John Wesley Powell

“ Thus the rate of corrasion is a function of force, of form and of kind, and hence there can be no equality between the work done as an effect and the energy as a cause. Again in transportation of the material the rate of transportation depends upon the rate at which the supply is furnished, and not upon the force of the waters, for the supply is load and the load adds its own weight to the gravitating energy. The condition of fineness in the particles constituting the load will greatly aid transportation; the larger particles will sink sooner, the smaller particles will be carried farther ”

“ If we now assume that all rocks flow tinder pressure, that the critical point is variable and that the modulus of compression is also variable, being greater for the lighter rocks and less for the heavier, and that this modulus is greatly accelerated at the critical point, we have a law which will regiment the facts of geonomy as the facts of astronomy are marshaled by the law of gravity. ”

“ Change the conditions in the two particles; let one of them be easily crushed and the other not, then one ball will rebound and the other will be shattered. Now action and reaction as force will still be equal, but cause and effect will be different conditions; one body has its course changed, the other body is shattered into fragments, and these fragments take different courses. Thus it is seen that between cause and effect equality cannot be asserted. There is no equality between a word of command and prompt obedience to the command. ”

“ That is to say, whenever we are examining the relation between cause and effect we are examining into conditions or states and not into equalities or inequalities of force. When a weight of a hundred pounds is raised a unit of altitude, the effect is a new position, and the force employed, which was one of the causes of the new position, is an action equal to the lifting of the weight as reaction. ”

“ IV In the change which comes in the development of the rocky cellate, forces become energies; that is, pari passu with metalogisis and metamorphosis there is metaphysisis; and metaphysisis is energy and work as reciprocals. The same fact is sometimes expressed in another form. The spherical members of the earth and the formations of which the crust is composed exhibit strains and stresses in their interaction and these strains and stresses produce changes. The varying heat of the ether by contraction and expansion rends the rocks and is an agency for their disintegration. ”

“ The elements of structure are set forth in a more elaborate form in structural geology when slaty structure, lode structure and stratified structure are the themes, and where flexures, faults, fractures and displacements are set forth in describing the structure of mountains, plateaus, hills and plains as slates, lodes and strata, giving figure to the topographic features and the endless variety and beauty of the topographic landscape. ”

“ The constant process of discharge from the water results in a constant process of deposition upon the bottom. It is in this manner that causation is continuous, and such a causation is a double process. A serial force is a process. In energy the work done by force is proportional to the time in which the force acts, but in the process this law does not necessarily obtain, for cause is not wholly a question of force but it is also a question of form and kind. ”

“ With this hypothesis another is associated, namely, that the centrosphere of the earth is metallic, for which no vestige of inductive evidence has yet appeared; and the stupendous fact remains that the centrosphere has more than twice the density of the crust. All eruptive rocks which come into the purview of science are found to have an average constitution which is about the same as that of the sedimentary rocks. It is found by experiment in the industrial arts that under pressure metallic and other substances flow ”

“ Great regions of country are at one time submarine, and at another subaërial. These oscillations of upheaval and subsidence are oft-repeated in geological history, and the swing of oscillation seems to have been in some regions tens or scores of thousands of feet where they reach the maximum, and to be only tens or scores of feet at the minimum, so that the surface of the earth, in so far as it has been studied geologically, is found to give evidence of oscillations of level varying in these quantities. ”

“ The ether evaporates the water, the wind carries it about and fills the air with dust, and the dust and vapor again fall to the earth as rain, and the falling becomes a process of disintegration in part, but mainly an agency for the transportation of material of the rocky cellate by sheets of water into streams and by streams into the larger bodies. Then gravity acts as a process, throwing the load of transportation to the bottom in assorted layers. ”

“ When inclined rocks are studied they seem to have been stretched, as evidenced in the elongation of particles transverse to the strike, and they seem further to have been stretched by the opening of fissures and joints. Altogether it may be affirmed that displacement does not teach the doctrine of a contracting earth, or, if that statement is too strong, it does not give evidence of a sufficient contraction necessary to the hypothesis, and it also fails to explain the concomitant phenomena. ”

“ It may be that there is a zone of matter beneath the structural rock and overlying the metallic nucleus which is penetrated by heat, now here, now there, and only these molten rocks are extravasated; or it may be that the solid state is limited by heat in one direction and by pressure in the other in such manner that all rocks flow under great pressure as do the metals. ”

