Series 10, Francis J. Pettijohn, 1883-1989, is divided into four subseries. Subseries 1, Correspondence, 1934 to 1946, consists of Pettijohn's correspondence while he was at the University of Chicago. The correspondence is arranged chronologically within each folder and the folders are arranged alphabetically by subject matter. Subseries 2, Correspondence, 1923-1989, consists of Pettijohn's correspondence while at the University of Minnesota, the University of Chicago and The Johns Hopkins University. The correspondence is arranged chronologically within each folder and the subseries as a whole. This subseries overlaps subseries 1, but apparently was maintained separately since its creation. Subseries 3, Geology History Sources, dates from 1935 to 1987 and contains materials used by Pettijohn while writing a history of geology at Johns Hopkins. There is only a small amount of material in this subseries, including letters to Pettijohn in response to his own inquiries about certain persons, photocopies from publications, and a few original letters. Files are arranged in alphabetical order by the name of the person whom they concern. Subseries 4, Subject Files, 1923-1987, relates to grants, lectures, tours and correspondence, especially about the publication of his textbook Sand and Sandstones and the merging of the Departments of Geology and Oceanography into the Department of Earth and Planetary Sciences. Additional information regarding this merger and the publication of Pettijohn's other books can be found in subseries 2.