## 2 Materials and Methods
### Analytical Work  
The basement rock samples were analyzed at the analytical center in the Sobolev Institute of Geology and Mineralogy of Siberian Branch of Russian Academy of Science. (SB RAS), to determine the content of the petrogenic components (i.e., SiO\({}_{2}\), Al\({}_{2}\)O\({}_{3}\), TiO\({}_{2}\), etc.) using X-ray fluorescence (XRF) analysis. The samples for analysis were dried at 105 \({}^{\circ}\)C for 1 h, heated to 1000 \({}^{\circ}\)C for 2.5 h, and then mixed with a flux (66.67% lithium tetraborate, 32.83% lithium metaborate, and 0.5% lithium bromide) in a ratio of 1:9; the total weight of the mixture was 5 g. The mixture was then melted in platinum crucibles in a Lifumat-2,0-Ox induction furnace (Linn High Therm GmbH, Eschenfelden, Germany). The glasses obtained in this way were analyzed using an ARL-9900-XP XRF spectrometer (Thermo Fisher Scientific, Waltham, MA, USA). The determination error does not exceed that specified for the second category of accuracy according to the OST 41-08-212-82 standard.  
Mass fractions of the microelements in the samples were determined by inductively coupled plasma mass spectrometry (ICP-MS) at the Plasma Chemical Analytical Center (Tomsk) according to the method for measuring the mass fractions of elements in rocks by ICP-MS \(N\) 002-KhMS-2009, FR.1.31.2010.06997. The determination error did not exceed 7%.  
The mineral compositions of the heavy and light fractions of the 47 rock samples were determined in the analytical center in the Sobolev Institute of Geology and Mineralogy of SB RAS using X-ray diffraction analysis (XRD) on a DRON-3 X-ray diffractometer. A 10 g weighed portion of the 0.1-0.25 mm fraction was separated from the dust fraction in water; the heavy fraction was then isolated in bromoform for each sample. X-ray phase analysis was then carried out on the prepared heavy fraction.  
In addition, vibrational infrared (IR) spectra were recorded for the heavy fraction of eight samples. This technique records the short-range order of the structural organization of substances. IR spectra were recorded in the range 400-4000 cm\({}^{-1}\) on a Brucker VERTEX 70 FT IR spectrometer. Samples were prepared for this procedure by mixing with KBr and pressing into tablets.  
For the water samples collected from the tailings pond, the pH, redox potential (Eh), and electrical conductivity were determined in situ using potentiometric and conductor-metric methods. The pH and Eh values were measured using an Expert-001-3.0.1 ionomer. The limits of the basic absolute error of the analyzer are \(\pm\)0.03 units for pH and \(\pm\)10 mV for Eh. The specific electrical conductivity (EC) was measured using the conductometric method on a Cond 315i device with a tetraco325-3 sensor. The measurement range was 0-500 mS/cm and the measurement error was \(\pm\)1%.  
Under laboratory conditions, 500 mL of each sample were filtered through a \"blue ribbon\" filter and the concentrations of Cl\({}^{-}\), SO\({}_{4}\)\({}^{2-}\), NO\({}_{3}\)\({}^{-}\), NO\({}_{2}\)\({}^{-}\), and NH\({}_{4}\)\({}^{+}\) were determined in the filtrate via capillary electrophoresis. The cation contents (i.e., Ca\({}^{2+}\), Mg\({}^{2+}\), K\({}^{+}\), and Na\({}^{+}\)) and trace elements were determined using the ICP-MS method at the Plasma Chemical Analytical Center (Tomsk). The determination error did not exceed 5%.