Alluvium

“ That ere long, now that curiosity has been so much excited on this subject, some human remains will be detected in the older alluvium of European valleys, I confidently expect. ”

“ Then some great storm comes, and a liquid avalanche descends from the mountains where their sources lie, covers and ravages the plain, turning over the ancient alluviums, stirring up and mixing the old and new materials, and carrying farther each time the débris it has torn up on its passage. ”

“ The natives of these countries had gathered it from the beds of mountain-torrents, or in the alluvium of the valleys, after the annual rains had washed it down, freeing it, in the transit, from its associate minerals and impurities ”

“ It is evident from the foregoing remarks, that while even the smallest stream may make deposits of alluvial character it is in the flood-plains and deltas of large rivers that the great alluvial deposits are to be found. The finer material constituting alluvium, often described as “silt,” is sand and mud. Although it may be exceedingly fine-grained, there is usually very little clay in alluvium. The larger materials include gravel of all degrees of coarseness; carbonaceous matter is often an important element. The amount of solid matter borne by large streams is enormous ”

“ Much of the way it runs through a comparatively rainless region in summer, and the last few hundred miles it ploughs its course along through a sandy alluvium, where its channel is constantly shifting, and sand-bars everywhere prevail. ”

“ Through the whole series of rocks, six miles in thickness, we find similar remains, even increasing in numbers as we ascend; but it is not till we reach the very highest stratum, the mere superficial coat of alluvium, that we find the remains of man. The vast multitudes, then, of organized beings that lie entombed in rocks below alluvium, must [Pg 74] have yielded to death long before man received his sentence, Dust thou art, and to dust shalt thou return. Will any one maintain that none of these animals preceded man in the period of their existence? ”

“ Their banks are subject to overflow, and frequently have a clayey subsoil, presenting an obstacle to percolation—thus upon the river's receding into its ordinary channel its banks remain damp below the surface, and disease is generated by the sun's agency. A like process annually takes place in the extensive plains and table-lands 'formed of alluvium washed down from mountain-ranges during the lapse of centuries, and having few actual marshes. ”

“ When the courses of engulfed rivers are thus liable to change, from time to time, by alterations in the levels of a country, and by the rending and shattering of mountain masses, we must suppose that the dens of wild beasts will sometimes be inundated by subterranean floods, and their carcasses buried under heaps of alluvium. The bones, moreover, of individuals which have died in the recesses of caves, or of animals which have been carried in for prey, may be drifted along, and mixed up with mud, sand, and fragments of rocks, so as to form osseous breccias. ”

“ Thus a fall in the gradient at any point in the course of a stream; any snag, projection or dam, impeding the current; the reduced velocity caused by the overflowing of streams in flood and the dissipation of their energy where they enter a lake or the sea, are all contributing causes to alluviation, or the deposition of stream-borne sediment. ”

“ It was a battle between the heavens and the earth,—the stream of molten rock, blinding [Pg 57] hot from the caverns beneath the earth’s crust, meeting the sweet cool waters from the clouds that troop about the mountains or hide their tops in mist and snow. The life-giving flood prevailed over that which brought only defacement and death. The sullen lava flux settled, shrank, and hardened at last, fitting into the granite gorges as melted lead fits the mould into which it is poured. ”

“ Imagine a great mass of snow and ice descending between the clefts of mountains to lower levels. As it slips slowly down its valley, like a very slow river—slower than a river of thickest mud or pitch or lava would be—earth, sand, mud, gravel, boulders, and masses of rock sometimes are washed down on its surface from the slopes on either side. Avalanches will occasionally bring other contributions. ”

“ Superposed on all this is so-called physiography, the science of falling materials and water, the rotting of the lands, and the accumulation of debris. A net of rivers over ground and under ground is what stands out, and the living river pattern has changed incessantly through the ages. But through and over it is a moving process of the ages, kinetic, alive with glaciers, hot springs, underground heat or surface cold, soaking rains and rushing storms, earthquake and uplift, fault motions and sinkings. ”

“ The mountain heights which bound it, being composed for the most part of schist, mica slate, and talcose slate, large masses become detached in winter—split off by the freezing of the water behind them—when they descend, on the coming of thaw, in terrible avalanches of stone and mud. Sometimes the masses are such as to dam up the river and form temporary lakes, until the accumulation of force behind bursts the barrier, and a furious flood rushes down the valley. ”

