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The authigenic suspended matter formation in the ocean
O LR (1986)33 (12)
C. Chemical Oceanography
86:6874 Tambiev, S.B., 1986. The authigenic suspended matter formation in the ocean. Okeanologiia, 26(2):224-233. (In Russian, English abstract.) During bubble flotation and suspended aggregate formation, seawater pH decreased and alkalinity increased; dissolved Si and P concentrations generally decreased as well. SEM examination revealed aggregate composition by films and flakes ranging in size from < 1 to 200-300 t~m. A physico-chemical mechanism of aggregate formation is proposed; influences on organic matter fluxes and sedimentary processes are discussed. (slr)
C180. Geochemistry, biogeochemistry (see also D-SUBMARINE GEOLOGY AND GEOPHYSICS) 86:6875 Frost, C.D., R.K. O'Nions and S.L. Goldstein, 1986. Mass balance for Nd in the Mediterranean Sea. Chem. Geol., 55(1-2):45-50. Dept. of Earth Sci., Univ. of Cambridge, CB2 3EQ, UK.
86:6876 Goldberg, E.D., Vern Hodge, Peter Kay, Martha Stallard and Minoru Koide, 1986. Some comparative marine chemistries of platinum and iridium. Appl. Geochem., 1(2):227-232. Iridium has seawater concentrations about one hundred times less than those of platinum as a consequence of its weaker complexing abilities with halides and a stronger tendency to hydrolyze. Both are enriched in some ferromanganese minerals compared to palladium. Platinum and iridium are probably oxidized during mineral formation from the divalent and trivalent states, respectively, to the tetravalent ones. The pelagic sediment contents of both are related to the manganese contents. For higher platinum contents of the authigenic ferromanganese minerals the Pt/Ir ratios approach the seawater ratio, suggesting little dilution by platinum and iridium in detrital minerals. Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA. 86:6877 Guo, Laodong, Jinbao Guo and Faxi Li, 1986. Physicochemical processes of silicates in the estuarine region. V. A simulation experiment on the formation of authigenic silicate minerals by adsorption. Acta oceanol, sin. (English version), 5(1):70-75. Authigenic silicate minerals were synthesized under laboratory conditions, demonstrating that there may
1007
exist a geochemical process of authigenic silicate mineral formation by coagulation, adsorption, structural rearrangement and crystallization from dissolved substances in estuarine and marine environments. Results show that authigenic silicate minerals are significant in the chemical removal of dissolved silica from seawater. Dept. of Oceanogr., Xiamen Univ., Xiamen, People's Republic of China. 86:6878 Henrich, Rodiger and Gerold Wefer, 1986. Dissolution of biogenic carbonates: effects of skeletal structure. Mar. Geol., 71(3-4):341-362.
Dissolution of biogenic shallow-water carbonates exposed on deep-sea moorings indicates that skeletal structure is important for the rate of disintegration of biogenic carbonates, in addition to mineralogy and grain size of particles. Organic coatings, intraskeletal pore spaces, and sizes and shapes of individual crystallites in the skeletons may be more important than carbonate mineralogy and particle size in some cases. The presence of internal sediments, cement aggregates and natural contaminations, and of diatoms incorporated during growth into carbonate skeletons, strongly influence the disintegration of the skeletal materials. GeolPalaontol. Inst. und Mus., Univ. Kiel, Olshausenstrasse 40, D-2300 Kiel, FRG. 86:6879 Hong, Huasheng and D.R. Kester, 1986. Redox state of iron in the offshore waters of Peru. Limnol. Oceanogr., 31(3): 512-524.
Up to 40 nmol kg-t of Fe(II) was detected in the bottom water at 5-10 km offshore and decreased markedly upward in the water column and with distance offshore. Elevated Fe(II) concentrations near the sea surface and a did change were probably due to photochemical reactions involving iron. Total iron levels were >300-500 nmol kg-~ in the surface and the bottom water at 5-6 km offshore. About 80-90% of the iron was in particulate form, indicating a substantial input from continental dust and shelf sediments. The total iron level decreased considerably within 35 km of the coastline and the iron seemed to be trapped on the shelf. Dept. of Oceanogr., Box 1085, Xiamen Univ., Fujian, People's Republic of China. 86:6880 Li, Cuizhong, 1986. Geoclmmistry of trace elements in deep--sea sediments of the South China Sea. Scientia sin., (B)29(1):85-95.
