Willman, H. B., Elwood Atherton, T. C. Buschbach, Charles Collinson, John C. Frye, M. E. Hopkins, Jerry A. Lineback, and Jack A. Simon, 1975, Handbook of Illinois Stratigraphy: Illinois State Geological Survey Bulletin 95, 261 p.
T. C. Buschbach
The Lacey Member of the Mt. Simon Sandstone (Templeton, 1950, p. 155).
It is named for Lacey School, De Kalb County.
The type section of the Lacey Member of the Mt. Simon Sandstone is located 2.5 miles west of Lacey School, De Kalb County. The member is 1880-2070 feet deep in McQueen No. 1 boring (SW NE NE 27, 42N-3E) (sample set 1466).
The Lacey Member overlies the Mayfield Member of the Mt. Simon Sandstone.
Extent and thickness
The Lacey Member is 176-230 feet thick.
The Lacey Member is principally conglomeratic sandstone, although beds of fine-grained sandstone occur in the middle part and locally in the lower part. Beds of red shale are more common in the Lacey and higher members than in the lower members. Only the Lacey and higher members of the Mt. Simon are differentiated in northeastern Illinois (Buschbach, 1964).
Well log characteristics
Age and correlation
Environments of deposition
BUSCHBACH, T. C., 1964, Cambrian and Ordovician strata of northeastern Illinois: Illinois State Geological Survey Report of Investigations 218, 90 p.
TEMPLETON, J. S., 1950, Mt. Simon Sandstone in northern Illinois: Illinois Academy of Science Transactions, v. 43, p. 151-159.
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