Fig. 198.—Diagram looking up the valley, showing two terraces below, one in the middle, and none above. The relations are purely diagrammatic.

The topography of terraces is similar to that of flood-plains, except in so far as modified by erosion. While flat in general, the terrace may slope either toward or from the valley bluff, and its surface may be marked by all the minor irregularities which characterize a flood-plain.