A geological-statistic analysis of commercial resources and the predictive coal-bearing potential of the fields of the South-Western coal region, the principal promising part of the Lviv-Volyn Coal Basin, has been carried out. Based on the detailed analysis and systematization of data from prospecting and exploratory-assessment works regarding the depth of occurrence and the thickness of coal seams, ash content, sulphur content and grade composition of coal, resources of the Tyagliv and Lyubelya fields has been re-evaluated. These characteristics have been studied by discrete intervals.
Re-evaluation of resources and their classification were carried out for every coal seam, the mine field, the field, and the coal-bearing region on the whole. In total, the analysis was performed for 24 coal seams. By the depth of occurrence of coal seams the majority of coal reserves at the Tyagliv and Lyubelya fields belong to the group of 600-900 m. The majority of predictive resources of coal within the Lyubelya field (6.6%) falls to the group of 900-1200 m. According to the thickness of coal seams, the most of the balance and overbalance reserves at the Tyagliv field is attributed to the groups of 0.61-0.80; 0.81-1.00 m, and at the Lyubelya field to the groups of 0.81-1.00; 1.01-1.20; 1,21-1.50 and over 1.5 m. Within the Lyubelya field, the predictive resources of coal are contained in the group of 0.81-1.00 m. According to the value of ash content, 50 % of balance and overbalance reserves of coal at the Tyagliv field are related to the groups of the medium-ash and ash coal. At the Lyubelya field, the most of coal reserves (66.4%) also corresponds to the group of medium-ash coal, and predictive resources — to the groups of medium-ash (43.1%) and ash (53.1%) coal. According to the content of the mass fraction of sulphur, at the Tyagliv field the balance and overbalance reserves of high-sulphur coal prevail, with the amount of sulphur, low-sulphur and medium-sulphur coal being at the equal ratios. At the Lyubelya field, high-sulphur and low-sulphur coal prevail almost at the equal ratios. Regarding predictive resources, the group of high-sulphur coal prevails within the field.
The coal seams within the Tyagliv and Lyubelya fields differ from analogous ones in the industrial part of the basin by the higher thickness and the area of distribution. The depth of occurrence of the seams increases for 15-300 m. Coal in the fields of the South-Western coal region has higher quality and the least ash content. According to brand composition of coal, the technologic groups of gas coal, gas-fat coal and fat coal (according to the Ukrainian classification) prevail at the Tyagliv field. It is proved that gas coal is suitable for coking. At the Lyubelya field, fat, coke-fat and coke coal prevail. Сoke coal comprises almost a half of the reserves. In the region, reserves and resources of coal are estimated to be over two billion tons, which exceeds in two times the residual reserves of the commercial part of the basin.
The analysis of the raw material base of the Tyagliv and Lyubelya fields, estimation of reserves and evaluation of coal resources have a great importance for developing and working-out of the feasibility study for their commercial development.
Preliminary report on the coal resources of the Dickenson area, Billings, Dunn, and Stark counties, North Dakota