LATE QUATERNARY SEA-LEVEL CHANGES ON BROCK AND PRINCE-PATRICK ISLANDS, WESTERN CANADIAN ARCTIC ARCHIPELAGO

Emerged shorelines are few and poorly defined on Prince Patrick and Br ock islands. The sparse radiocarbon dates show emergence of only 10 m through the Holocene on the Arctic Ocean coast, increasing to > 20 m 1 00 km to the east. Hence, from Brock Island, representative of western -most coasts, the sea level curve since the latest Pleistocene has a v ery low gradient, whereas on eastern Prince Patrick Island the curve t akes the more typical exponential form. A decline in isobases towards the west is thus registered. Drowned estuaries, breached lakes, and co astal barriers, particularly in southwest Prince Patrick Island, sugge st that the sea is now transgressing at a rate that decreases towards the north end of the island, hence there is also a component of tilt t o the south. Delevelling is assumed to result from undefined ice loads , but may have a tectonic component. The sole prominent raised marine deposit is a ridge probably built in a period of more mobile sea ice, possibly at a time of stable or slightly rising sea level in the middl e or early Holocene. It winds discontinuously along several hundred of kilometres of the shores of the Arctic Ocean and connecting channels, declining to the south.