HYDROGEOCHEMICAL ANALYSIS OF SPRINGS IN THE CIBOLA NATIONAL FOREST: IMPLICATIONS FOR SPRINGS/WETLANDS SUSTAINABILITY & GEOCHEMICAL RESPONSE TO FOREST FIRE

Aridland springs of the Southwest provide habitat for many species and important resources for local communities. The Manzano mountains of north-central New Mexico provide important sources of recharge to springs, local wetlands, and regional groundwater basins. Ojo del Rancho del Medio (ODRDM) and Ojo del Rancho del Medio West (ODRDMW) springs within the Mountainair District of the Cibola National Forest are the focus of this study. Regionally, springs are associated with the Madera Group of Pennsylvanian age, dominated by carbonate lithologies.

We use a multidisciplinary approach to quantify spring sustainability, determine the sources and pathways to springs, and assess the response to wildfire of these springs. This region of the Manzano mountains experienced a forest fire in 2016. Water quality monitoring began during the summer of 2019 and will continue until the spring of 2021.Water samples have and will be collected for analyses of major ion chemistry and stable isotopic analysis of deuterium and oxygen in order to determine the flow path, recharge mechanisms, and to determine the sources of soluble ions of these Manzano mountains spring waters. Monitoring (pH, temperature, conductivity, turbidity, and DO) for selected time intervals will help connect water quality to spring discharge, documenting change across rainfall events as well as seasonally. Total solid chemistry and batch mobility experiments will be conducted on the ash, soil, sediments, and bedrock to determine likely sources of solutes into spring waters with particular focus on the mobility of ions from ash deposits in the Dog Head Fire of 2016.

Preliminary analyses in show isotopologues (δD and δ¹⁸O) of the study springs are within the range of observed values for the nearby Sandia mountains consistent with winter recharge mechanisms. Preliminary major ion geochemical analyses similarly show these springs are consistent with other Sandia mountain springs issuing from the Madera Group carbonates.

Monitoring of the water quality of these springs will provide a baseline of the seasonal hydrochemistry and assist in understanding the sustainability of these springs based on the affects from land management decisions and the influence of forest fires.