Time delay in pulsations of the nonthermal radiation of solar flares

The oscillations with a period of about 6 and 12 s in the nonthermal radiation of a solar flare occurred on November 5, 1992, are identified. The time-translated profiles of hard X-ray and microwave radiation flux are characterized by an anticorrelation. The specific features of the radiation fine time structure are interpreted using the model of the coronal magnetic mirror where fast magnetoacoustic modes are excited.     

The east-Siberian complex of SibIZMIR Solar Observatories

The Sayan Solar Observatory, the Tunkinskaya Radiophysical Observatory, and the Baikal Astrophysical Observatory of SibIZMIR have been described. Some results of the investigations carried out over the past years have been expounded. Clarifying solar activity mechanisms and the nature of solar magnetic fields, active regions and flares as well as solar wind are their main problems. In the interest of these investigations the Institute has initiated and developed laboratory-scale simulation of plasma processes.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.     

Analysis of the productivity of gold deposits of Amur province

By the amount of extracted placer and primary gold (~1300 t), Amur province is one of the major gold provinces of Russia. Its numerous placers yielded almost 1132 t Au in contrast to ~180 t from primary deposits. The central part of the province is most productive for placer and primary gold in comparison with the periphery. Native gold from placers has moderately high and high fineness, and its composition corresponds to that of gold from dominant gold–quartz and gold–quartz–sulfide deposits and occurrences. The preponderance of placer gold in gold production indicates significant prospects for discovery of new gold deposits.     

Geological structure, composition of ores and age of the Bamsk gold deposit, Amur region, Russia

The Bamsk gold-ore deposit is located in the Amur region, the Far East of Russia. It is confined to the Early Cretaceous volcanic-plutonic uplift of central type, located in the Stanov folded-clumpy Pre-Cambrian system. The deposit is presented by a series of gold-bearing quartz and carbonate-quartz vein-stringer zones. They are confined to the super-intrusive zone of the Nevachansk subvolcanic intrusion of sienite-porphyric composition. The mineralization is being controlled by zone of fractures developed in the autochthone ofthe Bamsk fault. Quartz, carbonates and sericite prevail in the composition of ores. The quantity of ore minerals doesn't exceed 1%～5%. Pyrite, chalcopyrite, galena and native gold are widely spread. Sheelite, gold and silver tellurides, sulphobismuthites, acanthite, sphalerite and cinnabar are less developed. Four stages of mineralization have been distinguished. Gold-sulphide-sulphosalt ore with tellurides of gold and silver is productive for gold. The following set of elements is typomorphic for the ores of the deposit: Au, Ag, Cu, Bi,Mo, Pb and Sb (W1, Pb1, Mo) -Cu- (Ag, Bi, Sb, Mn, W1, Pb2) form the vertical series of zoning. Rocks, enclosing the mineralization are exposed to the processes of listvenitization-beresitization. The processes of gumbeization and argillization are less manifested. The age of the gold mineralization, determined by Rb-Sr method on ore-accompanying minerals, is 130.6 Ma.     

Tokur gold ore–placer cluster in Amur Province: Geological–structural features and perspective of its development

The geological–structural features and gold-potential perspective of the Tokur ore–placer cluster in the Amur Province have been studied. This ore–placer cluster is a syncline composed of Paleozoic blackshale sequence, which is cut through by Late Paleozoic and Late Mesozoic intrusions. A granitoid massif is suggested at the depth on the basis of geophysical data. The cluster is distinguished by high productivity. Approximately 37 t gold from ore deposits, primarily from the Tokur deposit, and 60 t from placers have been mined out. The Tokur deposit is compared with the Natalka and Degdekan deposits from the Yana–Kolyma Province. Perspectives of the cluster area for large gold–quartz deposits and technogenic gold placers have been estimated.     

Role of wind and thermal forcing in the formation of the water circulation variability in the Japan/East Sea Central Basin in 1958–2006

Based on the numerical experiment on simulation of the Japan/East Sea (JES) water circulation response to the atmospheric forcing for 1958–2006, the analysis is made of its long-term variability in the JES Central Basin (CB). It was found that during the climatic year, the circulation remains cyclonic, strengthening in spring and weakening in autumn. The analysis of mean relative vorticity (MRV) at intermediate depths in the JES CB showed one that the spectrum of its interannual variability is formed mainly by oscillations of periods ～2, ～4 and ～5 years, and in the decadal range with ～10 and ～14 years. Along the depth, the spectral composition of MRV variability does not change, but there is a noticeable weakening of decadal variability amplitude, which does not occur with the 4- and 5-year oscillations. Using SVD-analysis, the connection is established between MRV variability, wind stress curl (WSC), as well as sensible heat flux. The strong connection between MRV and WSC is revealed in the range of 4–5 years, and in the decadal range (period is 10 years) the significant connection is with both WSC and air-sea temperature as a result of winter cooling and following deep convection.