A detailed continuous seismic-profiling survey was conducted on the continental shelf off southern Oregon between Cape Blanco and the Oregon-California border during the summers of 1967 and 1968. This part of the shelf is divided into northern and southern regions, which appear to be unrelated structurally. The surface trace of a prominent angular unconformity, which crosses the continental shelf in a WSW direction between Cape Sebastian and the Rogue River, is the dividing line between the two regions. A series of folds parallel or subparallel with the coastline characterizes

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the structure of the northern region. Folding is most gentle on the outer continental shelf; the number of folds increases toward the present coastline. The fold amplitudes appear to be independent of the distance from shore. These fold trends are disrupted in the vicinity of the Rogue River where the Gold Beach shear zone appears to extend offshore. The southern region is dominated by a large sedimentary basin with a synclinal axis trending approximately S65°W from Cape Sebastian. This basin extends across the entire continental shelf and has been only slightly deformed by local folding or warping near the coastline.

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