Rock stratigraphy of the Silurian system in northeastern and northwestern Illinois
By: [by] H. B. Willman.
Series: Illinois State Geological Survey circular 479; Circular (Illinois State Geological Survey) ;; 479.
Publisher: Illinois State Geological Survey
Published: 1973
Place of publication: Urbana
Language: eng
Number of pages: 55
Subjects: Geology, Stratigraphic -- Silurian.; Geology -- Illinois.
Notes: Bibliography: p. 40-44.
Cover title.