Results 201 to 210 of about 113,713 (252)

Nonspreading Crustal Blocks at the Mid-Atlantic Ridge

Science, 1971
Transverse ridges consisting of protrusions into crustal fractures of ultramafic bodies derived from the upper mantle exist at the intersection of the Mid-Atlantic Ridge with equatorial fracture zones. Shallow-water limestones containing detrital grains of quartz, microcline, and orthoclase 1 millimeter in diameter were found on the summit of one such ...
E, Bonatti, J, Honnorez
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Composition of Basalts from the Mid-Atlantic Ridge

Science, 1964
Studies of volcanic rocks in dredge hauls from the submerged parts of the Mid-Atlantic Ridge suggest that it consists largely of tholeiitic basalt with low values of K, Ti, and P. In contrast, the volcanic islands which form the elevated caps on the Ridge are built of alkali basalt with high values of Ti, Fe 3+ , P,
A E, Engel, C G, Engel
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Seafloor insonification near the Mid-Atlantic Ridge

The Journal of the Acoustical Society of America, 1994
As part of the Acoustical Reverberation Special Research Program (ARSRP), several at-sea experiments were performed near the Mid-Atlantic Ridge to understand low grazing angle backscattering from the ocean seafloor. Although the bathymetry for this region is known, the seafloor has not been classified into acoustically relevant types.
Vincent H. Lupien, J. Robert Fricke
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Acoustic color of the Mid-Atlantic Ridge

The Journal of the Acoustical Society of America, 1994
Narrow-band waveforms in the frequency range 200–300 Hz were transmitted from a vertical source array during the Main Acoustics Experiment (SRP) of July 1993. The resulting backscatter from the ocean bottom was received on a horizontal array. Two-way travel times are computed using a ray trace that includes bottom and surface interacting paths ...
Nicholas C. Makris, Richard Menis, Lilimar Avelino   +2 more
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Structure of the Mid‐Atlantic Ridge

Eos, Transactions American Geophysical Union, 1949
Atlantis Cruise 150, sponsored by the National Geographic Society, Columbia University, and the Woods Hole Oceanographic Institution, was a two month trip to Bermuda, the Azores the Mid‐Atlantic Ridge in the summer of 1947. A continuous record of depth beneath the ship along the track gave significant topographic information and provided a valuable ...
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Microearthquake Survey of the Mid-Atlantic Ridge

Nature, 1972
THE association of earthquakes with the axis of the Mid-Atlantic ridge is well known1–4, and it has been realized that where a median valley existed, the pattern of epicentres stratified it5,6. The first motions and distribution of earthquakes along fracture zones confirm the hypothesis of transform faults and hence give support to ideas of sea floor ...
T. J. G. FRANCIS, I. T. PORTER
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Rocks of the Mid-Atlantic Ridge

The Journal of Geology, 1949
A remarkable achievement by the Atlantis expedition (1947) of the Woods Hole Oceanographic Institution, under the leadership of Professor Maurice Ewing, was the recovery of several hundred pounds of boulders from depths approaching 2,500 fathoms over the Mid-Atlantic Ridge.
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Mid-Atlantic Ridge near 43°N latitude

Journal of Geophysical Research, 1969
The results of a reconnaissance bathymetric and magnetic survey of the mid-Atlantic ridge between 42° and 45°N latitude show a symmetrical north-south magnetic pattern parallel to the axis over the two southernmost of six profiles across the ridge. The southern profiles are also characterized by a well developed central rift valley.
J. D. Phillips, G. Thompson, R. P. Von Herzen, V. T. Bowen   +3 more
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Magnetic spherules from the Mid-Atlantic Ridge

Geology, 1975
Scanning electron microscope investigations of magnetic spherules similar to those thought to be the ablation products of meteorites reveal microstructures that may be significant in determining the origin of the spherules.
F. Aumento, W. S. Mitchell
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Petrologic models for the Mid-Atlantic Ridge

Deep Sea Research and Oceanographic Abstracts, 1970
Abstract Serpentinites and metabasites (metabasalts and metagabbros) occur in association with unmetamorphosed basalts in transverse fracture zones cutting deeply across the Mid-Atlantic Ridge. The serpentinites appear to have been formed by hydration of upper mantle peridotites.
Akiho Miyashiro, Fumiko Shido, Maurice Ewing   +2 more
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