Studies of Appalachian geology: northern and maritime. Edited by E-an Zen [and others] Zen, E-an, 1928- ed. Billings, Marland Pratt, 1902- Geology Appalachian Mountains. QE78.3 .S7 551.7 FIS Includes bibliographies. New York, Interscience Publishers [1968] [1968] 1968 Text xviii, 475 p. eng Appalachian Mountains.