Radium and barium at GEOSECS stations in the Atlantic and Pacific

228Ra/226Ra and 226Ra/Ba ratios in the Western Mediterranean Sea: Barite formation and transport in the water column

“…The 226 Ra/Ba ratio was found to be very uniform within these different basins (i.e. 2.3 dpm µmol -1 ; Chan et al, 1976;Foster et al, 2004). Low values have also been observed at the OFP site off Bermuda in the Atlantic Ocean, but only in the upper 500 m of the water column (van Beek et al, 2007).…”

The trace element geochemistry of marine biogenic particulate matter

“…The variation of the elemental ratios in the settling particulates, due to differences in the extent of surface recycling of nutrients, has been described in section IV-3 by an enrichment interpreted using a steady-state vertical advection-diffusion model (Wyrtki,1962;Craig,1969) which has been successfully applied to open ocean trace element profiles in the Pacific (Chan et al,1976;Boyle el al.,1977;Measures et al,1980). Data for each species are fit to the one-dimensional differential equation:…”

“…Ra and is one of the first systematically determined trace elements whose distribution indicates involvement in biological cycling (Chow and Goldberg,1960;Bacon and Edmond,1972;Chan et al,1976Chan et al, ,1977. The primary input fluxes and distribution of Ba used in the box model are presented in Table IV-14.…”

“…It has been shown for Ba and 226Ra (Edmond,1970;Chan et al,1976) that the deep enrichment of these elements, which is seen to persist in the Antarctic, is inconsistent with their sole incorporation in a carbonate carrier. Examination of the biogenic CaCO 3 phases in this study and in the literature (Thompson and Bowen, 1968;Boyle,1980) clearly demonstrates that they do not serve to transport significant Ba from the surface ocean.…”

Barium isotope fractionation in the global barium cycle: First evidence from barium minerals and precipitation experiments

“…Continental detrital contributions of Ba to marine sediments are not easily corrected for due to uncertainties in the estimates of the terrigenous Ba/Al ratio (Klump et al, 2000;Reitz et al, 2004). In the modern ocean, dissolved Ba shows a variable concentration and a nutrient-type behavior (Chan et al, 1976). As a nonconservative element, it has a relatively short residence time of 11 kyr (Edmond et al, 1979).…”