Deep-Sea Research II 48 (2001) 4323–4383 Benthic remineralization and burial of biogenic SiO 2 , CaCO 3 , organic carbon, and detrital material in the Southern Ocean along a transect at 1701 West F.L. Sayles a, *, W.R. Martin a , Zanna Chase b , R.F. Anderson b a Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA b Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, USA Received 6 July 2000; received in revised form 7 November 2000; accepted 24 March 2001 Abstract We investigated the composition, recycling, and mass accumulation rates of sediments along a transect in the Southern Ocean located from 661Sto571Sat1701W. This transect also corresponds to the location of a sediment trap mooring line. The sediments at the seven sites studied range from largely terrigenous material to nearly pure (>90%) biogenic silica. CaCO 3 is a minor but persistent component at most sites. Mass accumulation rates have been determined on the basis of excess 230 Th in the sediments, i.e., 230 Th- normalized accumulation rates. The inﬂuence of redistribution of sediments on the sea ﬂoor has been estimated from 14 C analyses. The recycling of material delivered to the sediments has been characterized on the basis of pore water studies that make extensive use of both in situ sampling and shipboard extractions. The inﬂuence of the highly variable rates of input of particulate matter that characterize much of the Southern Ocean upon pore water gradients and ﬂuxes across the sediment water interface has been considered. We ﬁnd only poor correspondence between BSiO 2 burial fraction (=burial/particulate ﬂux), a quantiﬁable measure of preservation eﬃciency, and BSiO 2 particulate rain along the transect. However, preservation does appear to be closely linked to a combination of sedimentation rate and particulate rain. The burial fraction of BSiO 2 is small relative to benthic rain (5–19%). Despite the small fraction buried, burial ﬂux normalized to (sedimentation rate) 1/2 appears to provide a very consistent means of predicting benthic particulate rain over a large range of rain rates, including data from a number of diﬀerent studies and environments. At sites with BSiO 2 rain X250mmolm 2 yr 1 the average diﬀerence between predicted and observed rain is 25–30%. Such rain rates occur in many marine areas, particularly the Southern Ocean, with the result that this relationship potentially provides a means of estimating BSiO 2 benthic rain over prolonged periods in the past on the basis of readily measured sediment parameters. *Corresponding author. E-mail address: fsayles@whoi.edu (F.L. Sayles). 0967-0645/01/$-see front matter r 2001 Elsevier Science Ltd. All rights reserved. PII:S0967-0645(01)00091-1