Marine Geology Program, Polar Continental Shelf Project

A geological reconnaissance has been made of the continental slope of western Europe between the Faeroe Isles and Lisbon by means of a 60 kj reflexion profiler, supplemented by Boomer profiles and extensive Asdic (side-looking sonar) coverage of the continental shelf. A tentative interpretation of these profiles has been made by references to available rock samples and seismic refraction data. The first-formed continental slope deposits of the north-east Atlantic appear to be Cretaceous in age. Massive erosion (particularly of the continental shelf) preceded the Tertiary phase of downwarping which allowed upbuilding and outbuilding of the continental margin and was followed by a latest-Tertiary and Quaternary phase of important faulting, canyon erosion, slumping and deposition. This episodic evolution of the European continental margin is thought to indicate two phases of continental drift. In contrast to the ground west of the British Isles and France the steep and narrow northern and western continental margins of Iberia show only a little upbuilding and only local outbuilding. The work was done from aboard R.R.S. Discovery II or R.R.S. Discovery (with the exception of a Sparker profile obtained by H.M.T.S. Alert ), the powerful profiler being used in 1965, the Asdic on many cruises between 1958 and 1967.

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Marine Geology, South Texas Outer Continental Shelf: A Processes Approach

10.1109/oceans.1976.1154203 ◽

1976 ◽

Author(s):

H. Berryhill

Keyword(s):

Continental Shelf ◽

South Texas ◽

Marine Geology ◽

Outer Continental Shelf

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The deeper structure of the ocean floor

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1962.0028 ◽

1962 ◽

Vol 265 (1322) ◽

pp. 386-395 ◽

Cited By ~ 1

Keyword(s):

Continental Shelf ◽

Ocean Floor ◽

Marine Geology ◽

Piston Corer ◽

Sea Floor ◽

Parallel Development ◽

Surface Ship ◽

Laboratory Facilities

For 25 years those interested in the geology of the oceans have stressed our ignorance, and the importance of an understanding of marine geology. Perhaps the time has come to admit that we now do know a great deal and can see where the uncertainties and problems for the next few years probably lie. Many of the questions that were asked in the 1930’s (Field 1938; Bullard 1939, 1940) have been answered. We now know in some detail what lies beneath the continental shelf, we know the thickness of the sediments in the deep oceans and we can classify the major forms of oceanic topography. The gear used in the study of the sea floor has also greatly improved. Kuhlenberg’s piston corer enables more-or-less undisturbed cores to be collected, whose length is limited only by the length of the coring tube that can be handled; Graf and La Coste have devised gravimeters that can be used on a surface ship and there are several types of magnetometers that can be towed behind a ship. Along with the development of instruments for use at sea there has been a parallel development of laboratory facilities on shore for the chemical, physical and palaeontological study of the specimens obtained.

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Biology of an active methane seep on the Oregon continental shelf

Marine Ecology Progress Series ◽

10.3354/meps095287 ◽

1993 ◽

Vol 95 ◽

pp. 287-294

Author(s):

AR Juhl ◽

GL Taghon

Keyword(s):

Continental Shelf ◽

Methane Seep

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Isotopic characterization of lifetime movement by two demersal fishes from the northeastern Gulf of Mexico

Marine Ecology Progress Series ◽

10.3354/meps13525 ◽

2021 ◽

Vol 657 ◽

pp. 161-172

Author(s):

JL Vecchio ◽

JL Ostroff ◽

EB Peebles

Keyword(s):

Gulf Of Mexico ◽

Continental Shelf ◽

Life Histories ◽

Linear Mixed Model ◽

Trophic Position ◽

Eye Lens ◽

Outer Continental Shelf ◽

Red Grouper ◽

Lens Diameter ◽

Isotopic Characterization

An understanding of lifetime trophic changes and ontogenetic habitat shifts is essential to the preservation of marine fish species. We used carbon and nitrogen stable isotope values (δ13C and δ15N) recorded within the laminar structure of fish eye lenses, reflecting both diet and location over time, to compare the lifetime trends of 2 demersal mesopredators. Tilefish Lopholatilus chamaeleonticeps inhabit burrows on the outer continental shelf, which results in exceptional site fidelity. Red grouper Epinephelus morio are spawned on the middle to outer continental shelf, move to the inner shelf for the juvenile period, and return offshore upon sexual maturity. Both species inhabit the eastern Gulf of Mexico, a region with a distinctive offshore-inshore gradient in background δ13C values. Within individual tilefish (n = 36), sequences of δ13C values and δ15N values had strong, positive correlations with eye-lens diameter, and strong correlations between the 2 isotopes (mean Spearman r = 0.86), reflecting an increase in trophic position with growth and little lifetime movement. In red grouper (n = 30), δ15N values positively correlated with eye-lens diameter, but correlations between δ15N and δ13C were weak (mean Spearman r = 0.29), suggesting cross-shelf ontogenetic movements. Linear mixed model results indicated strong relationships between δ15N and δ13C values in tilefish eye lenses but no convergence in the red grouper model. Collectively, these results are consistent with previously established differences in the life histories of the 2 species, demonstrating the potential utility of eye-lens isotope records, particularly for investigating the life histories of lesser-known species.

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