Surface geologic exposures in the Arctic Islands are excellent. However, the sparse subsurface information from boreholes is limited to only a few of the islands.

Geology of the inter-island areas is speculative. Preliminary interpretations based on erosion and isostatic readjustments after the melting of the continental ice sheet may have to be revised after a review of geophysical data which now are becoming available. Block faulting with associated horst and graben development has become a conservative structural interpretation, whereas consideration of rift and drift hypotheses has gained popularity.

Recently obtained reconnaissance data indicate the possibility that an entirely different geologic section exists offshore. This conclusion is based on regional geophysical data obtained by government and industry. Magnetic and gravity surveys have covered much of the Arctic Archipelago. Seismic profiles in marine areas of the southern Arctic Islands indicate a wide range of large structures; refraction probes are useful in defining the velocity, and thus the possible geologic age, of these sedimentary units.