Simulation model of basic components of the Okhotsk Sea ecosystem

A simulation system which models the dynamics of major groups of plankton in the Okhotsk Sea, taking into account the most important abiotic environmental factors and the complex of external influence, is devised. A model study of the seasonal variability and spatial distribution of these groups has been carried out. The simulation complex consists of blocks which represent complete program algorithms of separate processes: the large-scale water circulation in the Okhotsk Sea, the formation of salinity, temperature conditions, spatial-temporal dynamics of phytoplankton, and the dynamics of macroplankton and mesoplankton.Translated by M. M. Trufanov.     

Intergranular trace elements in mantle xenoliths from Russian Far East: Example for mantle metasomatism by hydrous melt

Based on both major and trace element chemistry, the occurrence of the intergranular component in mantle-derived xenoliths from far eastern Russia has been constrained. Whole-rock trace element measurements of one xenolith show apparent negative anomalies in Ce, Th, and high field strength elements on normalized trace element patterns. The trace element pattern of the whole rock differs from those of constituent minerals, indicating that the anomalies in the whole rock are attributable to the presence of an intergranular component. That assumption was confirmed using in situ analysis of trace elements in the intergranular substance and melt inclusion using laser ablation inductively coupled plasma–mass spectrometry. Both the intergranular component and the melt inclusions have identical trace element patterns, which mean that these materials are a cognate metasomatizing agent. The anomalies are regarded as mantle metasomatism related to an aqueous fluid. Hydrous minerals were observed on the wall of the melt inclusions using micro-Raman spectroscopy, indicating that the melt inclusions contained a large amount of water. Thus, this study reveals a trace element composition of a hydrous metasomatizing agent in the mantle.