Origin and Environment of the Tonganoxie Sandstone in Northeastern Kansas

Abstract

Study of lowermost deposits of the Virgilian Series (upper Pennsylvanian) in Leavenworth, Wyandotte, and Douglas Counties, northeastern Kansas, indicates localized development of sediment classed as belonging to the Tonganoxie sandstone member of the Stranger formation, which is the lowermost subdivision of the Douglas group in this region. The Tonganoxie rests disconformably on eroded upper Missourian strata consisting of evenly bedded shales and limestones.

The Tonganoxie sandstone mainly occupies and fills a wide, shallow, southwest-trending valley carved in the pre-Virgilian rocks. This valley, named Tonganoxie Valley, has a maximum width of nearly 20 miles and depth of 90 to 100 feet.

Four types of deposits are recognized in the Tonganoxie sandstone: (a) basal conglomerate, (b) sandstone, (c) shale, and (d) coal. The lithologic characters are stratigraphic relations of each of these types are described and interpreted. The filling of the Tonganoxie Valley is judged to have been accomplished by a southwest-flowing low-gradient river, named Tonganoxie River. In part, erosion and deposition in this area are concluded to have been contemporaneous.