Summary. In the central Vetreny Poyas, SE Fennoscandian shield, an areally extensive 110 m deep lava lake is exposed consisting of remarkably fresh differentiated komatiitic basalt. Age of rocks-(Sm-Nd isochrone) is 2410±34 Ma for whole rock samples, olivine, augite and pigeonite separates. For the first time authors have found primary inclusions in chromites from cumulate zone (Puchtel et al., 1996). They were research in Institute of geology Karelian research centre RAS. Primary inclusions in chromites consist more of Mg, Fe, Ca and less in Al, Si, and Na than matrix rocks from cumulate zone of lava lake. They composition correlated with breccia komatiitic basalt of top lava lake. New date shows that primary high - magnesian magma of volcanic rocks of Vetreny Poas is low-magnesian basaltic part of komatiitic series. It is not boninitic rocks as was published by E. Sharkov (2004).