Fracture-zone distribution in the North Atlantic Ocean varies from closely spaced (about 50 km) to widely spaced (300 km) between the equator and the Azores hotspot across the Mid-Atlantic Ridge. North of the Azores hotspot, seamount chains predominate in place of fracture valleys. The fracture-zone trends are taken from a data base with the ability to show fracture valleys of several kilometres width. Whereas the past 200 m.y. of kinematic history in the Atlantic may be recorded in the magnetic lineations, these lineations are not adequate to show actual spreading flow lines and, in fact, cloud the actual bathymetry of fracture-valley orientation.

First Page Preview

First page PDF preview
You do not currently have access to this article.