Читать книгу Structural Analysis and Synthesis - Stephen M. Rowland - Страница 32

The technique of gently bent layers for locating the intersection of a geologic surface with the surface of the earth may be roughly used if the surface has a simple change in dip and a structure‐contour map can be constructed. In Figure 2.15a, three attitudes of a marker bed are mapped and all are different. Assuming a constant slope and a gradual change in dip between outcrop points, a structure‐contour map may be constructed as follows:

1 Arithmetically interpolate between the known elevation points to locate the necessary elevation points on the surface (Figure 2.15b).

2 Draw smooth parallel structure contours parallel to the strikes at the outcrop points (Figure 2.15c).

3 Superimpose the structure contour map and the topographic map and mark the points where contours of equal elevation intersect (Figure 2.15d).

4 Connect these intersection points to produce the outcrop map (Figure 2.15e).