Variations in particle alignment and size in sediments of the Vema Channel record Antarctic bottom-water velocity changes during the last 400 000 years.

• Main Authors: Ledbetter, M. T., Ellwood, B. B.
• Format: Text
• Language: unknown
• Published: LSU Digital Commons 1982
• Subjects: Antarctic; Antarc*
• Online Access: https://digitalcommons.lsu.edu/geo_pubs/849

The anisotropy of magnetic susceptibility (AMS) and mean particle size in the silt fraction has been measured in surface sediments and selected cores from the Vema Channel. Results show that a function which represents magnetic grain, long-axis alignment is highly correlated with variation in mean size of the carbonate-free silt fraction. An increase in alignment with increase in particle size reflects an increase in bottom-water velocity. This correlation has been used to infer fluctuation in Antarctic Bottom water (AABW) velocity during the last 400 000 years. The period of highest inferred bottom-water velocity resulted in a late Pliocene hiatus marked by a buried manganese pavement.-from Authors