Silicate and opal in the Ross Sea

• Main Authors: Ledford-Hoffman, P A, DeMaster, David J, Nittrouer, Charles A
• Format: Dataset
• Language: English
• Published: PANGAEA 1986
• Subjects: BC; Box corer; Depth; bathymetric; bottom/max; sediment/rock; top/min; LATITUDE; Ledford; LONGITUDE; Opal; biogenic silica; extraction; DeMaster; 1981; Sample; optional label/labor no; Silicate; Silicon Cycling in the World Ocean; SINOPS; Antarctic; The Antarctic; Ross Sea; Sulzberger Bay; Antarc*
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.58017; https://doi.org/10.1594/PANGAEA.58017

Thirty-five box cores were collected from the continental shelf in the Ross Sea during cruises in January and February, 1983. Pb-210 and Pu-239, 240 geochronologies coupled with biogenic-silica measurements were used to calculate accumulation rates of biogenic silica. Sediment in the southern Ross Sea accumulates at rates ranging from <=0.6 to 2.7 mm/y, with the highest values occurring in the southwestern Ross Sea. Biogenic-silica content in surface sediments ranges from 2% (by weight) in Sulzberger Bay and the eastern Ross Sea to 41% in the southwestern Ross Sea. Biogenic-silica accumulation in the southwestern Ross Sea averages 2.7 * 10**-2 g/cm**2/y and is comparable to accumulation rates in high-productivity, upwelling environments from low-latitude continental margins (e.g., Gulf of California, coast of Peru). The total rate of biogenic-silica accumulation in the southern Ross Sea is approximately 0.2 * 10**14 g/y, with most of the accumulation occurring in basins (500-1000 m water depth). If biogenic-silica accumulation in the southern Ross Sea continental shelf is typical of other basins on the Antarctic continental shelf, as much as 1.2 * 10**14 g/y of silica could be accumulating in these deposits. Biogenic-silica accumulation on the Antarctic continental shelf may account for as much as a fourth of the dissolved silica supplied to the world ocean by rivers and hydrothermal vents.