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southeast part of the New Elk Mine workings. The dikes of the Raton Basin vary in thickness <br />from a few inches to more than 100 feet thick and are presumed to be intruded along fracture <br />systems. Sills also become more common to the east and north of the permit boundary. Magma <br />preferentially favors intrusion of weaker coal seams and in some areas of the Raton Basin the <br />coal reserves are totally obliterated by the sills. <br />2.04.6 (la) <br />Surface water in the New Elk Mine proposed permit area consists of the Middle Fork of <br />the Purgatoire River plus a number of ephemeral streams that drain a series of canyons on both <br />sides of the river. The North Fork of the Purgatoire River converges with the Middle Fork at the <br />extreme northeast edge of the proposed permit area. Flow and water quality information for the <br />Purgatoire River is presented in Section 2.04.7. The Right and Left Forks of Apache Canyon <br />dissect the central part of the proposed permit area whereas Ciruela Canyon traverses the <br />southeast corner of the proposed permit area. The drainage pattern is likely controlled primarily <br />by fractures and dip of the strata, however, igneous intrusions and erosion - resistant, thick, <br />cemented sandstone beds also assisted in the development of the geomorphic expressions and <br />drainage patterns of the region. <br />Regional groundwater flow in the basin is dependent largely on geologic structure and <br />topography. The regional flow is west to east and down dip. However, in the northern part of <br />the basin flow is radial away from the Spanish Peaks. Also, along the eastern margin of the <br />basin the strata dips to the west and groundwater flow is down -dip to the west. In the New Elk <br />proposed permit area the strata dips on average 2.2 degrees to the northeast (057) and fractures, <br />cleats and faults are oriented at approximately N80E (080). The orientation of the Middle Fork <br />of the Purgatoire River, Right Fork of the Apache, and the main Apache Canyon all align <br />conspicuously with the main fracture and fault orientations mapped in the New Elk Mine. This <br />supports the contention that many of the drainages are at least in part fracture controlled. Based <br />on these structural controls and topography, the groundwater flow in the permit area is W to E <br />with a slight northern component as water discharges into the Purgatoire River. <br />Three groundwater aquifers are identified by the Colorado Geological Survey (CGS) as <br />present in the Raton Basin above the base of the Vermejo Formation. These aquifers are: the <br />river valley alluvium, the Poison Canyon Aquifer, and the Raton - Vermejo Aquifer. The aquifer <br />of concern with regard to the mine workings is the Raton - Vermejo Aquifer as it underlies the <br />other two aquifers throughout the mine area and contains the coal seams planned for mining. <br />The CGS stated that water is transmitted by the sandstone layers, but thick coal seams also <br />contribute water. Transmissivities of the Raton - Vermejo Aquifer range from 0.02 to 79 ft /day <br />across the basin. <br />Fractures and joints tend to be better developed in sandstone then clay -rich rock types <br />such as siltstone and mudstone. Although seldom encountered, fractures observed in cores <br />during the 2010 New Elk drilling program occurred in sandstone and rarely in clay dominant <br />rock types. It is assumed that the fractures within clay -rich rocks are "healed" by their inherent <br />clay which may mobilize and seal fractures. Slickensided fractures were prolific in mudstone <br />units but these originate from sediment compaction and are extremely local in extent. The <br />TR56 <br />2.04 -11 <br />Revised 1 /10 /11 <br />Ea <br />