Lake Biwa and the ocean: geochemical similarity and difference

摘要: The average composition of water, bottom sediments, manganese (Mn) crusts, and Mn concretions from Lake Biwa (the largest freshwater lake in Japan) are re-examined, conjunction with those seawater, oceanic pelagic clay, deep-sea nodules. purpose is to gain additional insights into the geochemical behaviors elements ocean, which quite different ionic strength (or salinity), pH, water residence times, sediment accumulation rates, carbon fluxes redox potential sediments. Excluding a few millimeters oxic surface sediment, there no appreciable sediments due reducing condition there. Consequently, other B-type cations [such as iron (Fe), gallium (Ga), copper (Cu), lead (Pb), cobalt (Co), tin (Sn), bismuth (Bi), subshell valence electron configuration d1−10] also less concentrated than clay. In turn, have much higher dissolved concentrations ocean. rare earth (REE) mainly form organic complexes carbonate REE mostly associated detritus aluminosilicate phases but phosphate Fe oxide clearly separated marine nodules crusts not Biwa. Useful parameters such enrichment factor (EAl) logarithms distribution coefficient (log Kd) between solid liquid were estimated both systems for further discussions.