Geological History of the Northwest Passage

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract The broad structural geology and stratigraphy of the Northwest Passage is controlled by the Boothia Arch and structural depressions on each side, namely, Viscount Melville Sound and McClure Strait to the west (graben) and Lancaster Sound to the east (half-graben). Negative rift movements began during Mesozoic time and continued into the Tertiary. Outcrop and well information from the islands are related to marine seismic data in the Northwest Passage. Paleozoic strata appear to continue offshore in facies predictable from data on the islands. Mesozoic and Tertiary strata, however, are represented by sparse remnants on land, but are well developed under Lancaster Sound, if low velocity beds present there are of these ages. M'Clure Strait also seems to have thicker Tertiary and Mesozoic sediments than do the adjacent islands. Introduction The study area is large (Fig. 1). it occupies a region 900 miles long by 300 miles wide. An effort has been made to incorporate all literature on outcrop data as published by the Geological Survey of Canada and indus together with well information released to the public. These sources of data were combined public. These sources of data were combined with 14,000 miles of marine seismic information obtained throughout the Northwest Passage. At the time of writing no offshore wells have yet been drilled in the Northwest Passage. Fig. 2 shows the main geographic divisions. From east to west they are: Lancaster Sound, Barrow Strait, Viscount Melville Sound, and McClure Strait. The width of these sounds is approximately 50 miles, locally widening to 130 miles in Viscount Melville Sound, and narrowing to some 30 miles in Barrow Strait. PALEOZOIC STRATIGRAPHY PALEOZOIC STRATIGRAPHY Cambrian The Cambrian lithofacies and isopach map, Fig. 3, shows the Minto Arch, the Boothia Arch, and a third area named the Stable Shelf. The Stable Shelf is that area which was not greatly affected by post-Precambrian orogenic movements. It underlies the eastern part of Devon Island, northern Baffin Island and Bylot Island. Late Proterozoic sediments outcrop along the Minto Proterozoic sediments outcrop along the Minto Arch, whereas crystalline rocks of Archean age are predominant on the Boothia Arch and Stable Shelf, with local outcrops of late Proterozoic sediments.