Shallow geophysical study of the Grapevine Canyon area, eastern Tularosa Basin: implications for groundwater resources
— Wayne L. Belzer, Kate C. Miller, and Steven Harder

For the residents of the Tularosa Basin, fresh water is a scarce resource. Water is obtained either from stream diversions in the mountains or from rapidly depleting aquifers in the basin. Here we report on results from geophysical surveys undertaken in 1997 to help locate new potable groundwater supplies in the eastern Tularosa Basin, near Grapevine Canyon. This area is considered a good candidate for the location of potable water because groundwater is thought to be diverted into the basin along fault systems and surface canyons of the Sacramento Mountains during snowmelt in the winter and during rainfall in the summer. The geophysical surveys included a 2-km-long seismic profile, and nearly 600 gravity readings, taken primarily along three east-west profiles. Interpretation of the data suggests that the bedrock contact slopes northward from depths of 250 to as much as 1000m and that a previously unrecognized graben system occurs in the subsurface immediately adjacent to the Sacramento Uplift. Basin fill within the graben system is probably comprised primarily of fine-grained lacustrine deposits. The presence of these deposits reduces the likelihood of finding permeable zones with freshwater, but may be indicative of ongoing tectonic uplift of the Sacramento Mountains.