Crustal thickness of V-shaped ridges south of the Azores: Interaction of the Mid-Atlantic Ridge (36°-39°N) and the Azores hot spot
V‐shaped ridges propagating along the Mid‐Atlantic Ridge axis south of the Azores and Iceland hot spots indicate that ridge‐hot spot interactions produce temporal and spatial variations in melt supply to the ridge axis. Estimates of relative crustal thickness variations associated with the ridges so...
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Veröffentlicht in: | Journal of Geophysical Research: Solid Earth 2001-10, Vol.106 (B10), p.21719-21735 |
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Sprache: | eng |
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Zusammenfassung: | V‐shaped ridges propagating along the Mid‐Atlantic Ridge axis south of the Azores and Iceland hot spots indicate that ridge‐hot spot interactions produce temporal and spatial variations in melt supply to the ridge axis. Estimates of relative crustal thickness variations associated with the ridges south of the Azores hot spots, based on gravity and bathymetry data collected during the SudAçores cruise (1998), provide constraints on the rate of propagation of these melt anomalies and on the variations in melt production along the axis and in time. The maximum apparent crustal thickness along the Azores V ridge is ∼14 km near the Azores, decreasing to normal crustal thickness of ∼6 km toward the south. This crustal thickness variation may be explained by enhanced melt production associated with the propagation of a mantle temperature anomaly that initiated ∼10 Myr ago at the Azores hot spot. The temperature anomaly decreased as it propagated southward, reaching ambient mantle temperatures at the present time at its predicted location under the axis. The excess melt was emplaced on axis forming discrete, shallow ( |
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ISSN: | 0148-0227 2169-9313 2156-2202 2169-9356 |
DOI: | 10.1029/2001JB000224 |