Reece, Robert S. et al. (2011): Tectonic and climatic influence on the evolution of the Surveyor Fan and Channel system, Gulf of Alaska

Leg/Site/Hole:
DSDP 18
DSDP 18 178
Identifier:
2011-079208
georefid

10.1130/GES00654.1
doi

Creator:
Reece, Robert S.
University of Texas at Austin, Jackson School of Geosciences, Austin, TX, United States
author

Gulick, Sean P. S.
Texas A&M University, United States
author

Horton, Brian K.
author

Christeson, Gail L.
author

Worthington, Lindsay L.
author

Identification:
Tectonic and climatic influence on the evolution of the Surveyor Fan and Channel system, Gulf of Alaska
2011
Geosphere
Geological Society of America, Boulder, CO, United States
7
4
830-844
Present-day seafloor morphology and sediment distribution in the deep-water Surveyor Fan, Gulf of Alaska, is dominated by the >700-km-long Surveyor Channel, an anomaly in a system with no major fluvial input or shelf canyons. The sediment supply instead has been provided by glacial erosion in the still-active Chugach-St. Elias orogen, and glacial transport across the shelf. Glaciation has periodically increased in the St. Elias Range since the Miocene, but began dominating erosion and spurred enhanced exhumation since the mid-Pleistocene transition, at approximately 1 Ma. Ice associated with this glacial intensification carved cross-shelf sea valleys that connect the St. Elias Range to the Surveyor Fan. The direct deposition of newly increased terrigenous sediment flux into the fan triggered the formation of the Surveyor Channel and its growth across the Surveyor Fan. Through the formation of the Surveyor Channel, climate events created three major differentiable sequences across the Surveyor Fan that we mapped using seismic-reflection profiles. The change in morphology observed throughout the sequences allows us to characterize the influence that a glaciated orogen can have in shaping margin processes and the sediment pathway from source to sink. We show that the large variation in sediment flux between glacial-interglacial cycles together with sea valley formation leads to a glacial shelf transport process not typical of a fluvial system. This glacial shelf transport along with the channel terminus in the Aleutian Trench makes the Surveyor Fan and Channel morphologically one of the most unique systems in the world.
English
Serial
Coverage:Geographic coordinates:
North:61.0332
West:-154.0811East: -140.0818
South:52.5940

Stratigraphy; Applied geophysics; Alaska; bathymetry; bottom features; Cenozoic; channels; climate effects; continental margin sedimentation; Deep Sea Drilling Project; DSDP Site 178; East Pacific; erosion; geophysical methods; geophysical profiles; geophysical surveys; glacial erosion; glaciation; Gulf of Alaska; Leg 18; lithostratigraphy; marine sediments; Neogene; North America; North Pacific; Northeast Pacific; ocean floors; orogeny; Pacific Ocean; Quaternary; reflection methods; Saint Elias Mountains; sedimentation; sediments; seismic methods; seismic profiles; southern Alaska; stratigraphic units; submarine fans; Surveyor Channel; Surveyor Fan; surveys; tectonics; terrigenous materials; Tertiary; United States; vertical seismic profiles; Yakutat Terrane;

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