Long wavelength aeromagnetic anomalies require sources in the deep crust that are far more magnetic than the measured induced magnetization of lower crustal rocks. Several scientists have suggested that remanence in the deep crust may provide the missing magnetization. This is not likely, either through stable and/or viscous remanence. Bodies large enough to contribute to surface anomalies and carrying stable remanence probably cooled slowly enough that they are subdivided into zones enough that they are subdivided into zones of alternating polarity. This subdivision sharply reduces the power in the long wavelength portion of the anomaly spectrum. On the other hand, if such a body carries a viscous remance, the viscous component wil be acquired in such a way as to bring the total magnetization of the body into equilibrium with the earth's field. This equilibrium total magnetization is only about 25% greater than the induced magnetization, not enough to explain the discrepancy. ¿ American Geophysical Union 1989