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The nature of the fault geometry within the mineable portions of the Twentymile Park Basin have made it
<br />difficult to accurately predict small displacement faults (< seam thickness of 10 feet) within a virgin mining
<br />district. Once two or more gate roads have been developed, the accuracy of prediction for the linear features
<br />• improves greatly. Several attempts have been made to use seismic methods to map the lateral fault traces well
<br />in advance of mining in the West and East Mining Districts. •Interpretation of the available seismic data
<br />(varying from older high resolution shots, recent 93 mini thumper and regional oil exploration lines) to date has
<br />not yielded an accurate tool for small offsets. The seismic, however, has greatly improved the overall mapping
<br />of larger structures.
<br />The 9 -Right fault that was encountered in July 1995 has seismic lines crossing perpendicular to its strike
<br />approximately 800 and ,1,400 feet to the south. None of the lines clearly defined a fault offset. The poor to
<br />moderate seismic results are partly the result of the small offsets (most less than 10 feet) and the rapid scissoring
<br />of the lateral faults. The 9 -Right fault is a good example of how the scissoring and splintering nature of the
<br />local faults (Exhibit 9B, 9 -Right Gateroad Faulting) can produce little or no vertical displacements along the
<br />lateral faults' strike. The faults encountered produced minor inflows of water, and the measured flow from the
<br />fault at XC -36 produced 10 gpm; the fault at XC47 produced 20 gpm. The measurement was obtained during
<br />July, 1995. The water temperature of the flow was 66 degrees and 70 degrees, respectively. A sample from
<br />each of the inflow points was obtained and sent to the laboratory for full -suite analysis. Only temperature was
<br />obtained and no field pH and EC measurements were made due to equipment problems.
<br />The lab results for the two samples, as presented in Exhibit 9B, are inconclusive and indicate the source of the
<br />water may be from the Wadge Overburden. Additional sampling will be conducted to try to verify the source of
<br />the water.
<br />Exploration holes drilled within the planned permit area are identified on Map 5, Surface Geology.
<br />Groundwater was encountered within the Twentymile Sandstone, the strata immediately above and including the
<br />Wadge Seam, and also within the Trout Creek Sandstone.
<br />. Complete chemical analyses of the Wadge Seam are presented in Exhibit 10, Geochemical Analysis of Wadge
<br />Seam. Data from the following drill holes are presented: 606-82 006- 82 -48, 006- 8248A, CH- 82 -58, CH-
<br />82-59, CH- 82 -28, CH- 82 -71, 021 -81 -022, 021 -81 -011, 021 -81 -020, 027 -82 -033, and CH- 82 -36. No significant
<br />amounts of acid - forming, toxic - forming, or alkalinity- producing materials have been identified with the coal
<br />seam. Lateral continuity and consistency of the Wadge Seam is good to excellent. Sample locations are
<br />illustrated on Map 12, Sample Locations.
<br />Lithologic characteristics, physical properties, and chemical analyses of the stratum immediately above (0 -10')
<br />and immediately below (0 -5') the coal seam are presented in Exhibit 11, Geochemical Analysis of Wadge Seam
<br />Overburden. Samples were analyzed for all soluble salts and toxic elements listed in the "Guidelines for the
<br />Collection of Baseline Water Quality and Overburden Geochemistry Data" (CMLRD, 1982). Data from the
<br />following drill holes are presented: CH- 82 -74c, CH- 82 -68, CH- 82 -64, CH- 82 -67, CH- 82 -59, CH- 82 -29, CH-
<br />82-14, and CH- 82 -54. Sample locations are illustrated on Map 12, Sample Location. Lithologic logs of these
<br />drill holes are included in Exhibit 12, Lithologic Core Logs.
<br />EMD (Panel 2 -Right through 6- Right, PR97 -04)
<br />The geology for the EMD is the same as that presented in Permit Revision No. 93 -03. However, Table 6B, 1997
<br />PR 97 -04 Federal Reserve Calculations for the Eastern and Northern Mining Districts, which is considered to be
<br />confidential, presents the federal reserves that will be mined in the remainder of the Eastern Mining District and
<br />the Northern Mining District. The detailed Wadge Seam structure is shown on Map 6, Wadge Seam Structures.
<br />The geochemical data presented for PR 93 -03 is used for this revision as well.
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<br />PR06 -07 2.04 -16 11/07/06
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