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• aquifers. Springs and seepage areas are also likely receptors <br />of gravity flow. <br />Hydrologic Characteristics <br />No data are available on the local hydrologic characteristics <br />of these aquifers. However, reported small yield in wells indicates <br />that permeabilities and storage is low. Specific yield is the amount <br />of water available for release from storage by gravity drainage. <br />If the grain size and composition of the aquifers is known, then <br />generalized conclusions can be drawn from the literature. Typically, <br />specific yield values for water table aquifers composed of fine silts <br />and clays are less than 108. The Trinidad sandstone and Vermejo <br />Formation fall into this category. Gravels and coarse sands have <br />values greater than 208. Sands of the Raton Formation would most <br />likely fall between 10 and 208. <br />• Generalization can also be made of porosity values. Fine <br />sands, silts and clays typical of the Vermejo will range from 15 <br />to 308 porosity. The cleaner sands of the Raton Formation should <br />be approximately 20 to 308 while those of the Trinidad fall below <br />208. <br />Formation coefficient of permeability is estimated to be low <br />in all three units. All are probibly less than one darcy. Per- <br />meability in the Vermejo may be as low as 100-500 millidarcies in <br />the sands and siltstone. In addition, Vermejo coal seams may have <br />secondary permeabilities due to fracturing and channeling. <br /> <br />FISHER. HARDEN 8 FISHER <br />126 <br />