983 resultados para Sodium sulfate
Resumo:
We have proposed a method of deducing the chemical compounds found in deep polar ice cores by analyzing the balance between six major ions (Cl-, NO3-, SO4**2-, Na+, Mg2+, and Ca2+). The method is demonstrated for the Holocene and last glacial maximum regions of the Dome Fuji and GRIP ice cores. The dominant compounds depend only on the ion balance and the sequence of chemical reactions. In priority order, the principle salts are calcium sulfate, other sulfates, nitrate, chloride, and carbonate. The chemical abundances deduced by this method agree well with the results of Raman spectroscopy on individual salt inclusions. The abundances in the ice cores are shown to reflect differences in climatic periods (the acidic environment of the Holocene versus the reductive environment of the last glacial maximum) and regional conditions (the marine environment of Antarctica versus the continental environment of Greenland).
Resumo:
Redox conditions and compositions of bottom sediments and sedimentary pore waters in the area of the hydrothermal vent in the Frolikha Bay (Baikal Lake) are under discussion. According to obtained results, the submarine vent and its companion spring nearby on the land originate from a common source. The most convincing evidence for their relation comes from proximity of stable oxygen and hydrogen isotope compositions in the pore waters and spring water. The isotope composition indicates meteoric origin of the pore waters, but their major- and minor element compositions have influence of deep water, which may seep through the permeable faulted crust. Although the pore waters near the submarine vent have specific enrichment in major and minor constituents, hydrothermal discharge at the Baikal bottom causes minor influence on water composition of the Baikal Lake, unlike freshwater lakes in rifts of the East Africa and North America.