SUBSURFACE FACIES ANALYSIS OF ROSE RUN SANDSTONE (UPPER CAMBRIAN) IN EASTERN OHIO

This study of the Cambrian Rose Run Sandstone conducted lithofacies and microfacies analysis from 4 cores from Holmes (well 2892), Coshocton (wells 2989 and 3385), and Morgan (well 2923) counties in eastern Ohio. The Rose Run Sandstone is primarily sandstone, but also includes thin but common mudstone intervals, and dolostone. There are a total of 13 siliciclastic lithofacies and 5 carbonate lithofacies. Intertidal deposits include heterolithic flaser bedded sandstone and mudstone (lithofacies SMf), heterolithic wavy bedded sandstone and mudstone (SMw), heterolithic lenticular bedded sandstone and mudstone (SMk) and interbedded planar laminated sandstone and mudstone (SMl), the latter interpreted as tidalites. Subtidal clastic deposits include medium-scale planar tabular cross-bedded sandstone (lithofacies Sp) and herringbone cross-bedded sandstone (Sx), massive sandstone (Sm), glauconite-rich sandstones (SMg), hummocky stratified sandstone (Sh) and massive (Mm), laminated (Ml) and convoluted bedded (MMc) mudstones. Sm is the most common lithofacies and SMg has the highest intergranular porosity. Interbedded carbonates include dolomudstones (lithofacies Cm), bioturbated and mottled dolo-mudstones (Cmm), dolo-grainstones (Cgmb), dolo-packstones with mud drapes (“cryptalgal lamination”) (Cpl), and dolo-packstones with mud rip-up clasts (“flat pebble conglomerates”) (Cpmr). Contacts between sandstone and carbonates are gradational, whereas sharp and erosive contacts may be found between sandstone and shale intervals (e.g., core 2923). The Rose Run Sandstone in this region is interpreted as a shallow marine environment of normal salinity, with extensive tidal flats, mixed siliciclastic-carbonate deposition, strong tidal influence, and with reworking of carbonate materials. Continuing studies are on reservoir compartmentalization in this unit.