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PAGE S properties in Coal Canyon). The hydrological characteristics of the Cameo bed overburden in both mines has presumably been adequately discussed in those submissions apropos to the Roadside Mine. The Cameo B coal bed as mined from the Roadside Mine can be described generally as between 6 and 10 ft in thickness, containing numerous thin bony (high-ash) bands but also containing unusually thick, persistent bands of ]ow-ash vitrain. Fusain, or mineral chazcoal, is also common. The coal usually moderately to well cleated, although cleats tend to disappear in layers high in fusain. Principal cleat direction is approximately north-northeast -south-southwest (N20E). As previously noted the floor consists of the Rollins Sandstone in places, although the coal is usually separated from the sandstone by at least a few feet ofthin-bedded to laminated carbonaceous shaly mudstone to siltstone, which usually contains at least some wind-blown sand. This shale material creates an e$~ctive seal between the sandstone and the coal, although it is occasionally broken by laterally- persistent regional fractures, which break the«ie+~as well. The coal is overlain by thinly laminated fine-grained sandstone and coal to coaly mudstone, 0 to 18 inches thick, and then by a massive silty mud- to sandy siltstone; the latter forms good to moderately good roof, while the laminated material frequently falls during mining or slacks off afterward. Pyrite nodules and lenses, and broad-scale ripple marks and ripple marks commonly occur at the boundary between the coal and the roof. The roof is broken occasionally by fractwes of varying persistence that strike roughly northeast- southwest. Fractures are usually single breaks that die out in a few feet in either direction, to be replaced with another an inch or two away. Several such breaks may parallel each other for some • distance. These fractures are usually damp and may occasionally drip water for some time after mining has passed. None aze major water sources. Sandstone dikes occur frequently in the Roadside North Portal workings, less so in Roadside South. Petrographically the dikes are indistinguishable from the underlying Rollins Sandstone, from which they originated. Distortions in coal bedding adjacent to the dikes, fragments of coal in the sandstone, in places to the extent of forming a breccia, and common thinning of the dikes from the bottom up are convincing evidence that the sand was intruded into the coal-forming materials from below, while both were in asemi-consolidated condition (some coalification had to have taken place for coherent fragments to have been incorporated in the sand). Occasional orphaned chunks of sandstone, offset dikes, and other such features resulted from bedding movement in the coal after intrusion. When encountered these dikes are usually dry and hard. They frequently absorb some moisture, mostly from sprays on the mining machines. Clays in the sand matrix hold this moisture and, depending on the type of rock dust being used, the dikes may then produce a damp stain on the ribs (sides) of mine openings. Dikes are not known to produce water except in those few locations where they coincide with fractures as discussed above. Sandstones in immediate proximity to the Cameo coal beds are thin, lenticular, and very similar in content to the underlying Rollins, the primary difference being a higher sedimentary lithic fragment content (Pitman, 1989, p. G 19}. Porosity and permeability are more variable than the Rollins but remain low. The mudstones and siltstones in the zone are dense, mostlythin-bedded to massive, • virtually impermeable (although they frequently disintegrate on exposure to air and moisture), and form sealing layers. s