Petrology of the Maku to Poldasht young lavas; Attitude to the olivine and bubbles size distribution

Dark young lavas from Ararat Volcano, in less than 1Ma ages, with diaclasic, aa and pahoho debies, are covered the Maku to Poldasht vast region. The unit rock type is basaltic to andesi-basaltic with idio-hype idiomorph plagioclase, clinopyroxene and olivine and has calc-alkaline affinities. These rocks are generated at within plate environment . ∆Nb factor in the rocks is similar to continental within plate flood basalts. The study on the CSD of olivine shows that nucleation rate was 4 to 5 times more rapid than growth rate. Also the slope of the curve that equals with -1/Gt, was -3 to -5, considering to standard growth speed for crystals, show the residence time of 60 to 90 years for such growth. The BSD on vesicles indicate that nucleation and growth rates were equal at the Maku basalts or growth was quicker than nucleation in some cases. The important point is that at the time unit the bubbles growth rate was 3 to 5 times more fast than olivine crystal growth which considering the basic composition of the Maku lavas it is predictable.