Glossary of Karst and Cave Terms
1. A formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs . 2. A ground-water reservoir. 3. Pervious rock that is completely saturated and will yield water to a well or spring. Historically the term has been applied to beds favoring early cave development, probably synonymous with some inception horizons .