New Mexico Geological Society Annual Spring Meeting — Abstracts

Effective groundwater management in geologically complex basins requires accurate characterization of aquifer geometry, heterogeneity, and structural controls on groundwater occurrence and flow. In 2025, the New Mexico Bureau of Geology and Mineral Resources initiated a multi-year statewide aquifer characterization program focusing initially on using airborne electromagnetic (AEM) methods to improve basin-scale identification and delineation of fresh- and brackish-water aquifers. During the first year, six regional helicopter-borne time-domain AEM surveys were completed across groundwater basins in southern and central New Mexico in collaboration with state, local, and consulting-industry partners. AEM surveys produce resistivity models that can be used to interpret lithologic variability, detect faults, delineate basin geometry, and assess groundwater salinity variations to depths of up to a few hundred meters below land surface. Geologic mapping and hydrogeologic analyses provide essential context for interpreting resistivity patterns to improve aquifer characterization. Complementary subsurface datasets, including well summaries, borehole geophysics, groundwater-level data, and hydrogeochemical information are being systematically compiled to calibrate geophysical interpretations to aquifer properties. To further refine AEM interpretations, automated workflows have been developed to standardize an archive of ~170,000 historical driller’s logs. Additional tools are being developed to visualize and analyze AEM results, enabling more rapid and consistent evaluation of resistivity data. This program aims to establish a statewide, scalable 3D geological framework that integrates geophysics with hydrogeology, significantly enhancing assessments of fresh-water aquifers, optimizing monitoring-well network designs, and supporting the exploration of brackish groundwater to benefit water resource management across New Mexico.