GENERAL35475

• Permit No: C1981021
• IBM Index Class Name: General Documents
• Doc Date: 3/1/1983
• Doc Name: PROPOSED DECISION AND FINDINGS OF COMPLIANCE
• Permit Index Doc Type: FINDINGS
• Media Type: D
• Archive: No

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is asymmetric about its axis. To the north, where the anticline plunges
northwest, the strike is approximately N45oW. To the south, the structure
begins to change strike as the crest of the anticline plunges almost due
south. Except near both noses, the anticline tends to be asymmetrical, with
the more steeply dipping limb to the east side.
At the rlarr and Canadian Strip mines, the sediments on the eastern flank are
near vertical or even overturned. In the area of the Bourg Mine, the strata
on the east limb of the McCallum Anticline dip as much as 41o to the
northeast. The Bourg Mine is flanked on the northeast by the Ballinger
Anticline. The axis of the Ballinger Anticline joins the axis of the McL"allum
Anticline in Section 21, T9N, R78W. The Ballinger Anticline plunges to the
northwest and strikes N35oW. The McCallum and Ballinger Anticlines form the
limbs of the Bourg Syncline. This syncline is asymmetric, strikes NSOoW and
plunges 4 to 8 degrees to the northwest. The entire Bourg Strip life-of-mine
plan area is within the Bourg Syncline.
The Ballinger Anticline structurallly separates the Bourg Syncline from the
Johnny rloore Syncline. The Johnny f4oore Syncline is an asymmetric syncline,
strikes N45°W, plunges to the southeast, and is flanked on the west by the
McCallwn Anticline.
Both the Marr Strip and the Canadian Strip coal mines are located on the
western limb of the Johnny I+ioore Syncline. The Canadian Strip is mining the
nose of the McCallum Anticline, while the Marr Strip is mining the east limb
of the fcCallum Nnticline.
The intense folding of the rock strata has produced numerous faults in the
general area. Faultiny increases at the noses of synclines and anticlines.
Stream channels have developed in several of the fault zones.
Two normal and one reverse fault exist within the Bourg permit area, at the
nose of the Bourg Syncline. Wyoming Fuel Coal Company has encountered 5
faults at the Canadian Strip Mine. This mine is at the nose of the fcCallum
Anticline. However, only 1 normal faults are known to exist in the entire
iwarr Strip, which is on the western limo of the McCallum Anticline. To date,
the only faults which produce pit inflows are the faults in the Canadian Strip.
North Park contains 15,000 feet of Triassic to Quaternary aged sedimentary
rocks. Late Cretaceous and Early Tertiary sediments account for almost all of
this total. Figure 4 is a generalized stratigraphic column of the North Park
Coal Field from the Kerr Coal Company permit application.
The Pierre shale is the oldest sedimentary strata exposed in the general area
of the mines. This formation is Late Cretaceous in age and composed of a
4,000 foot thickness of marine shales and minor amounts of siltstone and
sandstone beds. The upper Pierre shale contains a sandstone member which
forms the unconformable contact with the overlying Coalmont Formation. Due to
the marine origin of Pierre shale, the salinity is high in this stratum.
The coal seams of the North Park area lie in the Coalmont Formation of Early
Tertiary Age. The formation is composed of between 4,000-6,000 feet of