The structure and subsidence of Rockall Trough from two-ship seismic experiments

Journal Article · Sat Nov 10 04:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JB095iB12p19821· OSTI ID:5319792

Joppen, M; White, R S ^[1]

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1. Cambridge Univ. (England)

Coincident multichannel seismic reflection and refraction profiles acquired northwest of Britain during a two-ship seismic experiment in the southern Rockall Trough provide evidence for a thin (6 km) syn-rift crust below Rockall Trough. The variation of seismic velocity with depth is consistent with either oceanic crust similar to that found in other parts of the North Atlantic or with thinned continental crust heavily intruded by syn-rift igneous rocks. The syn-rift crust beneath Rockall Trough is now buried by nearly 5 km of sediments that are intruded by Tertiary volcanics varying in extent from isolated sills to a large sill complex extending 100 km laterally. The basement imaged on seismic profiles exhibits a band of subhorizontal reflectors that extend laterally over distances of up to 40 km which they interpret as sediments intercalated with submarine lava flow generated during the opening of the Trough. Estimates of stretching from crustal thinning and from subsidence indicate that Rockall Trough has undergone extensive rifting ({beta} > 6). Upwelling asthenosphere beneath the thinned lithosphere generated at least 1-3 km thickness of melt as it decompressed. The molten rock rose upward from the mantle until it was in part extruded as lava flows and in part intruded into the crust.

• OSTI ID: 5319792
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:B12; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
ATLANTIC OCEAN
BASEMENT ROCK
CENOZOIC ERA
CONTINENTAL CRUST
DEPTH
DIMENSIONS
EARTH CRUST
EXTRUSION
FABRICATION
GEOLOGIC AGES
GEOLOGIC FORMATIONS
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
IGNEOUS ROCKS
LAVA
MATERIALS WORKING
OCEANIC CRUST
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
REFLECTIVITY
REFRACTIVITY
RIFT ZONES
ROCKS
SEAS
SEDIMENTS
SEISMIC SURVEYS
SHIPS
SURFACE PROPERTIES
SURFACE WATERS
SURVEYS
TERTIARY PERIOD
THICKNESS
VOLCANOES
WAVE PROPAGATION