Surveyor Deep-Sea Channel extends for approximately 700 km
over the northern Alaskan Abyssal Plain. It originates near the base
of the continental slope opposite Dry Bay and Alsek Strath and terminates
in the Aleutian Trench south of Kodiak Island. East of Giacomini
Seamount, the axial gradient of the channel is in the order of 10 m/km
and its morphology is in agreement with prediction, assuming a depositional
equilibrium with channelized turbidity currents. West of
Giacomini Seamount, the axial gradient increases to values as high as
7.5 m/km, as the channel course turns toward the northwest and
plunges into the trench. Over this part of its length the measured
center channel relief and cross-sectional area of the channel increase,
contradicting prediction. The lower channel is found to be erosional
in nature, this effect being a response to downwarping of the northern
rim of the Pacific Plate into the Aleutian Trench.
The channel originated in early to middle Pliocene time coeval
with the initiation of pronounced tectonism and intense glaciation in
southeastern Alaska. At this time, the channel was located perhaps
200 km south of its present position with relation to the North
American Plate, and may have been linked with one of the fossil sea-channels
on the eastern Aleutian Abyssal Plain. Throughout its
history, the channel has not been linked with any consistent river
drainage system, its sediment source instead being the large system
of piedmont glaciers in southeastern Alaska.
The distribution of coarse sedimentary material over the
northern Gulf of Alaska strongly suggests that turbidity current activity
has not been confined to only those regions close to Surveyor
Deep-Sea Channel. / Graduation date: 1972
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/28430 |
| Date | 09 February 1972 |
| Creators | Ness, Gordon Everett |
| Contributors | Kulm, LaVerne D. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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