Sediment transport and fan deposition in the Gulf of Alaska: Effects of transform motion on deep sea sedimentation
- Geological Survey, Palo Alto, CA (USA)
- Univ. of College of Wales, Aberystwyth (Wales)
GLORIA side-scan sonar images and two channel seismic profiles recently collected in the Gulf of Alaska reveal a major site of late Miocene to Recent terrigenous sediment accumulation on the oceanic plate adjacent to the Fairweather-Queen Charlotte transform and the Yakutat Terrane. Sediment moving across this margin has formed several large channel dominated fan systems that blanket the entire gulf and spill westward onto the Tufts Abyssal Plain. The Surveyor Fan, fed by the glaciers of the Yakutat Terrane and insulated from transform sediment source offset by the Terrane, has maintained a single channel course over the entire life of the fan. The Chirikov and Baranof fans receive their sediment supply from glaciofluvial point sources along the SE Alaska margin, separated from the fans by an active transform. The fans show a southward younging of channel ages consistent with the sense of plate motion. Early (late Miocene) deposition within the gulf was limited to the structural basin between the continental margin and the Kodiak-Bowie seamount chain. The geometry of these early depositional systems is poorly known, but available data suggest their channels were oriented NW-SE. Subsequent establishment of a depositional slope between the margin and the seamount chain, coupled with the filling of the basin, led to a reorganization into SW-NE channel systems. The fan bodies of the Gulf of Alaska are members of a distinct class of fans that are characterized by long distributary channels which persist to near the fan limits. This type of fan morphology is most often attributed to a predominantly fine-grained sediment supply. This is difficult to reconcile with the obvious proximal glacial source for much of the sediment supplied to these fans.
- OSTI ID:
- 6163800
- Report Number(s):
- CONF-900702-; CODEN: AABUD
- Journal Information:
- AAPG Bulletin (American Association of Petroleum Geologists); (USA), Vol. 74:6; Conference: 5. Circum-Pacific energy and mineral resources conference, Honolulu, HI (USA), 29 Jul - 3 Aug 1990; ISSN 0149-1423
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
58 GEOSCIENCES
ALASKA
SEISMIC SURVEYS
DEPOSITION
OFFSHORE SITES
QUATERNARY PERIOD
SEDIMENTARY BASINS
SEDIMENTATION
TERTIARY PERIOD
CENOZOIC ERA
FEDERAL REGION X
GEOLOGIC AGES
GEOLOGIC STRUCTURES
GEOPHYSICAL SURVEYS
NORTH AMERICA
SURVEYS
USA
020200* - Petroleum- Reserves
Geology
& Exploration
580000 - Geosciences