LCVS and SDRs, we propose that rift-jumps during magma-rich margin formation may be fundamental to the establishment of a laterally continuous incipient spreading centre. © 2018 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/109609
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Basin Structure Group, School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, United Kingdom; Spectrum, Dukes Court, Woking, GU21 5BH, United Kingdom; Petroleum Agency South Africa, Bellville, Cape Town, 7530, South Africa
Recommended Citation:
Norcliffe J.R.,Paton D.A.,Mortimer E.J.,et al. Laterally Confined Volcanic Successions (LCVS); recording rift-jumps during the formation of magma-rich margins[J]. Earth and Planetary Science Letters,2018-01-01,504