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Submarine sand dunes and sedimentary environments in Oceanographer Canyon.

Journal of Sedimentary Petrology

By:
, , and
https://doi.org/10.1306/212F84DB-2B24-11D7-8648000102C1865D

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Abstract

Observations from research submersibles in the northern part of Oceanographer Canyon reveal the presence of an extensive field of large sand dunes on the canyon floor. The dunes are medium to coarse sand, are oriented across the axis, and the largest of them are as high as 3 m and have wavelengths up to 15 m. Their asymmetry, grain size, and height suggest that they are formed by axial currents flowing up- and downcanyon and that the largest dunes require flows of at least 70 cm/sec. Shelf sand, low in silt and clay content, is transported by currents down and along the canyon walls onto the canyon floor. As the sand enters the canyon, it is mixed with immobile gravel deposits on the canyon rim; lower on the walls, the sand is mixed with silt and clay burrowed by organisms from the semiconsolidated sandy silt that underlies the canyon walls and floor. Upon reaching the canyon floor, the sand is sculpted into bed forms by currents, and the fines are winnowed out and transported out of the canyon. At present, the shelf and canyon walls are being eroded by bottom currents and burrowing organisms, whereas the canyon floor is covered by mobile sand that moves both up and down the axis in this part of the canyon.

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Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Submarine sand dunes and sedimentary environments in Oceanographer Canyon.
Series title:
Journal of Sedimentary Petrology
DOI:
10.1306/212F84DB-2B24-11D7-8648000102C1865D
Volume:
54
Issue:
3
Year Published:
1984
Language:
English
Publisher:
American Geological Institute
Contributing office(s):
Woods Hole Coastal and Marine Science Center
Description:
12 p.
First page:
704
Last page:
715
Country:
United States