Results 161 to 170 of about 3,825 (220)

North Atlantic Hydrography and the Mid-Atlantic Ridge

Geological Society of America Bulletin, 1949
This paper presents primarily the soundings obtained by the Research Vessel ATLANTIS during the summer field season of 1947. It also utilizes some of the data obtained by later expeditions of the ATLANTIS and by several other vessels. The ATLANTIS is equipped with a continuously recording fathometer with a range up to 4000 fathoms.
IVAN TOLSTOY, MAURICE EWING
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Sands of the Mid-Atlantic Ridge

Science, 1965
Sands collected at 24 locations along the crest of the Mid-Atlantic Ridge between 57°S and 38°N consist predominantly of olivine, diopsidic augite, hypersthene, enstatite, amphibole, quartz, plagioclase, and volcanic glass, suggesting an olivine tholeiitic source.
P J, Fox, B C, Heezen
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Nepheline Gabbro from the Mid-Atlantic Ridge

Nature, 1970
IN the course of a long range programme aimed at the study of the petrology of the Equatorial Mid-Atlantic Ridge, a series of dredgings were made by Miami's Institute of Marine Sciences on the walls of the Romanche trench. The Romanche is a major tectonic fracture which intersects the Ridge close to the Equator, and offsets its axis, perpendicular to ...
J, Honnorez, E, Bonatti
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Mid-Atlantic Ridge: Age and Spreading Rates

Science, 1968
Fission-track dating of basaltic glass from the Mid-Atlantic Ridge gives results which are consistent with the proposal of ocean-floor spreading. Solidification ages from ∼10,000 years to ∼300,000 years were measured. Correlation is also possible between the magnetic anomaly patterns over the Crest Mountains at 45°N and the geochronology of the ...
R L, Fleischer, J R, Viertl, P B, Price, F, Aumento   +3 more
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Tertiary Sediment from the Mid-Atlantic Ridge

Science, 1966
Lower Miocene microfossils occur in basaltic glass in two dredge hauls from the crestal area of the Mid-Atlantic Ridge near 30°N. From the ridge and adjoining abyssal hills 43 pre-Pleistocene cores were identified, including one Cretaceous and four Eocene.
T, Saito, M, Ewing, L H, Burckle
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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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