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Glaciation should now be treated as a regularly repetitive process, not as an irregular process through geologic time. If so, the changes in volume of the world ocean (glacio-eustasy) may be expected to account primarily for the major advances and retreats of the sea (the "pulsations" of Grabau) that arc global and characteristic of all continental platforms (cratonic margins). These larger cycles, best termed stages (equivalent to the "megacycles" or "megacyclothems" of Moore, and to the "mesothems" of Ramsbottom), resemble the Quaternary Model, whether comparison is made with sedimentary cycles of the Paleozoic, Mesozoic, or Tertiary. Conversely, the Quaternary may be considered as a stage (or megacyclothem), seemingly composed of six coupletcyclothems that diminish in intensity toward the present. Unconformities arc taken to occur at glacial maxima, representing twelve (six-double) glaciations: whereas the strong soils are interpreted as interglacials and the weak soils as interstadials. We should be approaching the end of the Quaternary Stage, if the model is the same as for earlier stages, but docs that not mean that we should expect the next one to begin soon after?
The comparison of this Quaternary Model with earlier stages should be considered as both a powerful new research tool and as a theory. As a topic, it may be a new scientific discipline, Comparative Stratigraphy. If these concepts prove to be valid, the causes for glaciation should be sought in the Sun, and diminishing cyclicity (cyclic sedimentation) should be tested for a possible relation to a damped-Fourier series. However, we should build on the Tradition, not toss it aside.