QUANTIFYING WATER INFILTRATION INTO CORONADO CAVE AT CORONADO NATIONAL MEMORIAL, ARIZONA

Approximately 180m (600ft) long, 6m (20ft) high and 21m (70ft) wide, Coronado cave developed in Paleozoic limestone of the Naco Group that rests in the southernmost end of the Huachuca Mountains in Montezuma Canyon, Arizona. Composed of massive and marbleized limestone, Coronado Cave is bound by structural features, including a fault zone. It is the structural aspects of the cave and the surrounding geology that give rise to the presence of permeability structures that allow for water to continue infiltrating the cave system. The hydrology of the Coronado NMem. region and its relationship with Coronado cave have yet to be studied. The purpose of this pilot study is to determine water infiltration in the Coronado cave system in relation to regional rainfall occurring during the Arizona monsoon season. Infiltration data is used to measure water discharge in to the cave system through conduits and drips spots as well as measure drip frequency. Volumetric measurement of water infiltration is the preferred method to measure sites with small discharges; it is the most accurate method of measuring such flows. This method of data collection requires an observation of the time required to fill a calibrated container to a known volume and record the time that elapses. Water infiltration into any active cave system is critical for the creation and maintenance of speleothems. Collecting infiltration data will lend to a better understanding of the water cycle, contaminant transport, water management and resources, and speleothem growth that will aid in the maintenance for a healthy cave ecosystem. A hydrograph will be created and used for analysis of cave infiltration and will allow for easier comparisons with rainfall data.