Southampton Island, 41 214 km2, is situated between FOXE BASIN and HUDSON BAY. It combines the 2 basic regional relief types. Its north and northeast consist of undulating highlands of Precambrian SHIELD rocks, reaching elevations of 400 m and terminating in steep cliffs on Foxe Channel. In complete contrast, its south and southwest are made up of gently sloping flat-lying Palaeozoic rocks, forming limestone plains and plateaus of low relief (less than 200 m). Frost-shattered boulders and clayey gravels give the surface a desertlike appearance. Exposures of ancient reefs hint at the possible presence of hydrocarbons, but economically significant accumulations more likely lie offshore. The island was named for the earl of Southampton (1573-1624).