## 2 Materials and Methods
### Collection of Rock Samples and Petrographic Analysis  
An obligatory condition for the implementation of any microstructural analysis technique is the collection of spatially oriented samples, for which spatial fixation must be strictly observed throughout the entire duration of their processing [13; 22; 24; 25; 26; 27; 28; 29; 30; 31]. Samples for petrographic and STMA studies were collected mainly in the outfall parts of the Sarma river. Rocky outcrops contain dislocated series of rocks of the Neo-Proterozoic that had undergone multistage physical and chemical transformations while being exposed to stress metamorphism. It is specific for amphibolite and greenshale facies of regional metamorphism.  
The collected and analyzed samples of rocks are represented by numerous varieties of predominantly metamorphic and igneous rocks, as well as their metasomatically altered varieties. Shales (55-1, 55-3, 56-1, 57-1, 60-3, 81-3, 81-4, 81-5), greissose granite (58-1, 59-1, 59-2, 60-1), plagiogranites (55-3, 55-4), amphibolites (60-2) and gabbro (61-5), varied in mineral composition, were distinguished (Table 1). The studied rock samples are classified as mylonites (81-4), blastomylonites (55-1, 55-3, 81-3, 81-5), cataclasites (55-4, 60-2, 60-3), blastocataclasites (56-1, 57-1, 61-5) and host rocks (58-1, 59-1, 59-2, 60-1), which were not subjected to intensive deformations. Among other characteristics, the type of deformation (brittle or ductile) was assessed, and metamorphic and metasomatic changes were marked.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Sample** & **Petrographic Type** & **Tectonic Type** & **Deformation Mode** & **Main Minerals * and Proportions (\%)** & **Metamorphic and Metasomatic Transformations** \\ \hline
55-1 &
\begin{tabular}{c} Quartz-Sericite- \\ Chlorite \\ shale \\ \end{tabular} & Blastomylonite & Brittle & Q(60), Fsp(20), Src(10), Cl(5) & Complete recrystallization of quartz; sericle is formed by plagioclase; actinolite is chloritized \\
55-3 &
\begin{tabular}{c} Contact rock: \\ Quartz-Actinolite- \\ Chlorite \\ shale- \\ \end{tabular} & Blastomylonite & Brittle and ductile & Fsp(60), Q(30), Cl(5), Ac(3) & Partial recrystallization of quartz; sericle is formed by plagioclase; actinolite is chloritized \\
55-4 &
\begin{tabular}{c} Plagiogranite \\ \end{tabular} & Mylonite & Brittle & Q(60), Fsp(30), Ac(5), Cl(3), Src(2) & Partial recrystallization of quartz; sericle is formed by plagioclase \\
56-1 &
\begin{tabular}{c} Plagiamphibo- \\ bile \\ shale \\ \end{tabular} & Mylonite & Brittle & Q(50), Fsp(40), Src(5), Cl(3), Ac(2) & Partial recrystallization of quartz; sericle is formed by plagioclase; actinolite is chloritized \\
57-1 &
\begin{tabular}{c} Chlorite-Sericite- \\ Plagioaturztite \\ shale \\ \end{tabular} & Blastocataclasite & Brittle & Q(50), Fsp(30), Src(15), Cl(5), Ac(1) & Partial recrystallization of quartz; sericle is formed by plagioclase; actinolite is chloritized \\
58-1 &
\begin{tabular}{c} Leucratic \\ geneissose granite \\ \end{tabular} & Host rock & Brittle & Q(55), Fsp(35), Mu(2), Bt(2) Am(1) & Quartz is slightly granular \\
59-1 &
\begin{tabular}{c} Leucratic \\ geneissose granite \\ \end{tabular} & Host rock & Brittle & Q(50), Fsp(35), Mu(5), Bt(4) Am(1) & Quartz is slightly granular \\
59-2 &
\begin{tabular}{c} Leucratic \\ geneissose granite \\ \end{tabular} & Host rock & Brittle & Q(50), Fsp(35), Quartz is slightly granulared; about 10\% potassium feldspar \\ \hline \hline \end{tabular}
\end{table}
Table 1: Petrographic description of rock samples.