Petrology of Bethel sandstone of south-central Illinois

At head of title: State of Illinois, Dwight H. Green, Governor. Dept. of Registration and Education, Frank G. Thompson, Director. Division of the State Geological Survey, M.M. Leighton, Chief, Urbana."Part of a thesis on The Bethel sandstone of south-central Illinois submitted ... for the degree of Doctor of Philosophy at the University of Chicago, (1942)"--P. 63."Reprinted from Bulletin of the American Association of Petroleum Geologists, vol. 28, no. 1 (January, 1944)."Includes bibliographical references