New Mexico Geological Society Annual Spring Meeting — Abstracts

Water well drillers' logs (after accurately locating the wells with GPS equipment) were used to map the groundwater table and subsurface structure. Basalt and clastic interbeds allow driller's ample descriptions to be correlated from the Rio Grande Gorge to the town of Taos.

The main feature herein, called the Airport arch, is a northeast-trend uplift with surface expression, Nurnerous nonnal faults have been mapped, especially on the east flank of the arch. Four north-trending faults seen at the surface in Los Cordovas can be traced northward and southward in the subsurface. Other faults have been mapped on the Hondo Mesa and BluebeITY Hill. Faults appear to interfere with the lateral flow of groundwater westerly toward the Rio Grande Gorge.

Groundwater recharge from streams near the mountain front shows seasonal drops in water level and an overall drop during the last eight years of drought. Communities near the mountain front have seen water levels drop in response to the drought, while wells farther out in the valley have seen little effect.