New Mexico Geological Society Annual Spring Meeting — Abstracts

Four sequential aquifer tests were conducted in four new replacement wells in the Guaje well field in 1998. One of these tests was repeated in 2005. Each test consisted of a pumping phase and a recovery phase that totaled about four days. These tests reveal horizontal propagation of drawdown in the regional aquifer for varying distances up to about 4,700 ft from each pumping well. Dynamic spinner logs reveal a complex, highly stratified aquifer that varies in effective thickness from about 435 ft in the east to about 325 ft in the west. In the east, most of the higher yielding zones are located above Miocene basalt flows that separate medium-grained fluvial deposits from lower yielding fine-grained sands and silts in the Tesuque Formation of the Santa Fe Group. In the west, these high-yielding units are interbedded with the basalts. The observed westward thinning of the regional aquifer reflects eastern and northern source areas for these piedmont-slope deposits. The transmissivity of the highyielding zone varies from about 2,900 ft² /day near well G-2a (east), to about 1,650 ft² /day at well G-4a, and about 700 ft² /day at well G-5a (west). The storage coefficient averages about 0.00097. Barrier boundary effects were also observed and represent a complex response to pumping from an aquifer that may be simultaneously offset by at least one normal fault below Guaje Canyon. This fault is located approximately 1,500 ft east of well G-2a. Surface expressions of faulting were previously mapped in the Puye Quadrangle by Dethier (2003).