DIRECTIONAL MAGNETOTELLURIC SPECTRA AT GARCHY, NIVRE,

Abstract

Performance of magnetotelluric soundings in surroundings of the geophysical center of Garchy has given, starting from the surface of the ground, the following results: (l) in a '3 sheets complex,' the existence of sedimentary layers, subhorizontals of a total thickness of about 1200 m. (2) A perturbed layer, for which magnetotelluric results, expressed in ohm-meters, are very dependent of the direction of the soundings. This, with a maximum of resistivity for, approximately, the azimuth 10 grade W, which corresponds to a direction quite parallel to the Loire valley and a minimum in an azimuth normal to the preceding one. (3) A layer in the Upper Mantle, of about 700 km of thickness and an apparent resistivity around 650 ohm-meters. (4) A layer of rather high conductivity may start around 750 km below the surface. (Author)

Document Details

Document Type
Technical Report
Publication Date
Nov 19, 1963
Accession Number
AD0428062

Entities

People

  • H. Fournier
  • S. H. Ward

Organizations

  • University of California, Berkeley

Tags

DTIC Thesaurus Topics

  • Conductivity
  • Diffraction
  • Directional
  • Geometry
  • Mathematics
  • Physical Properties
  • Spectra
  • Thickness

Readers

  • Geotechnical Engineering.
  • Materials Science and Engineering.
  • Seismology