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The common mussel Mytilus galloprovincialis was selected as unique biomonitor species to implement a regional monitoring programme, the CIESM Mediterranean Mussel Watch (MMW), in the Mediterranean and Black Seas. As of today, and upon standardization of the methodological approach, the MMW Network has been able to quantify (137)Cs levels in mussels from 60 coastal stations and to produce the first distribution map of this artificial radionuclide at the scale of the entire Mediterranean and Black Seas. While measured (137)Cs levels were found to be very low (usually < 1 Bq kg(-1) wet wt) (137)Cs activity concentrations in the Black Sea and North Aegean Sea were up to two orders of magnitude higher than those in the western Mediterranean Basin. Such effects, far from representing a threat to human populations or the environment, reflect a persistent signature of the Chernobyl fallout in this area.

phyry copper ore-magmatic system have remained debatable.Under the current economic conditions of northeastern Russia, most of the known porphyry Cu-Mo deposits and occurrences are not promising for economic development. However, the metallogenic belts and zones where these deposits are located are extremely important in forecasting of potentially economic highgrade epithermal gold-silver deposits.At different times, we have studied the metallogenic belts and ore districts considered below. The most recent results of thermobarogeochemical studies were obtained only in 2005. In preparing this paper, we pursued the following goals: (i) to consider the current state of the problem and to summarize the previously obtained results, (ii) to outline the geodynamic settings favorable for formation of porphyry-type Au-bearing Cu-Mo deposits in the Northeast of Russia and the main trends in their spatial distribution, (iii) to review the geology of typical deposits and the ore composition therein, (iv) to study ore formation conditions in a comparative aspect, and (v) to clarify the relationships between epithermal Au-Ag and porphyry Cu-Mo ores in the common ore-forming system. GENERAL OUTLINE OF PORPHYRY-TYPE DEPOSITSPorphyry-type deposits are the main worldwide source of Cu and Mo; Au, Ag, and platinum group and some other rare metals are recovered from this ore as by-products. Porphyry deposits are accompanied by Abstract -By analogy with other metallogenic belts of the Circum-Pacific ring, the metallogenic belts in the Northeast of Russia are promising for discovery of large and superlarge porphyry-type Au-Cu-Mo deposits. The spatial distribution of these deposits is controlled by intrusive domes in Middle Paleozoic, Late JurassicEarly Cretaceous, and Late Cretaceous volcanic belts. New data on formation conditions and sources of ore matter are presented in this paper with respect to the deposits of the Baim and Koni-P'yagina ore districts of the Oloi and Uda-Murgal metallogenic belts. Some aspects of a geological and genetic model of the porphyry copper ore-magmatic system are discussed.