Summary:
The lifeblood of the Khondiza mining complex begins with the Khondiza mine. It is located in the central part of the Surkhantog mountains in the Hisar range, in the Sariosia region, 54 km from the district center. The Khondiza mine has an area of 40 km2, irregularly extending in the north and north-west directions.
Geographically, the area of the mine is characterized by a distinct mountainous terrain. The ore field is surrounded by the Hisar mountain range, the highest point of which is 3075.2 m in the north, and in the area of the central part from 1300 m (Khondiza river valley) to 1800 m. It is located 60 km away from Saryosi railway station.
In the mining area, rocks with three structural layers lie flat.
- lower: at about 280 m, the Khondiza Range of rocks is represented by Precambrian metamorphic rocks, crystalline shales, two-mica gneisses and gneissic granites;
- medium: characterized by volcanogenic-sedimentary rocks of the Carboniferous period;
- upper layer: in the sediments of the lower and middle layers, Jurassic terrigenous sedimentary rocks are formed in the form of a shell.
The main ore deposits combine a series of layered ore bodies with solid ore alternating with lenticular and vein-granular zones. In general, it stretches in the sublatitude. The decline is relatively steep, 25-300 in the south and 45-600 in the north.
The greatest strength is characteristic of the inclined and flexural bending sections, and it is sharply expanded on the slopes. The deposit is bounded from above and below by the terrigenous-carbonate-pyroclastic pack on the thrust side and the volcanogenic pack on the overhang side by the contact with the horizon rocks. Within the bedrock and ore layers, there are folds with a brachiform structure. The peculiarity of the ores is their fine-grained structure with a quantitative ratio of chalcopyrite to galena, sphalerite and pyrite of 0.5:1:3:4.
In general, the ore bodies are located in a section of several hypsometric levels, separated by non-ore layers of volcaniclastic rocks, 10 to 30 m thick. No 3, No 2, No 4, No 6 and No 8 are the largest bodies. Small lenticular bodies No 5, No 7 and No 9 are placed in the intervals between them.
Ore body No. 3 is one of the main deposits in the mine. It has more than 80% of all explored mineral reserves. It is 600 m in length, 780 m in roll, and 14 m in average real capacity. The ore body is not completely contoured to the north and east.
The position of ore body No. 3 is determined by rhyolite-porphyry tuffs of rhyolite-dacite porphyry of the lower volcanogenic horizon.
Other ore bodies are calculated as percentages of reserves: No 4-5%; No 5-5.7%; No 6-4.7%; No 8-2%; No 7.9 to 0.5%; No 5-0.3%.
The highest strengths of ore bodies No. 3 (18-21.6 m) adjusted to the central part of the body are between the +1300 and +1000 m marks and adjusted to the slope of the flexure. Below the +1000 m mark, the average power decreases to 6-8 m.
Mining ores make up the main part of the deposits and are divided into vein-particle and solid massive types and form small ribbon-shaped accumulations within the main mass of ores. A special feature of mining ores is the small content of barite (1-1.5%). Elements of mixtures are found both in the main sulfides (sphalerite, galena, pyrite, chalcopyrite) and as independent materials.
Silver is isomorphically bound to major sulfides to form argentite, freybergite, prustite, and other independent minerals. In the ores, gold is found as a fine dispersion and also as admixture in the form of galena, chalcopyrite, pyrite and possibly telluride. Cadmium occurs as an admixture in sphalerite ores. The main minerals in the host rocks are quartz, plagioclase, potassium feldspar, muscovite and biotite.
Thus, the chemical composition of ore massifs and pile rocks is drastically different. Mineral sulphides are not characteristic of aggregates or loose rocks. This makes it possible to characterize them as inert and non-aggressive rocks when exposed.