PERMFILE113883 - Laserfiche WebLink

Home Browse Search

Mayo and /Issoelales, LC • distances. The thickness of the Lower Coal Member averages 270 feet in the West Elk Mine area. The Lower Coal Member contains three recognized persistent, potentially mineable coal seams in its lower part. These are known as the A-, B-, and C-Seams (Figure 3). The A- Seam is not mineable in the West Elk Mine area. The B-Seam is the lowermost mineable coal seam in the mine area and is currently being mined by MMC. It is the thickest and most widespread coal seam in the mine area and, thus, comprises a large portion of the recoverable reserves. The total thickness of the B-Seam ranges from 1.5 to 26.5 feet across the lease area. The C-Seam is located above the B-seam and is not of economic importance in the lease area. The Lower Coal Member is almost always capped by massive sandstone units, which range in thickness from 20 to 225 feet. These sandstones, which appear similar in character to the • Rollins Sandstone but display much more variation in thickness, are informally designated as the "Upper and Lower Marine Sandstones". The top of the Lower Marine Sandstone marks the base of the Upper Coal Member. Upper Coal Member The Upper Coal Menmber contains approximately 220 feet of slmales, siltstones, sandstones and three persistent and potentially mineable coal seams recognized as the D-, E-, and F- Seams (Figure 3). In most locations, the D-Seam is not of economic importance. The E- Seam, which overlies the B-Seam by 170 to 300 feet, is the first coal seanm of economic importance above [he B-Seam in the mine lease area and is planned [o be mined by MCC. The interburden between the E-Seam and the overlying F-Seam ranges from 60 to 190 feet. • This interburden consists of shales, siltstones, thin coals, and generally lenticular sandstones. Characterization ofGroundwater Systems in the Vicinity of the West Elk Mine, Somerset, Colorado 29 January 1999 Page 13