SEDIMENTS AND SEDIMENTATION AT THE NE FAEROE CONTINENTAL-MARGIN - CONTOURITES AND LARGE-SCALE SLIDING

Citation
Tce. Vanweering et al., SEDIMENTS AND SEDIMENTATION AT THE NE FAEROE CONTINENTAL-MARGIN - CONTOURITES AND LARGE-SCALE SLIDING, Marine geology, 152(1-3), 1998, pp. 159-176
Citations number
29
Categorie Soggetti
Oceanografhy,"Geosciences, Interdisciplinary
Journal title
ISSN journal
00253227
Volume
152
Issue
1-3
Year of publication
1998
Pages
159 - 176
Database
ISI
SICI code
0025-3227(1998)152:1-3<159:SASATN>2.0.ZU;2-F
Abstract
High-resolution seismic profiles of the NE Faeroe continental margin s how a wedge-shaped sedimentary sequence of up to 2 km thickness on top of lower Tertiary basaltic basement. The sedimentary section can be d ivided into four major seismic sequences separated by unconformities. The uppermost upper slope deposit is interpreted as a contourite which formed later than the Mid-Miocene by the southerly flow of bottom wat er along the margin of the SW Norwegian Sea, which is subsequently def lected to the east by the NE Faeroe continental margin and Fugloy Ridg e. A scoured channel about 85-90 m deep at about 1000 m water depth as sociated with the contourite partially follows and modifies a preexist ing slump scar. Large-scale slumping and sliding of the middle and low er continental slope below 1500 m water depth have affected sediments of presumably Miocene, Pliocene and Quaternary age. A TOBI deep-tow si de-scan sonar mosaic composed of ten lines recorded in 1995 semi-paral lel to the slope, shows that mass flow deposits are partially covered by recent contourite sediments on the middle slope. The slump complex at the middle/lower continental slope is younger and has a steep, 250- 300 m, irregular, deep main scarp and very large, sometimes rotated bl ocks near the main scarp. Ar the base of the slide, numerous 10-15 km long, narrow tracks with individual blocks at the end are found. Sever al types of debris flows have been mapped, some with a longitudinal fl ow fabric. (C) 1998 Elsevier Science B.V. All rights reserved.