Stratigraphy, Petrology, and Depositional Environment of the Sulphur Springs Formation (Upper Devonian - Lower Mississippian), East-Central Kansas

The Sulphur Springs Formation consists of four members, in ascending order: the Upper Devonian (Famennian) “Allenton siltstone,” named herein; Glen Park Limestone, Bushberg Sandstone, and Lower Mississippian (Tournaisian) Bachelor Sandstone. Isolated exposures of this formation crop out irregularly and unconformably overlie Ordovician strata along the northeastern flank of the Ozark Uplift in east-central Missouri. The type section for the Sulphur Springs Formation is placed in the abandoned Goetz Quarry, Glen Park, Jefferson County, Missouri. Petrographic studies reveal nineteen lithofacies, a variety of diagenetic effects and sedimentary structures, and indicate a range of shallow, mixed-marine to marine, nearshore depositional environments. The bedded and laminated siltstones of the “Allenton member” exhibit silt- to sand-sized terrigenous grains and an impoverished benthonic fauna. These lithofacies suggest a low turbidity, relatively anoxic, clastic-influenced, and possibly a physically restricted environment. The multifacied Glen Park Member consists of sediments derived from both a terrigenous and diverse allochemical source. Abundant marine biota with associated micrite envelopes connote organic proliferation in an oxygenated, well-lighted, marine environment of normal salinity. Turbidity generally was low. Supersaturation of calcium carbonate promoted ooid formation in a wave-agitated water. The Glen Park Member possibly was deposited in a variety of both quiet and agitated environments that were warm, well-circulated, shallow, and nearshore. The Bushberg Member contains texturally submature to mature litharenites, sublitharenites, and quartz arenites. These lithofacies are composed predominantly of reworked, subrounded to rounded, fine-to coarse sand-sized, monocrystalline quartz grains. Each lithofacies displays varying percentages of either ooids, marine bioclasts, and reworked terrigenous phosphate pebbles, chert, and/or limestone lithoclasts. Deposition of the Bushberg Member occurred in a turbulent, nearshore setting that winnowed out the fine-sized sediments. The Bachelor Member, a supermature quartz arenite, possibly represents reworking of the underlying Bushberg Member. The mineralogical and compositional characteristics of most of the sediments in Sulphur Springs Formation suggests derivation from a simple terrane of Lower Paleozoic sedimentary strata. An emergent Ozark Uplift, the result of late Middle Devonian anorogenic tectonism, shed abundant detritus towards an eastward-facing, subtropical, dry belt coastline. The ideal depositional environment and climatic scenario for the Sulphur Springs Formation might have resembled parts of the modern central Texas Gulf Coast and/or the Trucial Coast of the Persian Gulf