Theorems and relations describing a system of horizontal layers are considered as the elements of a meta‐system having a layered structure. This implies a layered structure of a solution of geophysical problems for horizontally stratified medium. Wave equation, Laplace's equation, and Maxwell's equations are the special cases of a more general differential equation. By separation of variables the basic equation for layered structures is obtained. A multi‐layer medium may result from accumulation of successive layers. The descending or ascending accumulation is possible, depending whether the successive layers are inserted at the top or at the bottom of the medium. The discretization of a basic equation provides two sets of formulas for descending or ascending accumulation, respectively. The relationship between the mathematical expressions of the seismic transfer function and the magnetotelluric input impedance is derived. The deduction leads to the possibility of converting the magnetotelluric observations into an equivalent synthetic seismogram. Copyright © 1979, Wiley Blackwell. All rights reserved
