Late Jurassic-Neocomian volcanism of the northern Okhotsk region: Geology,tectonic settings,and mineralization

The paper deals with new data on the geology, geochronometry, and petrogeochemistry of the Upper Jurassic-Neocomian basaltic andesites constituting the base of the Cretaceous volcanogenic section in the northern Okhotsk region. The geochronometric data confirm the Late Jurassic-Neocomian age of these rocks (147–138 Ma, K-Ar method). Their characteristic features provide grounds for considering these rocks as fragments of the Uda volcanic belt. The comparison of the petrogeochemical characteristics with similar parameters of other different-age tectonic structures of the region under consideration that were formed in different geodynamic environments (intracontiental and continental marginal volcanogenic belts, island arcs) revealed similarity between the conditions of the formation of the Late Jurassic-Neocomian (Uda belt) and Albian-Cenomanian (Okhotsk-Chukotka belt) volcanics: both characterize continental marginal environments. It is assumed that the Late Jurassic-Neocomian volcanism associates with Au-Ag mineralization, which is also expected in other similar although poorly known volcanic structures.     

Granitoid formation time in the Main Kolyma Batholith Belt: Coordination of geological data and isotopic dating results (Northeast Asia)

It is shown that the granitoids of the Main Kolyma Batholith Belt do not penetrate into the Upper Jurassic deposits of the Yana–Kolyma mesozoids. The applicability of U–Pb SHRIMP zirconometry to the Mesozoic period of geological history is subject to critical analysis. It is concluded that analytical limitations preclude the solution of the concordance–discordance alternative of the obtained datings in the Mesozoic U–Pb isotopic systems by computational approaches. The U–Pb isotopic system is established as highly sensitive to the superimposed processes. Based on the reconciliation of the U–Pb, Rb–Sr, Ar–Ar, and K–Ar geochronometric data, the granitoids of the Kolyma Main Batholith Belt intruded 170–160 Ma ago, while their isotopic systems were transformed 150–140, 135–125, and 100–80 Ma ago. The local SHRIMP zirconometry combined with other isotopic methods can be applied to date igneous rocks by the relic dates, to set the time of intrusion into their isotopic systems, and to predict thermal events not identified yet. The U–Pb SHRIMP zirconometry should not be considered as arbitrary.     

Characteristics of coastal phytoplankton near Cape Tastubec (northern Aral Sea), September 1993

The species composition, population density, biomass and main functional characteristics of the phytoplankton community near Cape Tastubec, northern Aral Sea in September 1993 were investigated. The characteristics investigated were daily primary production, decomposition, and photosynthetic intensity. The data indicate that certain changes in the structure and function of the phytoplankton have recently taken place.     

Studying climate-related yield fluctuations of basic grain crops and their qualitative assessment under new socioeconomic conditions of the Russian Federation

Regularities of variability of grain crop yield by grain planting regions of the Russian Federation related to farming standards and a change in climatic conditions in the Soviet (1960–1990) and post-Soviet (1991–2008) periods are studied. The revealed regularities of the climate-related variability of the grain crop yield will be used in the process of adaptation of the weather-yield model to the present levels of the yield.     

Effect of dietary docosahexaenoic acid on lipogenesis and lipolysis in black sea bream, Acanthopagrus schlegeli

1 IntroductionIt is well known that varying dietary fatty acidprofile affects the tissue fatty acid composition and e-ven the growth performance in fish ( Bell et al.,2002; Figueiredo -Silva et al., 2005; Harel andPlace, 2003; Schulz et al., 2005; Tocher et al.,2003). Docosahexaenoic acid (DHA), an importantessential fatty acid for marine species, has the effectnot only on the fatty acid profile of fish body tissue,but also on biological and physiological conditions(Ishizaki et al., 2000; …