Genesis of alkalic rocks in Ural

As a rule, infiltrational metasomatism in axial parts of geosynclines terminates in the formation of a eutectic granitic magmatic solution. However, in case such solutions fail to develop while the accessions of the alkalic solutions continue, a miaskitic magmatic solution may arise, the parent of miaskites. Thus the crystallization of miaskites is contingent upon a progressive local metamorphism, in geologically rare and special environments in which the substratum acquires gradually a eutectoid, i.e. the miaskitic. The widely different series of intrusive alkalic rocks, from nephelinolites and alkalic gabbroids to plagioclase and corundum syenites, are the result of their reactions with their hosts, the mechanisms and the types of which depend upon the geological-structural conditions and other variables. – V. P. Sokoloff.