麻豆传媒

Scientific research defining paleo-environments and paleo-ice cover of the Arctic Ocean is essential to the interpretation of current day trends within these regions. In 2004, the crew aboard the NGCC Amundsen collected box cores at stations within the Amundsen Gulf chosen carefully with the help of multi-beam sonar images, and sub-bottom profiles. This particular study is an investigation of the foraminifera in box cores 209B and 215, which transect through the Amundsen Gulf.

Both box core 209B and 215 show signs of an extremely low sedimentation rate, representing the entire Holocene. Recent research on benthic foraminifera completed on the Beaufort shelf indicate a high sedimentation rate. Box core 209B was taken at a water depth of 241 m in the Amundsen Gulf. Foraminifera from box core 209B were dominated by agglutinated species, which are common among the sediments of the Arctic shelf and shallow seas. In the Late Holocene sediments (~1-5 cm interval) indicate less sea ice with few calcareous species in the sediment. Since anoxic conditions are not favorable to calcareous test preservation, this explains why other calcareous species were not more common in this core section. The presence of tntinnids near the surface indicate that there is a freshwater flux land no sea ice. Box core 215 is similar but has no foraminifera and a high concentration of sand, clay, and several large rock fragments near the base representing the glacial/interglacial boundary.

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Pages: 51
Supervisor: David Scott