01074cam a22002771 4500 gs 28000083 DLC 20260227111332.0 790607s1927 ilua b s000 0 eng gs 28000083 (OCoLC)5045249 DLC TxCM OCoLC DLC premarc QE105 .T5 Thwaites, F. T. (Fredrik Turville), 1883-1961. Stratigraphy and geologic structure of Northern Illinois, with special reference to underground water supplies, by R. T. Thwaites. Urbana, Illinois [Springfield, Jeffersons Printing and Stationery Co.] 1927. 49 p. illus. Illinois State Geological Survey Report of investigations no. 13 At head of title: State of Illinois. Department of Registration and Education. Division of the State Geological Survey. Plates folded in pocket. Bibliographical footnotes. Geology Illinois. Water-supply Illinois. Groundwater. 26621 26621