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Can remanent magnetization in the deep crust contribute to long wavelength magnetic anomalies?
Author(s) -
Shive Peter N.
Publication year - 1989
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl016i001p00089
Subject(s) - remanence , magnetization , crust , geology , magnetic anomaly , geophysics , wavelength , natural remanent magnetization , rock magnetism , stoner–wohlfarth model , demagnetizing field , condensed matter physics , magnetic field , physics , optics , quantum mechanics
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 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 remanence, the viscous component will 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.