Skip to Main Content
Skip Nav Destination

At least 10 marine-influenced stratigraphic intervals have been distinguished in the Kanawha Formation. Marine units range from 3 to 34 m in thickness and have been divided into component sedimentary facies based on lithology, body and trace fossils, sedimentary structures, paleocurrents, and geometry. Offshore facies consist of dark gray laminated shales, whereas nearshore and littoral deposits are typified by interlaminated to thinly interbedded very fine sandstone, siltstone, and shale. Current ripple bedding (flaser, wavy, lenticular) and ripple cross-lamination are widely developed. Tidal influence was significant and is reflected by rhythmic textures and structures and bipolar paleocurrents.

Phosphatic brachiopods and burrowing bivalves predominate in nearshore and littoral facies, while calcareous brachiopods dominate offshore facies and are often accompanied by bivalves, bryozoans, echinoderms, cephalopods, and corals. Primary faunal distribution was likely to have been controlled mainly by substrate, salinity, and dissolved oxygen.

Two trace fossil assemblages are common. The Olivellites assemblage has a high diversity and is represented by both infaunal burrows and surface tracks and trails developed in the nearshore zone and low- to midtidal flats. The Phycodes-Zoophycos assemblage is a low-diversity assemblage of infaunal deposit feeders formed in upper tidal flats, restricted bays, and tidal creeks.

Lowstands of sea level caused incisement of fluvial channels, whereas rising sea level led to expansion of tidal plains and estuaries. Shoreface retreat produced ravinement surfaces and transgressive lags that now separate coastal plain and marginal marine facies from shallow subtidal facies. Coastal progradation began during highstands after estuarine sediment sinks had filled and may have intensified during falling sea level.

You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Close Modal

or Create an Account

Close Modal
Close Modal