The 255-ft-thick section reported on here contains only 8 to 9 percent insoluble material. Authigenic quartz is widespread as silt-sized and larger particles. There is little if any subsilt-sized silica in these rocks. Detrital quartz is very sparse except for the basal Curdsville Member. Illite is the only clay mineral group identified. A search for metabentonite proved negative although some admixture is probable. Pyrite is ubiquitous and amounts to units of percent of the insoluble residues. Dolomite is widespread, but minor in the formation. The limestones vary from micrite to coarse biosparite. The environment of deposition ranged from quiet to moderately agitated shallow water.