A factor analysis of data obtained from sediment surface samples collected at depths of 449-4380 m
C. Chemical Oceanography
86:6874 Tambiev, S.B., 1986. The authigenic suspended matter formation in the ocean. Okeanologiia, 26(2):224-233. (In Russian, English abstract.) During bubble flotation and suspended aggregate formation, seawater pH decreased and alkalinity increased; dissolved Si and P concentrations generally decreased as well. SEM examination revealed aggregate composition by films and flakes ranging in size from < 1 to 200-300 t~m. A physico-chemical mechanism of aggregate formation is proposed; influences on organic matter fluxes and sedimentary processes are discussed. (slr)
C180. Geochemistry, biogeochemistry (see also D-SUBMARINE GEOLOGY AND GEOPHYSICS) 86:6875 Frost, C.D., R.K. O'Nions and S.L. Goldstein, 1986. Mass balance for Nd in the Mediterranean Sea. Chem. Geol., 55(1-2):45-50. Dept. of Earth Sci., Univ. of Cambridge, CB2 3EQ, UK.
86:6876 Goldberg, E.D., Vern Hodge, Peter Kay, Martha Stallard and Minoru Koide, 1986. Some comparative marine chemistries of platinum and iridium. Appl. Geochem., 1(2):227-232. Iridium has seawater concentrations about one hundred times less than those of platinum as a consequence of its weaker complexing abilities with halides and a stronger tendency to hydrolyze. Both are enriched in some ferromanganese minerals compared to palladium. Platinum and iridium are probably oxidized during mineral formation from the divalent and trivalent states, respectively, to the tetravalent ones. The pelagic sediment contents of both are related to the manganese contents. For higher platinum contents of the authigenic ferromanganese minerals the Pt/Ir ratios approach the seawater ratio, suggesting little dilution by platinum and iridium in detrital minerals. Scripps Inst. of Oceanogr., La Jolla, CA 92093, USA. 86:6877 Guo, Laodong, Jinbao Guo and Faxi Li, 1986. Physicochemical processes of silicates in the estuarine region. V. A simulation experiment on the formation of authigenic silicate minerals by adsorption. Acta oceanol, sin. (English version), 5(1):70-75. Authigenic silicate minerals were synthesized under laboratory conditions, demonstrating that there may
1007
exist a geochemical process of authigenic silicate mineral formation by coagulation, adsorption, structural rearrangement and crystallization from dissolved substances in estuarine and marine environments. Results show that authigenic silicate minerals are significant in the chemical removal of dissolved silica from seawater. Dept. of Oceanogr., Xiamen Univ., Xiamen, People's Republic of China. 86:6878 Henrich, Rodiger and Gerold Wefer, 1986. Dissolution of biogenic carbonates: effects of skeletal structure. Mar. Geol., 71(3-4):341-362.
Dissolution of biogenic shallow-water carbonates exposed on deep-sea moorings indicates that skeletal structure is important for the rate of disintegration of biogenic carbonates, in addition to mineralogy and grain size of particles. Organic coatings, intraskeletal pore spaces, and sizes and shapes of individual crystallites in the skeletons may be more important than carbonate mineralogy and particle size in some cases. The presence of internal sediments, cement aggregates and natural contaminations, and of diatoms incorporated during growth into carbonate skeletons, strongly influence the disintegration of the skeletal materials. GeolPalaontol. Inst. und Mus., Univ. Kiel, Olshausenstrasse 40, D-2300 Kiel, FRG. 86:6879 Hong, Huasheng and D.R. Kester, 1986. Redox state of iron in the offshore waters of Peru. Limnol. Oceanogr., 31(3): 512-524.
Up to 40 nmol kg-t of Fe(II) was detected in the bottom water at 5-10 km offshore and decreased markedly upward in the water column and with distance offshore. Elevated Fe(II) concentrations near the sea surface and a did change were probably due to photochemical reactions involving iron. Total iron levels were >300-500 nmol kg-~ in the surface and the bottom water at 5-6 km offshore. About 80-90% of the iron was in particulate form, indicating a substantial input from continental dust and shelf sediments. The total iron level decreased considerably within 35 km of the coastline and the iron seemed to be trapped on the shelf. Dept. of Oceanogr., Box 1085, Xiamen Univ., Fujian, People's Republic of China. 86:6880 Li, Cuizhong, 1986. Geoclmmistry of trace elements in deep--sea sediments of the South China Sea. Scientia sin., (B)29(1):85-95.
A factor analysis of data obtained from sediment surface samples collected at depths of 449-4380 m