Vol. 40 No. 1 (209) (2006)

On the basis of mineralogo-paragenetic or gemological (gem-stone) phases within the bounds of Undersevan zone of ofiolite association of rocks are suggested factors of the forecast, criteria of search and attributes of genetic types of mineralization. In connection with ofiolites of Armenia it is obviously possible to draw gemologists, search-geologists and explorer-geologists attention to the real perspectives of estimation of scales displays of gem-stone raw materials and to put them forward for practical application.

In this paper the quantitative assessment of aftershocks distribution for the Spitak earthquake in 1988 with magnitude M=7.0 is presented, to define the catalogue of declusterisation parameters. Comparing the released summary energy and earthquakes number before the main shock quiescence period with the same period after aftershocks, the aftershocks' real continuation period has been assessed. Received results for selected area has been compared with empirical equations of Omari and Utsu-Seki.

Water-resources characteristics of Lake Sevan are closely connected with the development phases of problems of the Lake. In the article are give descriptions which have been obtained due to statistical analysis and summarization of annual water balance of the lake and other water-resources activities. In the article also are given results of water use of the lake, also description of general elements of water balance, evaporation, and natural runoff (active output) of the lake, which depends on changes of its morphometry.