Abstract

The Canadian Arctic Islands sedimentary basins cover an area of approximately 664,600 square miles, with a land area of 286,00 square miles, and contains an estimated 950,000 cubic miles of Phanerozoic sediment.

The area consists of 4 major structural provinces. (1) The bordering Precambrian shield areas have structural arches that extend into the basin. (2) The central stable region consists of several basins containing relatively flat-lying shelf carbonates of Ordovician-Silurian age that generally are 5,000 feet thick within the basin and thicken northward to a maximum of 15,000 feet. (3) The Innuitian region is a mobile belt characterized by thick sedimentary deposits which was tectonically active from the Paleozoic to the Tertiary. The region is comprised of the Franklinian fold complex and the Sverdrup basin. The Franklinian fold complex includes the various structures formed from a gently folded lower Paleozoic geosyncline, approximately 1,500 miles long. It contains up to 16,000 feet of Or-dovician and Silurian carbonates, evaporites and shale; up to 6,000 feet of Lower Devonian clastic rocks, and 16,000 feet of Middle and Upper Devonian sedimentary rocks ranging from marine carbonates and elastics to nonmarine elastics. The Sverdrup basin, a NE-SW trending basin approximately 600 by 200 miles contains up to 40,000 feet of post-Devonian to mid-Tertiary rocks. Permo-Pennsylvanian strata are predominantly carbonate and evaporite. The Mesozoic through lower Tertiary is dominated by heavy and continuous sedimentation. The stratigraphic section consists mainly of terrigenous clastic sediments which include basinal shales and marginal or deltaic sandstones, and lesser amounts of volcanic and carbonate rocks. The axis of the basin is characterized by numerous evaporite diapirs. (4) The Arctic coastal plain lies along the northwest edge of the Arctic Islands, bordering the Arctic Ocean in the position of the present continental shelf. It contains upper Tertiary and Pleistocene sedimentary rocks.

The Arctic Islands sedimentary basin has all the necessary geologic elements conducive to the entrapment of hydrocarbons in large quantities. There is a very thick, lithologically varied, stratigraphic succession representing every geologic period, adequate source beds, and abundant potential reservoir rocks. There is an abundance of diversified traps — large anticlines, reefs, evaporite domes, faulted homoclines, unconformities, and facies changes. Hydrocarbon shows, including “oil sands,” stain, and bitumen are present in a large area and in a wide range of ages. Large quantities of gas have been discovered at two localities.