%0 Journal Article %A MUNDRY, E. %T THE THIN‐LAYER PROBLEM IN GEOELECTRICAL PROSPECTING * %D 1978 %J Geophysical Prospecting, %V 26 %N 3 %P 581-594 %@ 1365-2478 %R https://doi.org/10.1111/j.1365-2478.1978.tb01618.x %I European Association of Geoscientists & Engineers, %X Abstract For a thin highly‐conducting layer with given longitudinal conductance the recurrence formulae for an n‐fold horizontally stratified subsoil are established for d.c. resistivity and magnetotelluric soundings. Similarly, a thin low conductivity layer with given transverse resistance is treated in the d.c. case and a non‐conducting intermediate bed in magnetotellurics. Model curves for a thin high‐ or low‐conductivity intermediate layer in the three‐layer case have been carried out, which may serve as an extension of the well‐known three‐layer diagrams for a Schlumberger configuration. The corresponding model curves in magnetotellurics are given. By numerical comparison of these curves with real three‐layer curves some diagrams have been developed to show the allowed thicknesses of the intermediate layer in the Schlumberger case and in the case of magnetotelluric sounding. %U https://www.earthdoc.org/content/journals/10.1111/j.1365-2478.1978.tb01618.x