Palaeoceanography of the Northeastern Pacific Ocean off Vancouver Island, Canada ...

• Main Author: McKay, Jennifer Lynn
• Format: Text
• Language: English
• Published: University of British Columbia 2009
• Subjects: glacier*
• Online Access: https://dx.doi.org/10.14288/1.0052403; https://doi.library.ubc.ca/10.14288/1.0052403

Marine sediment cores from the continental margin off Western Canada (48° to 50°N, 125 to 128°W) yield evidence of dramatic changes in oceanographic conditions over the last 16 kyr. During the late Glacial the accumulation of marine organic matter was greatly reduced. This reflects low primary and export production because glacial-mode atmospheric circulation did not drive coastal upwelling. At the start of the Boiling warm period (-14.3 kyr B.P.), and coincident with the retreat of glaciers from the continental shelf, there was a substantial increase in the burial of organic matter. However, much of this material was "old" terrestrial organic detritus derived in part from the erosion of shelf sediments. It was not until the Allerod (-13.5 to 12.6 kyr B.P.) that the accumulation of marine organic matter increased substantially. Other paleoproductivity proxies (i.e., % biogenic Ba, % opal and alkenone abundances) also indicate very high marine productivity at this time. Since primary production in the region ...