“ Thus we see that in the processes that go on in the crust of the earth new kinds of substances are developed and new kinds of formations produced, and the chemist finds these substances to be arranged in series, and the geologist finds that sedimentary formations are arranged in series. ”

“ Wind waves and tidal waves are forever beating the lands and undermining the cliffs and distributing the materials beneath the sea. Then atmospheric agencies disintegrate the rocks and the rains wash the sands into the streams, which carry them into the lakes and into the sea. By many cognate processes the lands are worn down and the sea bottoms built up; the amount of detritus thus accumulated in zones about the meandering shores is great, so that in regions of maximum activity formations are accumulated thousands of feet in thickness. ”

“ The ethereal processes change hourly and daily with the longitude, and vary with the latitude. The winds blow and are calm; evaporation goes on until critical conditions are reached when storms fall; floods are also variable, and floods produce effects in geometrical ratio. The pressures of formations have their accelerations intermittent, so that stresses are revealed by earthquakes, and the fractures caused by earthquakes produce the channels for eruption, and add to pressures and stresses.
There is a change in hydrostatic pressure of such importance that it must not be neglected. ”

“ As the upper and lower surface of the crust is approached the rate of change in the substances is increased until these surfaces are reached. At the upper surface the disintegrated rocks form an overplacement of soils which undergo such chemical reaction that the substances of vegetal life are produced. ”

“ The theory of a metallic centrosphere seems adequately to account for the trans- solid state, as the metals are found to flow under pressure; but the molten material which from time to time is brought to the surface from the interior of the earth never reveals this metallic constitution. ”

“ Finally, there is now abundant geologic evidence to show that the faulting near the surface appears as flexure at greater depths, and finally that flexure appears as molecular readjustment at still greater depths, expressed in slaty structure where the particles of the rocks are rearranged in parallel planes.
The metals of the normal condition have great density, but in a pure condition are found only in exceedingly minute quantities; all the other rocks have a small density. ”

“ Great volcanic cones are often formed by the piles of scoria and ashes which are extravasated, and the ashes themselves when highly comminuted are drifted by the wind, sometimes far away from the locus of eruption. ”

“ The winds contribute to the material which falls into the sea; plant life also furnishes its quota; accumulations of vegetation are ultimately consolidated among the formations as beds of coal; and animal life adds to the marine formations, for corals, shells, and bones are all brought to be buried in the sand, and often extensive formations of calcareous matter are thus produced. ”

“ The aqueous envelope covers the rocky crust over about three-fourths of its surface, and has an average depth of about twelve thousand feet, though in extreme cases the bottom of the sea is more than five miles below its surface, while in some few cases mountains rise to more than five miles above the level of the sea. It is certain that we are now able to study rocks which were deposited at depths much greater than that of the mean depth of the ocean, and there are many cases where rocks found on the summits of high mountains are known to have been deposited at great depths beneath the sea. ”

“ Again, on the streams of great floods, great blocks are loaded, and as these blocks become larger they are the more efficient as hammers in the corrasion of stream channels both vertically and laterally; so that glaciers load themselves with rocks and become the agencies of corrasion by which valleys are carved. ”

“ Sometimes upheaval is by anticlinal flexure, where the rocks are lifted along a line of upheaval and caused to dip away on either side in gentle or abrupt slopes which are sometimes beautifully curved; but such an upheaval often seems to be accompanied by a subsidence on the flanks. Symmetrical anticlinal flexures are not very common, but often one side slopes gently while the other is abruptly deflected. ”

“ Blocks formed in this manner often careen upon their edges, so that the strata may become vertically disposed or quite overturned where the lower formed strata are found on top. Between careened blocks and flexed blocks no line of demarcation can be drawn: the same block in different parts of its course may be bent or broken, and the flexed blocks themselves be quite overturned. The rocks which are upheaved or depressed by faulting and flexing, one or both, are always found to be ruptured in line of the faults or flexures, and also transversely to them. ”

“ Contraction does not seem to be an explanation of all or even the chief phenomena which we have briefly set forth. When this hypothesis was considered, flexion seemed to be the chief method of displacement ”