VOLCANOCLASTIC ROCKS WITH THE BASIC-ULTRA BASIC INCLUSIONS FROM THE TRANSITION ZONE OF THE REYKJANES RIDGE (THE NORTHERN ATLANTIC)

The petrography, mineralogy, chemical compositions of rocky and minera l inclusions of tuffs and lavas were investigated. These rocks were dr agged during R/V ''Akademic Kurthatov'' and ''Michail Lomonosov'' expe ditions from the bottom of the transition zone of the Iceland shelf-Re ykjanes Ridge (depth 950-720 m). For the first time the mantle ultraba sic xenoliths were separated in icelandic region. The basaltic lavas p ossessed the alkaline high magnesium composition and high concentratio ns of gases and fluides. This fact was the cause of the formation of t he volcanic pipes at the depth between 500 and 600 m.