Reconstructing Surface and Subsurface Paleohydrology Using Evidence From Caves, Paleosprings, and Travertine in the Arbuckle Mountains, Southern Oklahoma, USA
The Arbuckle Mountains are a complex geologic province, characterized by thick sequences of intensely folded and faulted carbonates, sandstones, and shales of the Late Cambrian through Pennsylvanian. Severely deformed structures of these mountains have played a significant role in the development of subterranean conduits and fluvial systems. The development of hypogenic cave systems occurred by ascending fluids and internal corrosion, beginning as early as the Late Pennsylvanian. Subsequent burial during the Permian helped preserve the fossil terrane with clues to its origin and fluid anisotropy. The mountains have been eroded steadily since the Cretaceous, but evidence of off-set speleothems suggests gradual uplift associated with the Laramide epeirogen, which appear to have altered surface and subsurface flow-paths. Evidence of scallops on the walls of dry cave passages indicate various directions and velocity of subterranean fluids. During the Pleistocene, massive deposits of travertine accumulated along several stream systems. Remnants of once large waterfalls are found on dry hillsides, providing evidence of paleochannels that may be traced back to paleosprings. Surface incision into caves has formed swallow holes that has left channels abandoned from upstream flows. Some streams also appear to follow unroofed cave passages for some extent. Reconstructing the flow-paths from field datasets is providing clearer insights to a dynamic hydrologic system, which is controlled by complex geologic structures. Models of these past fluid-flow events provides clues to the occurrence of hypogene minerals, understanding the paleoclimates in which these systems formed, as well as predicting how these systems might evolve within various scenarios of our continually changing climate.
AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017