Frontispiece 1. Relief map showing the setting of all sites drilled during Leg 189. Site 1168 is on the segmented and canyoned western Tasmania margin, Site 1172 is on the isolated east Tasman Plateau, and the other sites are on the South Tasman Rise. Strike-slip motion along the western margin of Tasmania (north northwest-south southeast) is shown by one major fault scarp formed >43 Ma. Similar motion along the western margin of the South Tasman Rise and within the rise (north-south) is shown by several fault scarps formed 43–33 Ma.

Frontispiece 2. Leg 189 core across the Eocene/Oligocene boundary on the East Tasman Plateau, showing gray late Eocene mudstones, green latest Eocene glauconitic siltstones, and white early Oligocene chalks. This core reflects profound changes that occurred as the Tasmanian Gateway opened.