L. Morgan, W. Dowdall, 1983. "The Atlantic Continental Margin", Seismic Expression of Structural Styles: A Picture and Work Atlas. Volume 1–The Layered Earth, Volume 2–Tectonics Of Extensional Provinces, & Volume 3–Tectonics Of Compressional Provinces, A. W. Bally
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The Atlantic continental margin is often referred to as a passive margin because today it is located near the center of the North American plate and displays little seismic or volcanic activity. It is also considered to be a divergent margin because the lithospheric plates moved away or diverged from the mid-Atlantic ridge, which developed at the boundaries between the North American and the European and African plates.
The Atlantic continental margin developed during an extensional phase of crustal deformation that began in the latter part of the Triassic. Its evolution took place in three main stages (Bally, 1981): (1) a rifting phase which involved stretching of the lithosphere and thermal uplift of the mantle (this phase was characterized by complex horst and graben tectonics); (2) the onset of drifting which involved the separation of continental lithosphere (oceanic crust was emplaced for the first time and accretion by sea-floor spreading across mid-ocean ridges began in the gaps between attenuated continental blocks); and (3) a main drifting phase which was dominated by massive subsidence with rates of subsidence that decreased exponentially from the date of the onset of drifting.