Francis J. Pettijohn, widely known as the founder of modern sedimentology, died April 23 at the Glen Meadows retirement community in Glen Arm. He was 94.
As chairman of the Department of Geology at Hopkins from 1963 to 1968 and a member of the faculty from 1952 until his retirement in 1973, Pettijohn and his graduate students conducted a sweeping study of sedimentary development and destruction of the Appalachian Mountains chain. He was the author or co-author of more than 24 books, one of which, Sedimentary Rocks, has remained a standard in the field for more than 30 years.
According to Pettijohn's autobiography, Memoirs of an Unrepentant Field Geologist, his fascination with rocks began as a child in Bloomington, Ind., where he explored limestone caves and quarries and collected fossils.
As a geologist, he often traveled by foot and boat into remote back country for days at a time, journeys that earned him a reputation not as a theoretician but as a dogged scientist in the field.
Pettijohn was a member of the National Academy of Sciences and recipient of numerous prestigious awards, including the Penrose Medal from the Geological Society of America and the Wollaston Medal from the Geological Society of London. An award from the Society for Sedimentary Geology, the Francis J. Pettijohn Medal, was named in his honor.
He is survived by a son, Loren Pettijohn of Lutherville; two daughters, Norma Friedemann of Evanston, Ill., and Clare Maher of Philadelphia; a brother, Richard Pettijohn of Naples, Fla.; a sister, Elizabeth Dedolph of Reno, Nev.; nine grandchildren; and four great-grandchildren.