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Detailed Reference Information |
Murton, B.J., Tindle, A.G., Milton, J.A. and Sauter, D. (2005). Heterogeneity in southern Central Indian Ridge MORB: Implications for ridge–hot spot interaction. Geochemistry Geophysics Geosystems 6: doi: 10.1029/2004GC000798. issn: 1525-2027. |
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Between the Rodrigues Triple Junction and the Marie Celeste fracture zone, basalts from the Central Indian Ridge (CIR) exhibit an enrichment in incompatible elements that increases in intensity northward. In addition, H2O/TiO2, Al<8>, and Dy/Yb ratios increase, while Na<8> remains unchanged and Fe<8> decreases. Evolution of the enriched magma appears to be affected by elevated water contents, which lower the mantle solidus, thereby increasing the initial depth of melting, as well as delaying plagioclase crystallization. However, the enrichment affecting the northern samples is not a just function of hydrous mantle melting and crystallization. Instead of trending toward a small melt fraction from the mantle, as predicted by hydrous melting models, the CIR samples lie on a mixing line between N-MORB and a source component that closely resembles present-day R¿union hot spot lavas. Thus it appears that while hydrous melting and crystallization affect the CIR, the enriched and wet mantle originates from the R¿union hot spot, where it migrates eastward toward the CIR, against the direction of motion of the lithosphere. |
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Abstract |
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Keywords
Geochemistry, Composition of the oceanic crust, Geochemistry, Magma genesis and partial melting, Geochemistry, Mid-oceanic ridge processes (3614, 8416), Geochemistry, Magma chamber processes, Geochemistry, Mantle processes, Central Indian Ridge, hot spot–ridge interaction, MORB geochemistry |
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Journal
Geochemistry Geophysics Geosystems |
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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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