Most fault lines in horizontal strata evolve through a series of erosional stages in which scarps are successively obliterated and redeveloped on deeper rocks. Strahler, 1960, p. 477.

The drainage pattern on a maturely eroded dome combines annular and radial elements. It resembles a trellis pattern bent into a circle. Strahler, 1960, p. 463.

Rock breakup takes various forms. Granular disintegration, exfoliation, joint-block separation, shattering. Strahler, 1960, p. 312.

Development of sea cliffs. A. Breaking waves first cut out a small cliff, or nip. B. As the cliff is cut back it develops undercut notches, arches, stacks, and crevices. At the same time an abrasion platform, shore face terrace, beach, crevice. C. When equilibrium has been reached a broad platform is present and the cliff is no longer actively undermined. Strahler, 1960, p. 416.

Diagram showing the cycle of land-mass denudation in a humid climate. A. In the initial stage relief is slight, drainage poor. B. In early youth, stream valleys are narrow, uplands broad and flat. C. In late youth, valley slopes predominate, but some interstream uplands remain. D. In maturity, the region consists of valley slopes and narrow divides. E. In late maturity, relief is subdued, valley floors broad. F. In old age, a peneplain with monadnocks is formed. G. Uplift of the region brings on a rejuvenation, or second cycle of denudation, shown here to have reached early maturity. Strahler, 1960, p. 251.

As a stream progresses from youth to maturity its valley walls become gentler in slope and the bedrock is covered by soil and weathered rock mantle. Strahler, 1960, p. 353.

Diagram of geologic section at South Haven, Michigan showing the change in percentage of tree pollen recovered from various layers. The peat bed has been correlated with the Chippawa low-water stage in the Lake Michigan basin. Other pollen profiles from nearby indicate that the oak peak was reached about 3500 years ago, and since then oak has decreased and white pine has increased. This has been interpreted as a revertence to a colder climate during the last 3500 years (Zumberge 1958, p. 365).

Diagram showing stages in the erosional development of folded strata. A. While folding is still in progress, erosion cuts down the anticlines, alluvium fills that synclines, keeping relief low. B. Long after folding has ceased, erosion exposes a highly resistant layer of sandstone quartzite. C. Continued erosion partly removes the resistant layer of sandstone and quartzite. C. Continued erosion partly removes the resistant formation but reveals another below it. D. peneplanation reduces the fold belt to low relief, but the hard rock still show. Strahler, 1960, p. 472.

Diagram showing stages in the development of a mountainous dome. Strahler, 1960, p. 463.

A sequence of events which have generally been repeated throughout geologic time over the continents of the globe is well illustrated in the Hudson Valley. In the diagrams, northwest is to the left, southeast to the right. A. In a shallow inland seaway thousands of feet of sediment accumulated during the Palaeozoic era. B. Mountain building at the end of the Palaeozoic era produced a series of folds and thrust faults. A general uplifting brought a large mass above sea level. C. Followings long period of erosion, a peneplain was produced. Then faulting in the Triassic produced gently tilted blocks. D. Second long period of erosion resulting in another peneplain. E. The region today owes its relief to different rates of removal of the various kinds of rocks. Strahler, 1960, p. 296.

Metamorphic rocks tend to form elongate parallel belts in valleys and mountains. Strahler, 1960, p. 284.

Land masses can be classified according to the groups illustrated here: Coastal plains, horizontal strata, folds, domes, fault blocks, homogenous crystalline masses, complex structures,volcanoes. Srahler, 1960. p. 449.

Slump rocks rotate backwards as they slide from a cliff. Strahler, 1960, p. 323.

Hogbacks may gradually merge into cuestas, the cuesta into plateaus and esplanades, if the dip of the strata becomes less from one place to another. Subsequent stream, hogback ridge, cuesta, mesa, esplanade, cliff, plateau. Strahler, 1960, p. 463.

A. Coastal blowout dunes with saucer-like depressions. B. Parabolic blowout dunes on an arid plain. C. Parabolic dunes of hairpin form. D. Longitudinal dune ridges on a desert plain. Srahler, 1960. p. 439.