PERMFILE130306

• Permit No: C1981014
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: EXHIBIT 23 SUBSIDENCE INFORMATION
• Media Type: D
• Archive: No

•
I
r 1

2.1
2.0 SUBSIDENCE SURVEY (RULE 2.05.6(6)(e))
The maximum subsidence (S) and subsidence profile, as a
result of mining, is influenced by both the mining system and the
geology of the site. The lithology of the formation above a coal
seam together with the bed thicknesses, bedding cross-joint
frequency and faults all control subsidence. The general
description of the mine plan, geology of the site and subsidence
predictions are included in the following sections.
2.2 Mine Plan (RULE 2.05.6 (6) (e) (i) (A) )
The Dorchester No. 1 Mine is designed to utilize continuous
miners for development and retreat. The typical mining section
would consist of a continuous miner, two shuttle cars, a
feeder/breaker, a section power center, a roof bolting machine
and auxiliary fans.
The mining operations will utilize a room and pillar method
of extraction. This extraction will remove 38-53 percent of the
total reserves during the development of each mining panel. The
development stage will be followed by the retreat phase. The
retreat phase will remove an additional 40-44 percent of the
remaining reserves. The final extraction percent in most
sections will vary between 75 and 93 percent.
The mine plan, shoxing panel locations, mine entries and
expected dates of development and retreat phases, is presented in
Appendix A.
2.3 ~oloav (RULE 2.05.6 (6) (e) (i) (B))
The majority of the Dorchester No. 1 mine lies within the
northeast limb of a structural feature known as the Chandler
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