Mantle wehrlite from Hess Deep as a crystal cumulate from an ultra-depleted primary melt in East Pacific Rise
نویسندگان
چکیده
منابع مشابه
Continuous mantle melt supply beneath an overlapping spreading center on the East Pacific Rise.
Tomographic images of upper mantle velocity structure beneath an overlapping spreading center (OSC) on the East Pacific Rise indicate that this ridge axis discontinuity is underlain by a continuous region of low P-wave velocities. The anomalous structure can be explained by an approximately 16-kilometer-wide region of high temperatures and melt fractions of a few percent by volume. Our results ...
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Relative travel time delays of teleseismic P and S waves, recorded during the Mantle Electromagnetic and Tomography (MELT) Experiment, have been inverted tomographically for upper-mantle structure beneath the southern East Pacific Rise. A broad zone of low seismic velocities extends beneath the rise to depths of about 200 kilometers and is centered to the west of the spreading center. The magni...
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Earth's tectonic plates are generally considered to be driven largely by negative buoyancy associated with subduction of oceanic lithosphere. In this context, mid-ocean ridges (MORs) are passive plate boundaries whose divergence accommodates flow driven by subduction of oceanic slabs at trenches. We show that over the past 80 million years (My), the East Pacific Rise (EPR), Earth's dominant MOR...
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We report 230Th-238U disequilibrium data on mid-ocean ridge basalts recovered 5 to 40 kilometers off the ridge axis near 9 degrees 30'N of the East Pacific Rise. These data indicate near-symmetrical eruptions of normal mid-ocean ridge basalts (NMORBs) and incompatible element-enriched mid-ocean ridge basalts (EMORBs) as far as 20 kilometers off axis. Our results suggest large-scale subsurface l...
متن کاملWhole mantle shear structure beneath the East Pacific Rise
[1] We model broadband seismograms containing triplicated S, S, and S along with ScS to produce a pure path one-dimensional model extending from the crust to the core-mantle boundary beneath the East Pacific Rise. We simultaneously model all body wave shapes and amplitudes, thereby eliminating depth-velocity ambiguities. The data consist of western North American broadband recordings of East Pa...
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ژورنال
عنوان ژورنال: Geophysical Research Letters
سال: 2007
ISSN: 0094-8276
DOI: 10.1029/2006gl029198