The Waterways Formation is a basin facies probably of Late Devonian age, enveloping an oil-producing reef-fringed bank. It consists of nodular, argillaceous, micritic and micritic-skeletal limestones interbedded with massive and laminated micritic limestone and calcareous shales, with occasional beds of skeletal-micritic limestone and dolomite organic matter, pyrite, and clay minerals. Skeletal remains of invertebrate fauna are an assemblage of pelagic and benthonic forms. Depositional environment varied from quiet, stagnant water below wave base inhospitable to benthonic life to better oxygenated bottom conditions permitting a bottom community to develop. Samples from drill cores were examined mineralogically and petrographically, and insoluble residuestudies, X-ray analyses, and organic carbon determinations were made.