FINDING HOLES IN A THEORY OR FINDING A THEORY IN HOLES – THE POTENTIAL ROLE OF HYPOGENE SPELEOGENESIS FOR CAVES OF THE CUMBERLAND PLATEAU IN SOUTHEASTERN KENTUCKY
In this study, we document instances of upward flow in a sub-aqueous environment, such as rising half-tubes leading toward cupolas, blind passages, and possible bubble tracks. We also note that these caves are located near or within shallow oil reservoirs and that natural seeps of petroleum persist along surface and cave streams. Our hypotheses for this upward flow ranges from sediment aggregation linked to glacial cycles, localized confinement by the Lost River Chert, or rising sulfide-rich brines from underlying petroleum reservoirs. We are using δ34S within petroleum seeps and gypsum samples from caves to test the last of these three hypotheses. The range of δ34S in gypsum is 0.0 and +11‰. The range in dissolved SO4 and H2S at seeps is +17 to +24‰ and -13 to +6‰, respectively. The depleted δ34S of H2S in the brine indicate microbial-mediated fractionation. While these results may support the possibility that microbial-derived H2S plays a role forming the in-cave gypsum, it is very important to note that other possibilities, such as pyrite oxidation, have not been tested.