Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 40.This volume contains many of the papers presented at the Sixth International Gondwana Symposium, held at the Institute of Polar Studies, The Ohio State University, Columbus, Ohio, August 19-23, 1985. The symposium was the first held outside the Gondwanaland continents; other symposia were held in Buenos Aires, Argentina, 1967; Cape Town and Johannesburg, South Africa, 1970; Canberra, Australia, 1973; Calcutta, India, 1977; and Wellington, New Zealand, 1980.The Columbus symposium attracted 150 scientist from 19 countries to five days of technical sessions, six field trips, commission and working group meetings, and workshops. Topics covered in the technical sessions were generally similar to those of earlier meetings and included reconstruction of Gondwanaland, vertebrate and invertebrate paleontology, biogeography, glacial geology, Gondwana stratigraphy, economic geology, and tectonics and sedimentation at plate margins. A notable difference was in geographic coverage. As might be expected at a meeting co-hosted by the Institute of Polar Studies and the Department of Geology and Minerology at The Ohio State University, the focus of the meeting was on Antarctica, with 45% of the 102 papers covering the Ross Sea sector, West Antarctica, and northern Victoria Land.