The interrelation of vulcanites with bedding granitoids in the north-east bank of the Lekhtin structure (Northern Karelia) are described. The conducted investigation shows that in the base of the Okhtinsk strata cut the ultrabasic komatiite-series metamorpihzed vulcanites are bedding. For the first time at the Baltic craton the direct interrelations of lopian volcanic-origin-sedimentary complex of greenstone belts with the basement gneiss-granitoids are established, which are expressed by the weathering profile with the age 2.8 mlrd. years.