The onshore geology can provide direct access to critical rock formations and structures and is therefore able to add detail, support or modification to the story of the formation of the oceanic basins in the Arctic and North Atlantic, a story initially derived from offshore geophysical data. The CASE program has since been modified to the study of Circum-Arctic Structural Events, it has continued to the completion of expedition CASE 6 in 2000 and has been extended to include work in North Greenland, Ellesmere Island and Siberia. The general concept of onshore/offshore correlations, however, is unchanged.