Abstract

Analysis of recent seismic refraction data produces a water-loaded basement depth, sedimentation rate, and average sediment density for the central Canada Basin. Comparison of the corrected basement depth with an age-versus-depth relationship derived for the world’s oceans produces a probable age of the basin of 90-125 million years. With the calculated sedimentation rate and the average sediment density, heat flow values from the central Canada Basin can be corrected for radioactive heat generation in the sediment column and for the effects of rapid sedimentation. Assuming a reasonable range of sediment types and radioactive heat generation values, ages for the central Canada Basin based on age-versus-heat flow comparisons range from 80 to 110 million years.

An age of 90-125 million years for the opening of the central Canada Basin is 30-50 million years younger than that suggested by many other researchers. Many of their observations, based on nearby continental geology, may be confusing the initiation of continental rifting with the start of sea-floor spreading in the Canada Basin. The heat flow and the water-loaded depth to basement suggest that actual sea-floor spreading did not begin until approximately 125 million years ago and continued until about 80 million years ago.