Passive Margins: Tectonics, Sedimentation and Magmatism
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This volume has evolved from papers written in memory of Professor David Roberts. They summarize the key findings of recent research on passive margins, from tectonics, bathymetry, stratigraphy and sedimentation, structural evolution and magmatism. Papers include analyses of the central and southern Atlantic margins of South America and Africa, papers on magmatism and extension in the NE Brazilian margin and on the Cote de Ivoire margin, rift architectures of the NW Red Sea margin, tectonics of the eastern Mediterranean margin, salt tectonics of passive margins of the Gulf of Mexico and Brazil, and papers on the NW Shelf margin of Australia. The volume provides readers with new insights into the complexities of passive margin systems that are in reality, not so passive.
Crustal structure of the central sector of the NE Brazilian equatorial margin
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Published:May 09, 2020
Abstract
The central equatorial Brazilian margin is divided into the Amazon and Barreirinhas divergent segments separated by the Pará-Maranhão transform segment. Analysis of regional 2D seismic lines allowed the definition of the crustal architecture of the margin. In the study area, the Barreirinhas segment has a proximal domain with a 30–35 km-thick continental crust, a 20–40 km-wide necked domain where the crust thins to 10 km, and an outboard domain with hyperextended continental crust. The Pará-Maranhão and Amazon segments consist of exhumation domains and their transition to ocean crust. Their structural styles indicate that this is a magma-poor passive margin...