Pg. 16 (table), 39, 40, 41. Delwood formation of Tradewater group. Formation contains only one important sandstone and one coal and is considered to represent a single cycle of deposition. Basal sandstone is about 50 feet thick, generally massive and cross-bedded and conspicuously micaceous; above the coal, formation consists of a succession of sandy shales and shaly to thin-bedded sandstones with a probable maximum thickness of 50 feet. Underlies Macedonia formation; overlies Grindstaff formation. Age is Pennsylvanian.
[Named from Delwood, a crossroads village in northern part of Pope Co., IL.]

Source: US geologic names lexicon (USGS Bull. 1200, p. 1086).

Pg. 9. Delwood formation in Tradewater group [?Delwood sandstone in Tradewater group]. Type locality designated. Age is Pennsylvanian.
Type locality: in sec. 5, T. 11 S., R. 6 E., Pope Co., southern IL.

Source: US geologic names lexicon (USGS Bull. 1200, p. 1086).

Pg. 31. †Delwood sandstone abandoned, so that name may be retained for the coal. Replaced with Finnie sandstone member, reallocated to Abbott formation (new) of McCormick group (new).

Source: US geologic names lexicon (USGS Bull. 1200, p. 1086); GNU records (USGS DDS-6; Reston GNULEX).

Nomenclature chart (fig. 10) reveals Murray Bluff Sandstone Member of Abbott Formation of this report referred to as Delwood sandstone by Potter (1957).

Source: GNU records (USGS DDS-6; Reston GNULEX).