H. B. Willman and John C. Frye
The Hagarstown Member of the Glasford Formation was informally named the Hagarstown beds by Jacobs and Lineback (1969, p. 12), for the south-central Illinois region. It was named for Hagarstown, Fayette County, 5 miles west of the type section.
The type section is the Hickory Ridge Section (Jacobs and Lineback, 1969, p. 20), SW NW Sec. 30, T. 6 N., R. 1 E., Fayette County.
The Hagarstown Member lies stratigraphically above the Vandalia Till and contains the Sangamon Soil at the top. It is commonly overlain by Wisconsinan loesses.
Extent and thickness
It is probably more than 100 feet thick in some of the higher ridges. In surface expression the Hagarstown Member is the material of the elongate ridges, referred to as the "ridged drift," and of the sheet of dominantly water-laid sediments between the ridges. Its geographic distribution, origin, and composition have been described by Jacobs and Lineback (1969).
It consists of gravelly till, poorly sorted gravel, well sorted gravel, and sand.
Age and correlation
The Hagarstown Member is in either the early Jubileean or late Monican Substage of the Illinoian Stage.
JACOBS, A. M., and J. A. LINEBACK, 1969, Glacial geology of the Vandalia, Illinois, region: Illinois State Geological Survey Circular 442, 24 p.
|Stratigraphic Code||Geo Unit Designation|