Geophysics of Atlantic North America

摘要: On the basis of geophysical data, East Coast margin can be divided into three structural provinces which are largely unrelated to shelf-sloperise morphological provinces. The eastern province extends from abyssal plains magnetic slope anomaly. central centers on outer shelf. Its seaward boundary is anomaly, in northern area lies well out over continental rise. Model calculations consistent with view that anomaly marks edge oceanic crust. western ill-defined but somewhere beneath inner characterized by great mobility. Deeply subsided fault-block basins this belt filled huge thicknesses sediments, basal sequences at least as old Late Triassic-Early Jurassic. Roughly lower half section these high seismic velocity and has previously been interpreted basement. province, included much Appalachian crystalline belt, a zone relatively minor vertical mobility thin sediments. subsidence seen result regional rise aesthenosphere prior rifting, partially followed lithospheric grain, was concentrated province.