Papers on Geomagnetism and Paleomagnetism Marine Geology and Geophysics
The Aegir Ridge: Structure of an extinct spreading axis
Article first published online: 20 SEP 2012
Copyright 1992 by the American Geophysical Union.
Journal of Geophysical Research: Solid Earth (1978–2012)
Volume 97, Issue B6, pages 9203–9218, 10 June 1992
How to Cite
1992), The Aegir Ridge: Structure of an extinct spreading axis, J. Geophys. Res., 97(B6), 9203–9218, doi:10.1029/91JB03096., , , and (
- Issue published online: 20 SEP 2012
- Article first published online: 20 SEP 2012
- Manuscript Accepted: 9 AUG 1991
- Manuscript Received: 2 JAN 1991
In 1988 a reflection seismic survey was carried out by the Alfred-Wegener-Institute for Polar and Marine Research to study structure and development of the Aegir Ridge, an extinct spreading axis in the Norway Basin. A number of volcanolike structures were detected in the central ridge. The emerging lava flows dip away from their source in ridge strike. Perpendicular to ridge strike, we observed lava flows dipping towards the ridge center. This pattern might represent a more general flow pattern at mid-ocean ridges. After spreading ceased, sedimentation resulted in the deposition of 800 ms two-way time (TWT) to 1300 ms TWT (about 900–1400 m) sediments in the central ridge. Distribution of the sediments indicate subsidence of the central ridge probably due to cooling after termination of spreading. This subsidence started no later than late Oligocene or early Miocene. We detected an area where migration of a fluid phase led to obstruction of the sedimentary layering and the formation of mounds and faults at the ocean bottom. Several sources for the fluid phase are discussed.