Northwest Greenland embraces the broad peninsular region fronting westward upon Kane Basin, Smith Sound, and Baffin Bay, between Humboldt Glacier on the north and Melville Bay on the south. This peninsular region extends over 3° latitude, from about 76° to 79° N. and over 8° of longitude, from about 64° to 72° W.
The high narrow plateau between the ice-cap and the sea is bisected by Inglefield Gulf, a deep indentation with several tributary fjords. Wolstenholme Sound again bisects the southern half and Foulke Fjord bisects the northern half. The northern portion from Foulke Fjord northward, and the southern portion from Wolstenholme Sound southward are Laurentian gneiss and granite, in places capped by later sedimentaries; the area between Wolstenholme Sound and Foulke Fjord is Huronian sandstones, limestones, and shales, intersected by dark traps and diabases.
The Huronian coastline is much indented, with narrow beaches at the mouths of the valleys and along the gentler slopes; the land-surface is varied, with high sharp mountains and deep canyon-like valleys in places, and lower, rounded hills and broad valleys in other places. The Laurentian coast line is smoother, with very few beaches; the land-surface is more uniformly high and deeply dissected. Everywhere the topography is comparatively rugged.
The coastal belt between the icecap and the sea which becomes free of ice and snow in summer is from 2 to 40 mi. wide. It is intersected by numerous glaciers, most of which reach the sea, though some do not. Areas separated by these glaciers vary in size from small tracts of a few acres, to large regions several hundred square miles in extent.