Early Proterozoic ( Aphebian) sedimentary and volcanic rocks in Labrador are described from two tectonic belts: the Churchill Province of western Labrador, and the Makkovik Subprovince of eastern Labrador. The Aphebian in the Churchill Province is represented mainly by the Labrador Trough ( Kaniapiskau Supergroup) but also in the Laporte Croup, Lake Harbour Formation and Petscapiskau Croup. The Labrador Trough is the most completely exposed of these sequences and displays a transition {rom shelf sedimentation in the west, to deeper water basinal conditions in the east. Rifting along the eastern margin of the Labrador Trough may have produced a narrow proto-oceanic rift during this stage. Aphebian sequences in the Makkovik Subprovince are represented by the Maran Lake and Aillik groups. The Maran Lake and lower Aillik groups were deposited in environments broadly similar to those of the Churchill Province and in approximately the same time. The upper Aillik Group (17 50-1670 Ma) represents a younger assemblage dominated by f elsic volcanics intricately intruded by granites and may indicate the onset of radically diff erent tectonic conditions towards the end of Aphebian time.