Premium
Bedrock Depth Estimates from Ground Magnetometer Profiles
Author(s) -
Birch F. S.
Publication year - 1984
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.1984.tb01413.x
Subject(s) - bedrock , geology , outcrop , metamorphic rock , magnetometer , basement , seismology , geophysics , igneous rock , geomorphology , mineralogy , magnetic field , geochemistry , archaeology , physics , quantum mechanics , history
Bedrock depths can be calculated readily from ground magnetic profiles using either Werner deconvolution or Fourier spectral analysis. For crystalline basement rocks of New England and eastern Canada, a vertical dike is a useful magnetic source model. Formulae for these methods are presented along with some practical guidelines for implementing them. Six field examples from metamorphic and igneous areas in New Hampshire show that bedrock depths from spectral analysis agree well with estimates from seismic refraction, from wells and from outcrops. The Werner estimates are much more variable but commonly bracket the others. At several of these sites, measurements by other geophysical methods would be impractical, more expensive, or restricted to certain times of the year.