Three-dimensional shallow crustal emplacement at 9,03'N overlapping spreading center on the East Pacific Rise: correlations between magnetization and tomographic images


Bazin, S. and Sinha, M.C. (2001) Three-dimensional shallow crustal emplacement at 9,03'N overlapping spreading center on the East Pacific Rise: correlations between magnetization and tomographic images. Journal of Geophysical Research B (Solid Earth), 106, (B8), 16101-16117.

Download

Full text not available from this repository.

Description/Abstract

We report a three-dimensional (3-D) seismic reflection and tomographic survey conducted at the 9°03'N overlapping spreading center (OSC) on the East Pacific Rise to understand crustal accretion at this feature. Inversions of travel time data from 19 ocean bottom hydrophones provide a 3-D image of the shallow velocity structure beneath the nontransform offset and associated discordance zone. Seismic analysis indicates that layer 2A thickness varies between 100 and 900 m and averages 430 m throughout the study area. The heterogeneous upper crustal structure at the OSC region contrasts with the simpler symmetric structure flanking the midsegments of the East Pacific Rise. The crust affected by the OSC migration carries evidence for the complex accretion at the axial discontinuity where the overlap basin may act as a lava pond. An area of thick layer 2A covers the southern half of the overlap basin and the propagating ridge tip and shows good correlation with a high magnetization region. Comparison of the magnetic field anomaly derived from the seismic structure model with the observed sea surface magnetic anomaly suggests that a significant portion of the high magnetization can be related to magnetic source thickness variation rather than solely to the geochemistry of the volcanic rocks.

Item Type: Article
Related URLs:
Keywords: SEISMIC REFLECTION, CRUSTAL ACCRETION, CRUSTAL STRUCTURE, SEISMIC MODELING, GEOLOGY
Subjects: Q Science > QE Geology
G Geography. Anthropology. Recreation > GC Oceanography
Divisions: University Structure - Pre August 2011 > School of Ocean & Earth Science (SOC/SOES)
ePrint ID: 8025
Date Deposited: 08 Sep 2004
Last Modified: 27 Mar 2014 18:00
URI: http://eprints.soton.ac.uk/id/eprint/8025

Actions (login required)

View Item View Item