Where is the water? - A preliminary assessment of hydrogeologic characteristics of lithostratigraphic units near Espanola, north-central New Mexico
Daniel J. Koning, Scott Aby, and Steve Finch
For lithostratigraphic units near Española, potential hydrologic differences were assessed by estimating hydraulic conductivity (K) from transmissivity values. These transmissivity values were obtained from aquifer tests of wells (120-1500 ft deep) screened across one or more of these lithostratigraphic units, which include Quaternary valley-fill sediments and units in Santa Fe Group basin-fill sediments (late Oligocene to late Miocene). Depths of particular Santa Fe Group lithostratigraphic units vary with location due to faulting and west-tilting of the Española half-graben. Values of hydraulic conductivity ranged over two orders of magnitude, from 0.1 to 34 ft/day. The Quaternary valley fill has the highest hydraulic conductivity (0.7 to 34 ft/day, averaging 10 ft/day). The Chamita Formation and middle to upper Ojo Caliente Sandstone of the Tesuque Formation may provide the most productive water-bearing zones in the Santa Fe Group (with K ranging from 0.7 to 7.3 ft/day), followed by a combined unit consisting of interbedded Ojo Caliente Sandstone-Cejita Members and underlying lithosome B of the Pojoaque Member of the Tesuque Formation (K of 0.7 to 1.4 ft/day). In general, hydraulic conductivity for the remaining lithostratigraphic units, located in a lower stratigraphic position, range from 0.1 to 3 ft/day, with lithosome B of the Pojoaque and Skull Ridge Members being on the higher end of that range. Hydraulic conductivity generally decreases with stratigraphically lower units. Other influences on hydraulic conductivity and well yields include, but are not limited to, faults that act as barrier boundaries and secondary mineralization (cementation).
- Koning , Daniel J.; Aby, Scott; Finch, Steve, 2007, Where is the water? - A preliminary assessment of hydrogeologic characteristics of lithostratigraphic units near Espanola, north-central New Mexico, in: Geology of the Jemez Region II, Kues, Barry S.; Kelley, Shari A.; Lueth, Virgil W., New Mexico Geological Society, Guidebook, 58th Field Conference, pp. 475-484.