Transformation Of Amphibolites And Fractal Dimension Of Migmatites Of The Belomorian Complex As Evidence For Synchronism And Periodicity Of Shear Deformation and Migmatization

摘要

Migmatization is characteristic of regional shear zones in ancient metamorphic complexes. This process is accompanied by ultrametamorphism, granitization, and growth of granitic domes. Migmatites were studied comprehensively by many researchers because of their important implications for the formation of the Earthis sialic crust. Nevertheless, the mechanism of migmatization has remained a matter of debate. Investigation of structural and compositional transformation of amphibolites in the Khetolambina sequence of the Belomorian Complex by methods of petrography and fractal analysis provided insight into the mechanism of this process, allowed us to ascertain paragenetic relations between migmatization and shear deformations in the absence of granitic plutons, and revealed the general trend and discontinuous character of migmatization. Since migmatization is always accompanied by metasomatism, the term migmatite is applied in this communication to products of both partial melting and attending metasomatism.