Free-air and Bouguer anomaly maps have been compiled from about 9,000 gravity measurements made throughout the Canadian Arctic Archipelago and the Arctic Ocean. These measurements were made as part of a major study of the Arctic being carried out by the Canadian government.

The major feature of the free-air anomaly map is a series of large positive elliptically shaped anomalies overlying the continental margin and striking parallel with the continental break. These anomalies, which are approximately 120 km wide and between 150 and 300 km long, have amplitudes in excess of 100 mgal and regional horizontal gradients as large as 2.3 mgal/km. Interpretation of the gravity data, using seismic and geologic data for control, indicates that a composite structure consisting of a sedimentary layer up to 10 km thick and a crust which thins as much as 17 km can best explain this large positive anomaly with relatively steep, horizontal gradients.

Correlation of Bouguer anomalies with geology and physiography shows that negative anomalies occur over sedimentary basins and mountainous regions and positive anomalies occur over folded belts and the ocean basin.

Regionally, the Archipelago west of 90°W long. appears to be in approximate isostatic equilibrium as the average free air anomaly is about 7 mgal. The mean elevation for the same area is 15 m.

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