Ichnofossils are analyzed from three outcrops of the "Stalnaker" Sandstone [Tonganoxie equivalent] across a 3 ½ mile transect in southeastern Chautauqua County, Kansas. Two fining upwards parasequences composed of sandstone and shale are recognized based on ichnofacies and sedimentary structures present.
Abundant ichnofossils are well preserved in the three sections. Ichnogenera include: Paleophycus, Protovirgulana, Nereites, Cruziana, Lockeia, Ofivelfites, Aulichnites, Skofithos, and Chondrites. An arthropod trail is present at site 2.
Sedimentary structures include: flat-topped ripples, rill and runnel marks, small scale cross-bedding, and herringbone cross stratification. In the lower part of the succession at site 1, a sandstone unit containing herringbone cross-stratification, abundant fragmented body fossils, and intraclasts is identified as a probable maximum flooding surface (parasequence boundary).
Ofivelfites is present on the same bedding plane with Calamites plant fragments in the upper part of all three sections, indicating very shallow water. At site 3, runnel and rill marks are present, along with Aulichnites, in the troughs of flat-topped ripples, again indicating very shallow water.
Sedimentologic, stratigraphic, and ichnologic evidence suggests
deposition in a tidal flat environment, outside of the Tonganoxie
paleovalley.