GEOLEX

Summary of Citation: Duncan Mills

Publication:
Willman, H.B. and Frye, J.C., 1970, Pleistocene stratigraphy of
   Illinois: Illinois Geological Survey Bulletin, no. 94, 204
   p.

Usage in Publication:
Duncan Mills Member

Modifications:	Geologic Province:	Dominant Lithology:
Named	Illinois basin	Sand Gravel Silt

Summary:
Named as member of Glasford Formation (new) for Duncan Mills, Fulton Co, IL. Type section 4 mi south of Duncan Mills, exposures in Enion Section, NW SW SE sec 32, T4N, R3E. At type, consists of glacially derived sand, and sand and gravel with some silt, generally deeply weathered. Is bounded by Hulick Till Member (new) above and Kellerville Till Member (new) below; is recognized as a member only when it is contained between these two bounding till units. Is also described in the Cottonwood School, Lewistown, and Tindall School Sections (western part of Illinois basin). Clay mineral composition given in table 5. Is as thick as 30 ft and has previously been called Jacksonville-Buffalo Hart deposits (Wanless, 1957). Locally contains deposits in both the Monican and Liman Substages of the Illinoian Stage. Contains outwash of the retreating Kellerville glacier and deposits of the advancing Hulick glacier.