Constraints on mantle melting at mid-ocean ridges from global 238U- 230Th disequilibrium data
Article Abstract:
The relationship between mid-ocean-ridge basalts and axial depth of the ridge for 230Th/238U systematics results from mantle temperature variations rather than variations in mantle source composition. The disequilibrium data reveals that a large melt contribution from a garnet-bearing source is responsible for the excess 230Th present in samples from shallow ridges. The water content and chemical composition of the source affect the U-Th disequilibrium. The coupling between mantle temperature and heterogenicity poses a problem for the analysis of this disequilibrium.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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The influence of ridge migration on the magmatic segmentation of mid-ocean ridges
Article Abstract:
An attempt is made to show that magmatic segmentation of ridges with fast and intermediate spreading rates is directly related to the migration velocity of the spreading axis over the mantle. The Earth's mid-ocean ridges display systematic changes in depth and shape, which subdivide the ridges into discrete spreading segments bounded by transform faults and smaller non-transform offsets of the axis.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2004
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Spreading-rate dependence of the extent of mantle melting beneath ocean ridges
Article Abstract:
The extent of mantle melting beneath normal ocean ridges increases with increasing spreading rate. This was gleaned from a study of abyssal peridotites from the East Pacific Rise (EPR), which found that these are highly exhausted in basaltic major-element components. The depletion of these EPR abyssal peridotites indicates that these are residues of the highest extents of melting.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1997
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