The results of a series of refraction profiles made over the continental shelf south of Nova Scotia and extending down to the adjacent deep basin are reported. The resulting geologic and crustal sections show the manner in which the gradation from continent to ocean takes place. The Coastal plain sediments reach a maximum thickness of around 20,000 feet on the gently sloping area at the bottom of the continental slope and thin further seaward. The crystalline basement of metamorphic rocks and granites over Nova Scotia gradually thins under the continental margins and pinches out toward the ocean basins. It drops abruptly under the continental slope from 5000 feet to 20,000 feet. The Mohorovičić discontinuity is measured on a single profile at a depth of 52,000 feet under the continental rise.