Crustal Thickness on the Mid-Atlantic Ridge - Bulls-Eye Gravity-Anomalies and Focused Accretion

Publication Type  Journal Article
Year of Publication  1993
Authors  Tolstoy, M.; Harding, A. J.; Orcutt, J. A.
Journal Title  Science
Volume  262
Issue  5134
Pages  726-729
Journal Date  Oct 29
ISBN Number  0036-8075
Accession Number  ISI:A1993MD95200037
Key Words  spreading rate dependence; fracture-zone; mark area; axis discontinuities; seismic refraction; magma chamber; ocean ridge; beneath; 23-degrees-n; profiles

Spreading segments of the Mid-Atlantic Ridge show negative bull's-eye anomalies in the mantle Bouguer gravity field. Seismic refraction results from 33-degrees-S indicate that these anomalies can be accounted for by variations in crustal thickness along a segment. The crust is thicker in the center and thinner at the end of the spreading segment, and these changes are attributable to variations in the thickness of layer 3. The results show that accretion is focused at a slow-spreading ridge, that axial valley depth reflects the thickness of the underlying crust, and that along-axis density variations should be considered in the interpretation of gravity data.


Md952Times Cited:124Cited References Count:31

URL  <Go to ISI>://A1993MD95200037