The subsurface sedimentary structures that make up New Harbour deltas were investigated using GPR to develop a model for the formation of the fossil marine deltas that are well preserved along the New Harbour coastline wherever large melt streams with a substantial sediment load occur. GPR surveys were conducted on the deltas in the vicinity of Wales and Commonwealth streams, New Harbour, and on ... smaller sandy deltas between these sites. A preliminary interpretation of GPR images were used to target delta sediments for dating. Sediment units deposited via different processes at different times were selected from 12 sites and sampled for dating by the optically stimulating luminescence (OSL) technique. At several sites, samples of in situ articulated valves of the bivalve Laternula elliptica were selected for radiocarbon dating from adjacent to the sediment sample sites used for OSL dating.