• journal_title：Journal of Sedimentary Research
• Contributor：Christopher R. Blaeser ; Michael T. Ledbetter
• Publisher：SEPM Society for Sedimentary Geology
• Date：1982-
• Format：text/html
• Language：en
• Identifier：10.1306/212F8044-2B24-11D7-8648000102C1865D
• journal_abbrev：Journal of Sedimentary Research
• issn：1527-1404
• volume：52
• issue：3
• firstpage：755
• section：Articles

Forty-five core-top samples taken in the Vema Channel (southwest Atlantic) within the deduced boundaries of two important bottom-currents have been analyzed for the particle size distribution of the noncarbonate silt-size fraction. This was done in order to characterize the sediment beneath each water-mass. Using statistical and graphical methods it was found that sediment beneath the high-velocity Antarctic Bottom Water in the bottom of the channel exhibits the coarsest mean size, poor sorting, and a large percent of coarse silt left as a lag deposit; sediment beneath the overlying low-velocity North Atlantic Deep Water is marked by fine mean size, good sorting, no coarse silt, and a large percent of fine silt; sediment beneath the intervening transition zone is characterized by finest mean size, moderate sorting, largest percent fine silt, and a small lag component of coarse silt. The methods developed for delineating bottom-currents in the Vema Channel may be applied to a wide range of benthic oceanographic settings as well as the geologic record in order to examine relative paleovelocity fluctuations of major bottom-currents.