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Detailed Reference Information |
Douglass, J., Schilling, J., Kingsley, R.H. and Small, C. (1995). Influence of the discovery and Shona mantle plumes on the southern Mid-Atlantic Ridge: Rare earth evidence. Geophysical Research Letters 22: doi: 10.1029/95GL02665. issn: 0094-8276. |
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Chondrite normalized (La/Sm)n ratio variations from 66 basalt glasses dredged along the Mid-Atlantic Ridge (MAR) from 40--54.5 ¿S reveal two distinct geochemical anomaly highs coupled with gravity and bathymetric highs and crest-like rather than rifted ridge-axis morphology. The Discovery anomaly (45--49 ¿S), located opposite the Discovery hotspot track, is irregular and shows large local variation. The Shona anomaly (50--52.5 ¿S) is smoother and shows less local variation. These results suggest that the influential Shona mantle plume may be located on or very close to the ridge. In contrast, the dispersal of the Discovery plume, located well off the ridge, is affected in a complex manner by the Agulhas fracture zone and the asthenospheric flow field associated with the spreading MAR. ¿ American Geophysical Union 1995 |
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Abstract |
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Keywords
Marine Geology and Geophysics, Midocean ridge processes, Geodesy and Gravity, Regional and global gravity anomalies and Earth structure, Mineralogy and Petrology, Minor and trace element composition |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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