Abstract
The magnetic basement map computed from the 1950 Peace River aeromagnetic survey of 27,000 sq mi in western Canada is compared with the subsurface Precambrian surface determined by 169 deep tests subsequently drilled. The computed map has a standard deviation of 6.5 percent and an average error of 7.4 percent. The errors of the computed depth estimates are biased toward the shallow side; that is to say, the depth estimates are generally not deep enough. Moreover, excessive errors, those over 20 percent, are conspicuously shallow. This asymmetrical distribution is attributed to the failure to utilize plate models in the interpretation, as both intrabasement and suprabasement anomalies may be identified in the observed field. Consequently, the comparison confirms the existence of the intrabasement magnetization units within the Precambrian by establishing the validity of the coefficients derived from them and used in computing the depth estimates.