Hypothetical High Tides

Abstract

WHATEVER conclusion may ultimately prevail with regard to the existence of very high tides in the earlier epochs of which geology has cognisance, I think that geologists will hardly accept the argument by Prof. Newberry, in your last issue (p. 357) as a settlement of the question. He appears to confound together three agents whose effects widely differ, viz.: (1) tidal waves of undulation, (2) tidal waves of translation, and (3) wind waves. In waves of undulation the particles of water move only in a vertical line, and can obviously neither denude nor transport. Waves of translation, acting as currents, are transporting agents, but are very subordinate to wind waves in their denuding power. In the present state of things waves of translation, i.e. the tides of our inland seas and estuaries, can hardly be said to denude at all; they simply shift mud and sand from place to place. Even if their speed were enormously increased, their effect as denuding agents must still be very inferior to that of wind waves.