Improved images of the internal structure of Early Cretaceous North Atlantic crust reveal both probable detachment faults and more steeply dipping normal faults. The detachment faults occur as subhorizontal structures passing ∼ 1.5 km beneath fault blocks without offset; several steeper block-bounding faults appear to detach onto these structures. However, the detachments are bounded to the west (ridgeward) by presumably younger, more steeply west-dipping normal faults. In one possible interpretation, the detachment and the steep faults belong to the same “rolling-hinge” extension system. An intriguing alternative is that a phase of detachment faulting, perhaps related to increased magmatic activity, was succeeded by localized amagmatic extension along steeper and more deeply penetrating faults.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

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