Article

 

The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/articles/gb19f742q

Descriptions

Attribute NameValues
Creator
Abstract
  • Oxygen isotope data from planktonic and benthic foraminifera, on a high-resolution age model (44 ¹⁴C dates spanning 17,400 years), document deglacial environmental change on the southeast Alaska margin (59°33.32′N, 144°9.21′W, 682 m water depth). Surface freshening (i.e., δ¹⁸O reduction of 0.8‰) began at 16,650 ± 170 cal years B.P. during an interval of ice proximal sedimentation, likely due to freshwater input from melting glaciers. A sharp transition to laminated hemipelagic sediments constrains retreat of regional outlet glaciers onto land circa 14,790 ± 380 cal years B.P. Abrupt warming and/or freshening of the surface ocean (i.e., additional δ¹⁸O reduction of 0.9‰) coincides with the Bølling Interstade of northern Europe and Greenland. Cooling and/or higher salinities returned during the Allerød interval, coincident with the Antarctic Cold Reversal, and continue until 11,740 ± 200 cal years B.P., when onset of warming coincides with the end of the Younger Dryas. An abrupt 1‰ reduction in benthic δ¹⁸O at 14,250 ± 290 cal years B.P. likely reflects a decrease in bottom water salinity driven by deep mixing of glacial meltwater, a regional megaflood event, or brine formation associated with sea ice. Two laminated opal-rich intervals record discrete episodes of high productivity during the last deglaciation. These events, precisely dated here at 14,790 ± 380 to 12,990 ± 190 cal years B.P. and 11,160 ± 130 to 10,750 ± 220 cal years B.P., likely correlate to similar features observed elsewhere on the margins of the North Pacific and are coeval with episodes of rapid sea level rise. Remobilization of iron from newly inundated continental shelves may have helped to fuel these episodes of elevated primary productivity and sedimentary anoxia.
Resource Type
DOI
Date Available
Date Issued
Citation
  • Davies, M. H., A. C. Mix, J. S. Stoner, J. A. Addison, J. Jaeger, B. Finney, and J. Wiest (2011), The deglacial transition on the southeastern Alaska Margin: Meltwater input, sea level rise, marine productivity, and sedimentary anoxia, Paleoceanography, 26, PA2223, doi:10.1029/2010PA002051.
Journal Title
Journal Volume
  • 26
Journal Issue/Number
  • 2
Rights Statement
Funding Statement (additional comments about funding)
  • This work wasfunded by National Science Foundation Paleoclimate grant ATM‐0602395,National Science Foundation Geophysics grant EAR‐0711584, andNational Science Foundation Ocean Drilling grants OCE‐0242084 andOCE‐0351096.
Publisher
Peer Reviewed
Language
Replaces
Additional Information
  • description.provenance : Approved for entry into archive by Sue Kunda(sue.kunda@oregonstate.edu) on 2011-12-15T01:20:04Z (GMT) No. of bitstreams: 1 StonerJS.COAS.DeglacialTransitionSoutheastern.pdf: 1676712 bytes, checksum: 0663c32cef1dc4a3cb3ccc26e73ffcfb (MD5)
  • description.provenance : Made available in DSpace on 2011-12-15T01:20:04Z (GMT). No. of bitstreams: 1 StonerJS.COAS.DeglacialTransitionSoutheastern.pdf: 1676712 bytes, checksum: 0663c32cef1dc4a3cb3ccc26e73ffcfb (MD5) Previous issue date: 2011
  • description.provenance : Submitted by Deanne Bruner (deanne.bruner@oregonstate.edu) on 2011-12-13T22:16:32Z No. of bitstreams: 1 StonerJS.COAS.DeglacialTransitionSoutheastern.pdf: 1676712 bytes, checksum: 0663c32cef1dc4a3cb3ccc26e73ffcfb (MD5)

Relationships

Parents:

This work has no parents.

Items