2015-08-18_PERMIT FILE - C1982056A (4)

Home Browse Search

The Wadge Seam ranges in thickness from 8.5 feet to 11.5 feet throughout most of the area to be mined, and reaches a maximum of 13.5 feet in the southwest portion (see Map 11, Wadge Seam Isopach). High heating values and volatile content place the Wadge Seam in a High Volatile, Group C, Bituminous Coal classification (see Exhibit 10, Geochemical Analysis of Wadge Seam). The lower one foot of the Wadge Seam is comprised of a high ash "bony coal" which is relatively uniform across the mine property This unit commonly forms a gradational contact with the underlying carbonaceous mud stone. No significant amounts of acid - forming, toxic - forming, or alkalinity- producing materials have been identified within the coal seam. Lateral continuity and consistency of the Wadge seam is good to excellent. Sample locations are illustrated on Map 12, Sample Locations, and lithologic logs of these drill holes are included in Exhibit 12, Lithologic Core Logs. Lithologic characteristics, physical properties, and chemical analyses of the stratum immediately above (0 -10') and immediately below (0 -5') the coal seam are presented in Table 20B, Geochemical Analysis of Roof Material - EMD, and Table 20c, Geochemical Analysis of Floor Material - EMD.. Samples were analyzed for all soluble salts and toxic elements listed in the "Guidelines for the Collection of Baseline Water Quality and Overburden Geochemistry Data" (CMLRD, 1982). Past experience has shown that out of seam dilution is the main contribution to unmarketable quality. Methods and equipment have been developed to limit the amount of out of seam dilution that occurs during longwall mining. Twentymile's Foidel Creek underground mine has invested in equipment to accurately measure inches of roof coal (gamma ray detector) and automatic monitor run of mine ash on the portal belt. The monitoring process, along with a detailed underground seam sampling and mapping program, allows mining equipment operators to try and selectively cut the coal horizon on the longwall face. Selective cutting leaves approximately 0.70 -foot of roof coal to control 0.25 to 0.65 -foot of soft friable shale in the immediate roof contact. Additional efforts are currently being made to control floor shale dilution by leaving 0.35 to 0.60 -foot of hard bony coal to keep the massive shearer from gouging or cutting floor rock. Directly below the Wadge Seam in the planned mine area is a persistent and laterally continuous layer of material composed of clay -sized particles called underclay. Beneath this underclay is a zone of alternating thick shales, claystones, siltstones, and intermittent lenticular sandstones. The shales are generally continuous and the sandstones discontinuous. Near the base of this zone of alternating beds is the Wolf Creek Seam. Within the planned mine area, the Wolf Creek Seam splits into four distinct benches separated by rock partings. The combined total seam thickness ranges from 7.5 to 14 feet, and the coal seams are continuous within discrete mining areas. The WC 1 Seam is the lowest of the benches, and ranges in thickness from 2 to 4 feet. The interburden between the WC 1 and WC2 seams ranges from 0.5 to 1.5 feet. The WC2 Seam ranges from 2 to 5 feet. The WC and WC2 benches will be mined over the entire WCR area. The interburden between the WC2 and WC3 ranges from 0.5 to 10 feet, but will not be mined once its thickness is greater than 3 feet. The WC3 Seam ranges from 2.5 to 4 feet. The interburden between WC3 and WC4 ranges from 0.5 feet to 4.5 feet, but will not be mined once its thickness is greater than 3 feet. The WC4 Seam ranges from 2 to 5 feet. Geologic information, including lithologic characteristics, physical properties, and chemical analyses of the stratum immediately above (0 -10') and immediately below (0 -5') the coal seam, and mine plan information for the Wolf Creek Seam are provided in Exhibit 53, Wolf Creek Reserve Geologic and Mine Plan Information. The geology of the Wolf Creek Coal Seam and Wadge /Wolf Creek Interburden is graphically illustrated by Maps EX53 -Ml through M5. The Wolf Creek Seam is separated from the underlying massive Trout Creek Sandstone by alternating beds consisting mostly of shale. Similar to the Twentymile Sandstone, the Trout Creek Sandstone is fine- grained and is a key marker bed. It defines the bottom of the Williams Fork Formation and the top of the Iles Formation. Immediately beneath the Trout Creek Sandstone is a massive marine shale. MINE FAULTS Technically, the fault encountered (July 1995) in the East Mining District's 9th Right gate road (Cross Section A - A'), would best be described as a very localized series of left lateral (sinistral) strike -slip faults that scissors to produce small displacements. Exhibit 9B, 9 Right Gate -road Faulting, presents a varied depiction of the faulting. TR13 -83 2.04 -15 11/03/14