2-D and 3-D Magnetic Inversion Studies in the South Atlantic
Abstract
Our long range goals have been to achieve an understanding of crustal accretion along the Southern Mid-Atlantic Ridge. We address this problem with a combined analysis of bathymetry and sea surface magnetic data from two extensive Sea Beam surveys of the ridge between 25 deg-28 deg S and 30 deg-38 deg S. We are particularly interested in how crustal accretion may differ from accretion process in other areas spreading at faster and slower rates as spreading rates in South Atlantic area fall within a transitional range in which the axial rift valley begins to disappear. The great clarity of magnetic recording in the oceanic crust of the South Atlantic has enabled us to carry out a very thorough analysis of the magnetic data which, in turn, has provided us with powerful constraints on models of volcanic and tectonic crustal generation processes at slow spreading rates. Analysis of the magnetic data has included both 2-D and 3- D inversions which remove skewness and the effects of bathymetry. From 2-D analysis we have identified isochron boundaries and constructed spreading rate history models, thus defining the evolution of the ridge-axis discontinuities in the region. We have examined transition widths for evidence of any variation in the crustal accretion process with time or location. From 3-D analysis we have created maps of crustal magnetization that reveal zones of enhanced magnetization possibly related to fractionation process in the axial magma chamber.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA207068
Entities
People
- Ken C. Macdonald
- P. J. Fox
- S. M. Carbotte
- S. P. Miller
- S. Welch
Organizations
- University of California, Santa Barbara