气候变化领域集成服务门户(CCPortal): Deep structure of the Demerara Plateau: From a volcanic margin to a Transform Marginal Plateau

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DOI	10.1016/j.tecto.2020.228645
	Deep structure of the Demerara Plateau: From a volcanic margin to a Transform Marginal Plateau
	Museur T.; Graindorge D.; Klingelhoefer F.; Roest W.R.; Basile C.; Loncke L.; Sapin F.
发表日期	2021
ISSN	00401951
卷号	803
英文摘要	The Demerara Plateau (offshore Suriname and French Guiana) is located at the junction of the Jurassic Central Atlantic and the Cretaceous Equatorial Atlantic Oceans. The study of its crustal structure is fundamental to understanding its tectonic history, its relationship with the adjacent oceanic domains and to enlightening the formation of Transform Marginal Plateaus (TMPs). This study presents two wide-angle seismic velocity models from the MARGATS cruise seismic experiment, and adjacent composite seismic reflection lines. The plateau itself is characterized by a 30 km thick crust, subdivided into three layers, including a high velocity lower crust (HVLC). The velocities and velocity gradients do not fit values of typical continental crust but could fit with volcanic margin or Large Igneous Province (LIP) type crusts. We propose that the, possibly continental, lower crust is intruded by magmatic material and that the upper crustal layer is likely composed of extrusive volcanic rocks of the same magmatic origin, forming thick seaward dipping reflector sequences tilted to the west. This SDR complex was emplaced during hotspot related volcanic rifting preceding the Jurassic opening of the Central North Atlantic and forming the present-day western margin of the plateau. The internal limit of the SDR complex corresponds to the future limit of the eastern margin. The Demerara Plateau would therefore be an inherited Jurassic volcanic margin boarding the Central Atlantic. This margin was reworked during the Cretaceous at the eastern limit of the Jurassic SDR complex, creating the present-day northern transform margin and the eastern divergent margin along the Equatorial Atlantic. This study also highlights the major contribution of thermal anomalies such as hotspots and superposed tectonic phases in the history of TMPs, which share a great number of characteristics with Demerara. © 2020
英文关键词	Offshore oil well production; Seismic waves; Seismology; Structural geology; Tectonics; Velocity; Volcanoes; Continental crusts; Crustal structure; Large igneous provinces; Magmatic materials; Seismic reflections; Seismic velocity models; Thermal anomalies; Velocity gradients; Volcanic rocks; crustal structure; Jurassic; plateau; seismic reflection; seismic velocity; structural geology; tectonics; Atlantic Ocean; Atlantic Ocean (Central); Atlantic Ocean (Equatorial); French Guiana; Suriname
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/208038
作者单位	Ifremer, Géosciences Marines, Plouzané, F-29280, France; Univ Brest, Cnrs, Géosciences Océan, UMR6538, PLOUZANE, F-29280, France; ISTerre, UMR-CNRS 5275, Observatoire des Sciences de l'Univers de Grenoble, Université Joseph Fourier, Maison des Géosciences, 1381 rue de la Piscine, 38400 St. Martin d'Hères, France; University of Perpignan Via Domitia, Centre de Formation et de Recherche sur les Environnements Méditerranéens (CEFREM), UMR 5110, 52 Avenue Paul Alduy, Perpignan, 66100, France; Total SA, Centre Scientifique et Technique Jean Feger (CSTJF), Avenue Larribau, Pau, 64018, France
推荐引用方式 GB/T 7714	Museur T.,Graindorge D.,Klingelhoefer F.,et al. Deep structure of the Demerara Plateau: From a volcanic margin to a Transform Marginal Plateau[J],2021,803.
APA	Museur T..,Graindorge D..,Klingelhoefer F..,Roest W.R..,Basile C..,...&Sapin F..(2021).Deep structure of the Demerara Plateau: From a volcanic margin to a Transform Marginal Plateau.Tectonophysics,803.
MLA	Museur T.,et al."Deep structure of the Demerara Plateau: From a volcanic margin to a Transform Marginal Plateau".Tectonophysics 803(2021).