ABSTRACT
The origin of solutional caves has been the subject of considerable controversy for some time. In its infancy, karst science was highly descriptive and many early concepts attributed cavern development to catastrophic events or scouring of rock by subsurface streams. Geologic structure, in part, controls collapse of passage ceilings, a process that may block active conduits and lead to backflooding, development of diversion routes, and excavation of maze passages. The interior topography of the Edwards Plateau is undulating to slightly rolling and is moderately dissected by drainage systems flowing southeast to the Gulf of Mexico. However, the Balcones Escarpment along the south and east plateau margins is deeply dissected by streams, and slopes are correspondingly steeper there than in the plateau interior. The area contains a remarkable diversity of bedrock types, ranging from sedimentary units in the plateau proper to metamorphic and igneous rocks in the Llano Uplift.
