The surface of Newfoundland is complex and owes its character mainly to erosion on complex rock structure, differences in rock resistance, and differential and periodic uplift. Depositional agencies are responsible for some parts of the surface. Striking features are the slight relief of large areas of the upland surface and the rather generally steep slopes to the lowlands. Most steep slopes seem to be fault line scarps. Most lowland areas are on weak rocks.
The highest upland surfaces of slight relief are on the west coast and range in elevation from about 2000 to 2600 feet. This upland surface has been named the Long Range Peneplain. It is represented in the interior of Newfoundland by summits of monadnocks. A second surface of slight relief is represented in the western mountains by high-level valleys in the range of elevation between 1300 and 1700 feet. This is continued eastward over the High Central Plateau of the western part of the interior by a surface of little relief with elevation between 1200 and 1600 feet, and still farther eastward by summits of monadnocks and plateaulike areas in the range of elevation of 1000 to 1200 feet. On the Avalon Peninsula it is represented by upland areas of little relief with elevation of 700 to 800 feet; this has been named the High Valley Peneplain. A third erosion surface on the west coast is represented by dissected upland surfaces from 1000 to about 1100 feet above sea level and by wide mature valleys from 500 to about 1000 feet above sea level.
In the central interior this surface is between 500 and 1000 feet high and it descends to about 200 feet above sea level on the Bay of Exploits. It is about 400 feet high at the Newfoundland Airport and has about the same elevation on the Avalon Peninsula. This has been named the Lawrence Peneplain.
The surface of the parts of Newfoundland studied is described in detail, general summaries of data are made, and interpretations of origin are attempted.