Mechanism of one variety of glacial-marine sediment transportation and deposition is inferred from observation of the activity of ice island T-3. This iceberg carries a significant sediment load. As T-3 moves with the Arctic pack ice, several meters of ice melt annually, releasing sediment to the ocean floor. The sediment accumulates at rates measured in a few mm per 1,000 years but in remarkably homogenous layers. This uniform sedimentation in a seemingly heterogeneous environment is unexpected. The uniformity results from clockwise rotation of the pack ice that transports T-3-sized icebergs at rates up to several km/day in constant patterns. T-3 currently is in at least its third traverse of the Amerasian Basin during the past 30 years. The consistent Arctic surface cur ents have brought T-3 over the same areas during the different cycles.

There has been little change in central Arctic sedimentation since at least the late Miocene. Late Cenozoic layers of glacial-marine sediment on the Alpha Cordillera have been organized into thirteen lithostratigraphic units. Even thin units can be correlated over several hundred thousand square kilometers. A textural classification of Arctic glacial-marine sediment recognized four classes, all forming since the late Miocene in the Alpha Cordillera region.

Quantities of glacial ice, bearing sediment derived from similar source areas and transported in similar patterns by constant ocean basin currents, account for the uniform glacial-marine sediment in the Arctic Ocean.

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