2009-08-25_PERMIT FILE - C1991078A

• Permit No: C1991078A
• IBM Index Class Name: Permit File
• Doc Date: 8/25/2009
• Section_Exhibit Name: 2.04 Environmental Resources
• Media Type: D
• Archive: Yes

2.04.6(21
• Lithology Description
(a) Five coal seams have been identified in the hori-
zon to be mined in the permit area. They are identified, in
descending order, as the Upper Dakota-1, UD-1, Lower Dakota-1,
LD-1, Lower Dakota-2, LD-2, Lower Dakota-3, LD-3 and Lower Dako-
ta-4, LD-4. The LD-2 and LD-3 Seams are of a mineable thickness
throughout the permit area. In the southern portion of the
permit area the LD-4 Seam is of a mineable thickness. The thick-
ness of the LD-2 Seam ranges from 1.6 to 3.5 feet thick with an
average thickness throughout the permit area of 2.5 feet with
depths from the surface to the top of the seam ranging from 7.2
to 28.7 feet. The LD-3 Seam averages 1.6 feet thick and ranges
from 0.8 to 2.9 feet thick. The LD-4 Seam ranges from 1.2 to 3.1
feet in thickness with an average of 2.1 feet.
The splits between coal seams consist primarily of
thin, lenticular, dark, carbonaceous shales. The split between
the LD-2 and LD-3 Seam ranges in thickness from 0.3 to 1.0 feet
,with an average of 0.6 feet thick throughout the permit area.
The split between the LD-3 and LD-4 Seam averages a thickness of
1.1 feet and ranges from 0.7 to 1.7 feet in thickness. AnY
splits within the seams of thickness less than 0.3 feet will be
taken with the coal during the mining operation.
There are two rider coal seams identified in the
• permit area and are referred to as the UD-1 and LD-1 seams.
Neither rider seam is consistent in extent within the permit area
and therefore not considered mineable. Where identifiable, the
UD-1 and LD-1 rider seams are as much as 1.2 and 2.0 feet in
thickness, respectfully. Rider seam LD-1 overlies an average 0.8
feet thick dark shale layer. The stratum which overlies the LD-1
rider seam and underlies the UD-1 rider seam consists of an
average 7.0 feet thick gray shale. The stratum overlying the UD-
1 rider seam consists of a soft, .yellowish, fine-grained sand-
stone that varies in thickness from 2.8 to 19.0 feet thick from
the top of UD-1 to the ground surface.
The stratum immediate below the lowest mineable
coal seam consists of a soft, gray to blue shale with spars
shaley siltstone lenses. This strata is generally 26 feet thick
throughout the permit area. Below this strata there are four
coal seams that are not considered mineable within the permit
area. These coal seams are referred to as Naturita Seams 1
through 4 in descending order.
• 2.04-7