Судовиков, Н. Г. Материалы по петрологии Западного Беломорья : (гранитизация пород Беломорья) / Н. Г. Судовиков ; Главное геологическое управление. - Ленинград ; Москва : ГОНТИ, Редакция горно-топливной и геолого-развед. литературы, 1939 (Ленинград). - 86, [1] с., [1] л. табл., [1] л. карт. : ил., карты, схемы. - (Труды / Ленинградское геологическое управление ; вып. 19).

granitisation in that aspect, in which it is presented by data from the Wliite- Sea region. 1. Basing on the petrographic composition and partly on the distribution of disthene and garnet gn eisses, the writer con clud es that these rocks compose peripheral zon es of areals of granitisation. The composition and texture of these rocks always reflect the mobility of quartz solutions in this zon es which is seen here in the widespread p rocesses of quartz metasomatism. Certain amphibolites, for which secondary development of quartz is particularly characteristic, also b e lo n g to this zone. Zon es of quartz metasomatism mark on ly the upper horizons of spheres of granitisation. The well preserved oldest north-east strike of rocks is charact­ eristic of these zones, and points to the absence of fundamental changes during subsequent processes of granitisation. The action of quartz metasomatism in most cases did not affect the basic structure of the rock here. In deeper horizons rocks of this zone alternate with g n eisses carrying traces of feldspar metas­ omatism. 2. The zone of feldspar metasomatism is the most extensive and in rocks of a basic composition begins with the formation of plagioclase. Potassium metasomatism is established particularly well, and begins with the penetration of potassium — containing solutions into intergranular interstices of gn eisse s and the formation of microcline or orthoclase in them. In the same way under conditions of very intensive granitisation uniform masses of granites form in the White-Sea region, presenting an extreme degree of migmatisation. Form ing under conditions of successive metasomatism these rocks hardly ever show traces of magmatic texture. 3. Within the limits of every comp lex of rocks series of rocks may be distinguished characterizing different degrees of granitisation, which depend on general regional conditions as well as on particular conditions of penetration of granitising solutions. 4. P rocesses of metasomatism together with granitisation p rocesses som e ­ times take place under conditions of quiet environment almost without disturbing the original structure of the ancient masses. 5. Inspite of that that processes of granitisation arc localised, areals are limited, their mapping presents great difficulties due to the overlapping of ph enomena b elon gin g to different epochs of granitisation. Reliable methods of studying complex conditions of overlapping phenomena must be the study of structure with a complete analysis of mo vem ents, study of zon ing and a careful study of all petrographic details. 6. Traces of quartz metasomatism were established in almost all granifised rocks and everywhere they are the latest, affirming that quartz metasomatism does not characterize only the beginning of granitisation but also ends it. In connection with the above-men tion ed con clusion s a possibility of wider generalisations arises, from which however, the writer declines not h av ing at the present sufficient material on analysis of structure. The writer b elieves that a close study of such a region as the White-Sea region can bring us nearer to the decision of general problems of petrology which are not only of a g rea t theoretical but also a great practical significance