121 resultados para 372.218
Resumo:
The Br/Cl, Li/Cl and B/Cl ratios and boron isotope compositions of hypersaline pore fluids from DSDP Sites 372 and 374 were measured in an attempt to evaluate the origin of the brines. In Site 374 the relationships between the Cl concentrations (up to 5000 mM) and Br/Cl (~0.012), Na/Cl (as low as 0.1), B/Cl (0.0025), and d11B values (43-55?) of the deep pore water between 380 and 405 mbsf, located within the Messinian sediments, reflect remnants of ~65-fold evaporated sea water. The original evaporated sea water was modified by: (1) dilution with overlying or less saline water by about 30%; and (2) slight dissolution of NaCl evaporites. The variations in d11B show a continuous increase in d11B values with depth in Site 374, up to 66.7? at a depth of 300 mbsf (Upper Pliocene marl sediments). The conspicuous 11B enrichment trend is consistent with elemental boron depletion, which was calculated from the expected boron concentrations of evaporated sea water with corresponding Br/Cl and Na/Cl ratios. Li/Cl variations also show a depletion of Li relative to evaporated sea water. The apparent depletions of B and Li, as well as the 11B enrichment, reflect uptake of these elements by clay minerals at low water/sediment ratios.
Resumo:
A description is given of the taxa sorted out of the zooplanktion and mikronekton material of the 1st German Antarctic Expedition 1975/76 by the Kiel sorting center. The methods employed in the sorting center are describined in detail. Notes for further use of the material are also given.