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).

zoisite gn eisses and schists. The writer com es to the conclusion that quartz metasomatism is characteristic of disthene and garnetiferous gn eisses, whereas for the biotite and amphibole gn e isses feldspar, metasomatism is characteristic. The same features of quartz metasomatism have been noted by the writer for the little distributed, peculiar zoisite g n eisses and schists, which, the writer supposes, were formed by the metamorphisin of calcareous sediments under conditions of pneumatolysis. In the chapter “Migmatites” the chief features of the White-Sea migmatites are characterized. Here is also noted the presence of extremely gradual changes between diverse migmatites and granites, which indicates, as the writer b e­ lieves, a common origin of these rocks. In this chapter an attempt was also made on the data of a few chemical analyses (Tab. I & II) to characterize the interrelations between gn eisse s and granites. The curve, given on fig. 14, is on ly a general expression of the process of granitisation, which g o e s in the direction of a decrease of the excess alumina and an increase of alkalies to granites. In the description of amphibolites the follow ing are distinguished by the writer: 1) amphibolite with hornblende, presenting partly altered basic rocks and partly metamorphosed calcareous sediments, 2) gedrite amphibolites — probably altered sedimentaries, and 3) amphibolites containing pargasitic and tremolitic amphiboles, also probably altered sediments. Characteristic of amphibolites of the first group are phenomena of su cces­ sive metasomatism, which leads to the transformation of monomineral amph ibol­ ites into amphibole gneisses. In amphibolites of this group new ly formed textures with crystallization similar to magmatic were noted by the writer (see photo № 5, 6, 7). S tudying the forms oi amphibolite bodies the writer came to the c o n c lu s­ ion about the occurrence of the amphibolite bodies as representing disintegrat­ ed bodies of basic rocks altered into amphibolites. In the process of disin­ tegration the writer notes a similarity to boudinage. In a detailed description of contacts of basic rocks with g n eisses and mig­ matites the writer characterizes phenomena of granitisation of basic rocks, points out the local character of processes of migmatisation, g iv es facts of stratigraphic significance and considers hybridisation phenomena. In the chapter „Basic R o ck s“ metamorphic phenomena are chiefly analyzed and the shape of intrusive bodies of basic rocks is considered. In the chapter “Granodiorite and Related Rocks of P on g om Island” the writer g ives a petrological characteristic. Dwelling on problems of origin the writer points to the probability of their formation by deet-seated granitisation from more basic rocks. Phenomena of anatexis are characteristic of the origin of the more acid representatives of the diverse and complex group of gratiodi- orites. These rocks formed probably under conditions of very high temperat­ ures and in a relatively quiet environment. In the chapter “Granites” after considering som e characteristic features of ih ese rocks and analyzing criteria for distinguishing them from g n e isses, the writer comes to the conclusion that the majority of the granites oi the White- Sea coast region were formed by deep-seated granitisation of rocks of the g n e is s complex. In the chapter „The sequence of rocks of Varbar Luda Island" the writer characterizes the stratigraphic relations of granites. Here is noted also the significant pari played by succesive metasomatic processes in the formation of granites. In the chapter “Pegmatites” after a brief petrographic chatacteristic and description of the shap e of pegmatite bodies the writer considers their origin, touching upon bodies chiefly industrial importance. The writer believes that on the coast region o f the White-Sea the more w idely distributed are pegmatites 85