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i <br />GEOLOGIC SETTING <br />The.Dorchestez Lolomine Lease holdings lie on the southwest <br />edge of the Canon City Embayment at rthe eastern foot of the Wet <br />Mountains. The lease straddles the axis of the Chandler Syncline <br />and lies east of the k'et Mountain Thrust. <br />S*_ratiRraphy <br />Trinidad Formation - The oldest geologic unit of significance <br />• <br />• <br />in the project area is the Trinidad sandstone. This unit is of Late <br />Cretaceous age, consists of a massive crossbedded yellow-brown <br />sandstone which grades downward into an argillaceous sandstone, and <br />ultimately into the underlying shale sequences. The Trinidad sandstone <br />does not outcrop on tie lease holdings but is important in that it <br />marks the bottom of the coal-bearing Vermejo formation. <br />Vermejo Formation - The Vermejo Formation, also of Late Cretaceous <br />Age, is the predominent coal-bearing unit in the Canyon City Coal Field. <br />In the project zrea the Vermejo is 800 to 1000 feet thick in full <br />section. Although coal beds in the Vermejo vary greatly in thickness <br />and lateral extent, eleven beds ranging from 1 to 11 feet in thickness <br />are recognized in the project area. <br />These beds are identified on the stratigraphic section, <br />Figure 2 The lithologic features <br />of the Vermejo vary from a coarse-grained cross-bedded sandstone <br />with a clay matrix to a fine-grained indurated mud or siltstone. The <br />coal seams can be correlated over distances of a mile or more but the <br />sandstone and shales are highly lenticular and intertoague. The <br />Vermejo outcrops or subcrops throughout most of the eastern 1/3 0'_ the <br />lease area. <br />Raton Formation - Overlying the Vermejo formation is the Raton <br />Formation. This massive yellow-gray sandstone is Late Cretaceous to <br />_ _ Z~ <br />T..-~_ _._..~ <br />