Journal ArticleDOI
The Vema fracture zone and the tectonics of transverse shear zones in oceanic crustal plates
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In this paper, the authors explain the high heat flow and the shape of the Vema fracture as the results of secondary sea-floor spreading produced by a reorientation of the direction of sea floor spreading from W10°N to west-east.Abstract:
At 11°N latitude, the Mid-Atlantic ridge is offset 300 km by the Vema fracture zone. Between the ridge offset, the fracture consists of an elongate, parallelogram-shaped trough bordered on the north and south by narrow, high walls. The W-E trending valley floor is segmented by basement ridges and troughs which trend W10°N and are deeply buried by sediment. Uniform high heat flow characterizes the valley area. Seismically inactive valleys south of the Vema fracture, also trending W10°N, are interpreted as relict fracture zones. We explain the high heat flow and the shape of the Vema fracture as the results of secondary sea-floor spreading produced by a reorientation of the direction of sea-floor spreading from W10°N to west-east. This reorientation probably began approximately 10 million years ago. Rapid filling of the fracture valley by turbidites from the Demerara Abyssal plain took place during the last million years.read more
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Abyssal peridotites, very slow spreading ridges and ocean ridge magmatism
TL;DR: In this paper, it was shown that the seafloor peridotites of the SW Indian and American-Antarctic Ridges contain up to 30% trapped melt.
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A tectonic model for ridge-transform-ridge plate boundaries: implications for the structure of oceanic lithosphere
Paul J. Fox,David G. Gallo +1 more
TL;DR: In this article, the first-order geologic and morphologic relationships at, along and proximal to ridge-transform-ridge plate boundaries are used to construct an empirical and speculative tectonic model.
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Open system melting and temporal and spatial variation of peridotite and basalt at the Atlantis II Fracture Zone
TL;DR: In situ ion microprobe analysis of trace and rare earth elements in discrete diopsides in abyssal peridotites from nine transform dredge hauls from the Atlantis II Fracture Zone (All FZ) shows that these samples have a wide range of trace element contents close to the total range found for the entire Southwest Indian Ridge as discussed by the authors.
Journal ArticleDOI
Hydrothermal serpentinization of peridotite within the oceanic crust: Experimental investigations of mineralogy and major element chemistry
TL;DR: In this paper, the authors investigated the interaction of equigranular peridotites with seawater and seawater derived solutions at 200°C and 300°C, 500 bars and found that the reaction rates of olivine to enstatite to be approximately 1.5:5:1 (moles per unit time per unit surface area).
Journal ArticleDOI
Tectonics of ridge-transform intersections at the Kane fracture zone
TL;DR: The Kane Transform offsets spreading-center segments of the Mid-Atlantic Ridge by about 150 km at 24° N latitude in terms of its first-order morphological, geological, and geophysical characteristics.
References
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Journal ArticleDOI
Seismology and the new global tectonics
TL;DR: In this article, a comprehensive study of the observations of seismology provides widely based strong support for the new global tectonics which is founded on the hypotheses of continental drift, sea-floor spreading, transform faults and underthrusting of the lithosphere at island arcs.
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Sea-floor spreading and continental drift
TL;DR: In this article, a geometrical model of the surface of the earth is obtained in terms of rigid blocks in relative motion with respect to each other, and a simplified but complete and consistent picture of the global pattern of surface motion is given on the basis of data on sea-floor spreading.
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A New Class of Faults and their Bearing on Continental Drift
TL;DR: In this article, the authors proposed the notion of dextral transform faults, which can be seen as a pair of half-shears joined end-to-end, which is the case of the San Andreas Transform Fault.