The isotope-ratios of sulfur-components in several sedimentologically different cores of recent marine sediments from Kiel Bay (Baltic Sea) were investigated. In addition, quantitative determinations were made on total sulfur, sulfate, sulfide, chloride, organic carbon, iron and watercontent in the sediment or in the pore-water solution.The investigations gave the following results: 1. The sulfur in the sediment (about 0,~--2~ of the dry sample) was for the most part introduced into the sediment after sedimentation. This confirms the results of KA~LAN et al. (1968). The yield of Sulfur from organic material is very small (in our samples about g--10'~ of the total sulfur in the sediment). 2. The sulfur bound in the sediment is taken from the sulfate of the interstitial water. During normal sedimentation, the exchange of sulfate by diffusion significant for changes in the sulfur-content goes down to a sedimentdepth of 4--6 era. In this way the sulfate consumed by reduction and formation of sulfide or pyrite is mostly replaced. The uppermost layer of the sediment is an partly open system for the sulfur. The diagenesis of the sulfur is allochemieal. 8. The isotope-values of the sediment-sulfur are largely influenced by the sulfur coming into the sediment by diffusion and being bound by bacteriological reduction. Due to the prevailing reduction of 8~S and reverse-diffusion of sulfate into the open sea-water, an 32S enrichment takes place in the uppermost layer of the sediment. ~34S-values in the sediment range between --15 and --85 ~ while seawater-sulfate has + 20 ~ No relationship could be established between sedimentological or chemical changes and isotope-ratios. In the cores, successive sandy and clayly layers showed no change in the &values. The sedimentation rate, however, seems to influence isotope-ratios. In one core with low sedimentationrates the ~334S-values varied between --29 and --88 ~ while cores with higher sedimentationrates showed values between --17 and --24 ~ S22 M. HARTMANN U. H. NIELSEN --334S-Werte in rezenten Meeressedinaenten4. As sediment depth increases, the pore-water sulfate shows decreasing concentrations (in a depth of 30~40 cna we found between 9,0 and 70~o of the seawater-values), and increasing c3z4S-values (in one case reaching more than -k 600/00). The concentration of sulfide in the pore-water increases with sedinaent-depth (reaching 80 nag S/I in one case). The (~34S-values of the pore-water-sulfide in all cores show increases paralleling the sulfate sulfur, with a nearly constant ~-distance of 50-~60~ in all cores. This seems to confirm the genetic relationship between the two components. R6sum6Les rapports isotopiques de divers compos6s du soufre (S total dans le s6diment, sulfate et H2S en solution interstitielle) ont 6t6 mesur6s dans plusieurs earottes de s6diments marins r6cents, provenant de la ,< Kieler Bueht >> (baie de Kiel, Met baltique occidentale).En plus, les teneurs quantitatives en soufre total, sulfate, sulfure, chlorure, carbone organique, fer ct H~O dans...
Only a few S isotope data from atmospheric prei5pitates are available. These results demonstrate the possibility t o discriminate between sulfur burdens frdm different natural and/or anthropogenic sources. The a3*S patterns of the major suppliers of atmospheric sulfur are discussed., Their 6 ranges overlap so completely that we cannot use S isotope data of atmospheric sampIes to calculate the net contribution rates from the individual sources at a global scale. For selected areas, however, such conclusions can frequently be drawn. The most reliable results are t o be expec5ed from areas with only two (at maximum three) major sulfur suppliers with well known S isotopic composition and large 6 difference between the individual sources. Limitations are given
The isotope ratios of various sulphur components (total sulphur content in the sediment, sulphate and H(2)S in the pore-water) were measured in a number of cores from recent marine sediments taken from the Kieler Bucht (Kiel Bay) region in the western Baltic Sea. Additionally, the quantitative contents of total sulphur, sulphate, sulphide, chloride, organic carbon, iron and water in the sediment and in the pore-water solutions, respectively, were determined. These investigations provided the following results: 1. The sulphur contained in the sediment (∼ 0.3-2% of the dry sample) was for the most part introduced only after sedimentation. This confirms the deliberations of Kaplan et al. [The Distribution and Isotopic Abundance of Sulfur in Recent Marine Sediments off Southern California, Geochim. Cosmochim. Acta 27, 297 (1963)]. The organic substance contributes to the sulphur content of the sediment only to an insignificant degree (in our samples with ∼5-10% of the total sulphur). 2. The sulphate in the pore-waters has been identified as a source for sulphur in the sediment. During normal sedimentation, the exchange of sulphate by diffusion significant for changes in the sulphur content goes down to a sediment depth of 4-6 cm. In this process, the sulphate consumed by reduction and formation of sulphide or pyrite is mostly replaced. The uppermost sediment layer thus represents a partially open system for the total sulphur. The diagenesis of the sulphur is allochemical. At depths below 4-6 cm, we are dealing with a closed system. The further diagenesis of sulphur here is isochemical. 3. The isotope values of the sediment sulphur are influenced primarily by sulphur which comes into the sediment by diffusion and which is bound by subsequent bacteriological reduction as either sulphide or pyrite. As a consequence of the prevailing reduction of (32)S and reverse-diffusion of sulphate into the open sea water, a (32)S enrichment takes place in the uppermost layer of the sediment. The δ(34)S values in the sediment range in general between-15 and-35‰, while seawater sulphate is+20‰. No relationship could be established between sedimentological or chemical changes and isotope ratios. In the cores, successive sandy and clayish layers showed no change in the δ(34)S values. However, the sedimentation rate seems to influence δ(34)S values. In one core with relatively low sedimentation rates, the δ(34)S values varied between-29 and-33‰, while cores with higher sedimentation rates showed values between-17 and-24‰. 4. As sediment depth increases, the pore-water sulphate shows, as expected, decreasing concentrations (in a depth of 30-40 cm, we found between 20 and 70% of the seawater values), and increasing δ(34)S values (in one case reaching more than+60‰). The concentration of sulphide in the pore-water increases, however, with sediment depth (to various extents, reaching 80 mg S per litre in one case). The δ(34)S values of the pore-water sulphide in all cores show increases paralleling the sulphate sulphur, with a nearly constan...
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