thumbnail

Sea-floor drainage features of Cascadia Basin and the adjacent continental slope, northeast Pacific Ocean

Marine Geology

By:
, , and

Links

  • The Publications Warehouse does not have links to digital versions of this publication at this time
  • Download citation as: RIS

Abstract

Sea-floor drainage features of Cascadia Basin and the adjacent continental slope include canyons, primary fan valleys, deep-sea valleys, and remnant valley segments. Long-range sidescan sonographs and associated seismic-reflection profiles indicate that the canyons may originate along a mid-slope escarpment and grow upslope by mass wasting and downslope by valley erosion or aggradation. Most canyons are partly filled with sediment, and Quillayute Canyon is almost completely filled. Under normal growth conditions, the larger canyons connect with primary fan valleys or deep-sea valleys in Cascadia Basin, but development of accretionary ridges blocks or re-routes most canyons, forcing abandonment of the associated valleys in the basin. Astoria Fan has a primary fan valley that connects with Astoria Canyon at the fan apex. The fan valley is bordered by parallel levees on the upper fan but becomes obscure on the lower fan, where a few valley segments appear on the sonographs. Apparently, Nitinat Fan does not presently have a primary fan valley; none of the numerous valleys on the fan connect with a canyon. The Willapa-Cascadia-Vancouver-Juan de Fuca deep-sea valley system bypasses the submarine fans and includes deeply incised valleys to broad shallow swales, as well as within-valley terraces and hanging-valley confluences. ?? 1989.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Sea-floor drainage features of Cascadia Basin and the adjacent continental slope, northeast Pacific Ocean
Series title:
Marine Geology
Volume
87
Issue:
2-4
Year Published:
1989
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Marine Geology
First page:
249
Last page:
272