Journal articleOpen access
On the peculiarities of changes in hydrogeological conditions during the development of the Yoshlik field
Об особенностях изменения гидрогеологических условий при разработке месторождения Ёшлик
- Almalyk branch of Tashkent State Technical University, Almalyk, Uzbekistan
Highlights
- Depth to groundwater before mining: 25–38 m; regional fracturing reaches about 100 m.
- Filtration coefficient: 0.004 m/day (fracture groundwater), 0.127 m/day (fracture–vein water), 0.065 m/day (deposit as a whole).
- Fracture water: dry residue 300–1,040 mg/L on average, some springs 2,000 mg/L and more; hardness 5.4–13.2 mg-eq/L; pH 6.2–7.6.
- Expected inflow to the pit: 32–44 L/s (highest yearly mean), 63–75 L/s (highest monthly mean), 29–41 L/s (long-term mean).
Abstract
The article deals with the formation, filtration, movement and conditions of groundwater occurrence in the field. The factors of water influx leading to the accumulation of groundwater during the development of the field, the nature of the watering of Paleozoic deposits along all sides and ledges are given. The study found that the regime of water occurrence is characterized by seasonal changes in atmospheric precipitation. The results of chemical analyzes of groundwater are presented, a forecast is made about possible changes in the chemical composition of groundwater during the development of the deposit. Information is given on the conservation of heads, leading to a decrease in the stability of benches, sides and to the moistening of a mineral, a decrease in its quality characteristics.
English abstract from the paper. The authors’ abstract, reproduced under CC BY-NC 4.0.
In plain English
The Yoshlik deposit lies in the basin of the Almalyksay, a left tributary of the Akhangaran, with the Kalmakyr deposit to the east and the Karamazar mountains to the south. Intrusive rocks cover more than 55% of its area, volcanic rocks about 40% and layered terrigenous and carbonate rocks less than 5%. Before mining, groundwater lay 25–38 m below ground and flowed north and north-west with the slope. In 1984 the Almalyksay was dammed upstream and led away through a 600 m tunnel.
The authors distinguish a water-bearing layer in modern alluvium, groundwater in open fractures of five groups of Palaeozoic rocks, including hydrothermally altered Middle Carboniferous rocks, and fracture–vein water along faults. Fracture groundwater is fed only by precipitation; its level rises from late February, peaks in late May or early June and is lowest in November. Its mineralisation rises from 220 to 800–900 mg/L between the recharge and discharge areas; its dry residue averages 300–1,040 mg/L over the year, with some springs at 2,000 mg/L and more, its hardness is 5.4–13.2 mg-eq/L and its pH 6.2–7.6. Fracture–vein water flows at 9.3–12.5 L/s through the year, and springs where valleys cut the faults give 0.5–1 L/s, rarely 10–17 L/s. Water in the alluvium of the Almalyksay is bicarbonate–calcium water with 0.16–0.28 g/L of dry residue.
The authors judge the hydrogeological conditions simple: the water-bearing rocks filter water poorly, regional faults add little water to the pit, and groundwater will not hold back mining. Average filtration coefficients are 0.004 m/day for fracture groundwater, 0.127 m/day for fracture–vein water and 0.065 m/day for the deposit as a whole. They expect inflow to grow by 0.23 L/s for each metre the pit deepens, to 31.7 L/s after another 75 m.
How to cite
Yu. P. Isomatov and B. A. Gaibnazarov (2021). On the peculiarities of changes in hydrogeological conditions during the development of the Yoshlik field. International Journal of Advanced Technology and Natural Sciences, 2(1), 4–8. https://sciencealgorithm.uz/?portfolio=%D0%BE%D0%B1-%D0%BE%D1%81%D0%BE%D0%B1%D0%B5%D0%BD%D0%BD%D0%BE%D1%81%D1%82%D1%8F%D1%85-%D0%B8%D0%B7%D0%BC%D0%B5%D0%BD%D0%B5%D0%BD%D0%B8%D1%8F-%D0%B3%D0%B8%D0%B4%D1%80%D0%BE%D0%B3%D0%B5%D0%BE%D0%BB