Gravity and Deep Structure of the Continental Margin of Banks Island and Mackenzie Delta

• Published in: Canadian Journal of Earth Sciences
• Main Author: Sobczak, L. W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1975
• Subjects: Banks Island; Mackenzie Delta
• Online Access: http://dx.doi.org/10.1139/e75-035; http://www.nrcresearchpress.com/doi/pdf/10.1139/e75-035

Regional and deep structure supported by drill hole, gravity, and seismic evidence is interpreted along five profiles—one across the Mackenzie Delta and four across the continental margin. Isostatic compensation has reduced the gravity effect of most structures but gravity anomalies are still sufficient to outline two major sedimentary basins—one very extensive and thick (>10 km) underlying the continental margin and Mackenzie Delta and the other narrow and shallow east and southeast of the Arctic Coastal Plain. A basement ridge separating these basins along the eastern side of the Arctic Coastal Plain is outlined by a trend of relative gravity highs.An arcuate belt of prominent elliptically-shaped free air gravity highs (peak values >100 mgal) over the continental break outlines an uncompensated region of mass excesses. These mass excesses are explained by pro-grading wedges (>2 km thick) of Quaternary and possibly Tertiary sediments that have displaced seawater and act as a load on the crust rather than by the alternative concepts of an uncompensated ridge or high density material in the basement.