“ The effect of this lifting was to raise the mouths of the two rivers, and throw back their waters on the city, and this overflow added its share of mud, ashes, and vegetable matter. Nor must we omit the canals filled up, the sewers choked, the aqueducts shattered by the earthquake, and pouring their contents into the valley. By degrees, as the mud settled in the streets, the courts, rooms, and dwellings, the level of the water rose, new deposits gathered; the ashes falling in dense masses from the sky, grew saturated, and increased the rising heaps. ”

“ Whatever lies in the path of the flood is swept from the face of the earth. The mountains, assailed in a moment with the ferocity of a hundred storms, are ripped and torn like hills of clay. The frosted scale of the granite, the desperate root of the cedar, the poised nest of the eagle, the clutch of the crannied vine, the split and start of the mountainside, are all as one before the June thaw. ”

“ When the storm reached the low point dividing the river, the house shook in the wind, and the rain pattered loudly on the palm-leaf roof, the thunder spoke in one prolonged roll, and the incessant lightning disclosed a turmoil of leaping waters, driving logs, and the big trees bending before a brutal and merciless force.
Undisturbed by the nightly event of the rainy monsoon, the father slept quietly, oblivious alike of his hopes, his misfortunes, his friends, and his enemies ”

“ The water of the downpour would have rushed by us, muddy with the spoils of the rocks, coming together into torrents, cutting deep gorges and canyons as they hurried past to deposit their sediment in the earliest seas. Through the clouds we should have glimpsed a great sun moving visibly across the sky, and in its wake and in the wake of the moon would have come a diurnal tide of earthquake and upheaval. ”

“ Soon afterwards, the rain descended in torrents; gusts of wind, such are only experienced under the tropics, blew down houses, uprooted trees, and drove the waves mountain high, which threatened at each moment to overwhelm us with destruction. ”

“ But when ye have journeyed with much toil and no little peril over the mountain-necks, for by the gorge of the river, as aforesaid, no man may go, and have come out of the mountains once more, then again ye have the flood before you, cleaving a great waste of rocks mingled with sand, where groweth neither tree nor bush nor grass ”

“ It seems as if heavy hailstones were rattling down, but they are only rain-drops which bear with them in falling the up-whirled dust and sand. Now the flashes are seen. One follows so quickly upon another that we are forced to close our dazzled, well-nigh blinded, eyes, and to follow the storm only by listening to the uninterrupted roll of the thunder. The downpour becomes a cloud-burst; from the hills the water rushes down everywhere in streams; in the hollows it forms lakes; in the valleys there are rivers in flood. ”

“ Among these revolutions of nature, we never reckon common inundations, such as take place at present from water overflowing its boundaries, though these also may produce devastation whose effects remain visible for an hundred years. But, in mountainous districts, another kind of aqueous eruption makes its appearance, and may be classed along with the traditions of a deluge. We very frequently, for instance, observe the valleys of high mountains forming a range of basins separated from one another by shorter or longer defiles, and opening through the last defile into a wider valley, or a marsh. ”

“ An Extraordinary Storm And Flood Glorious as are these rocks and waters arrayed in storm robes, or chanting rejoicing in every-day dress, they are still more glorious when rare weather conditions meet to make them sing with floods. Only once during all the years I have lived in the Valley have I seen it in full flood bloom. ”

“ The rain which falls on plains or gently undulating surfaces, although after a while it dries up, yet to some degree aids in levelling the land, partly by washing down particles of earth, however slowly, to lower levels, partly by soaking the earth and preparing a thin stratum of its upper surface to be converted into dust, and blown away by the wind. But it is when very heavy storms occur that the levelling action of rain over widely extending regions can be most readily recognized. ”

“ When the wind with its flood of rain comes toward us as we crouch by the wall we are beaten and drenched and buffeted and driven hard against that cold, blue surface. And the ragged edges of the rocks make bruises on our foreheads. ”

“ The flood, the tornado, the volcano, were all evidences of the displeasure of heaven, and the sinfulness of man. The blight that withered, the frost that blackened, the earthquake that devoured, were the messengers of the Creator. ”

“ C'est parmi ces tempêtes que naît la vie.’ ... ‘Les eaux, de nouveau tranquillisées, mais dont le contenu a changé, déposent des couches moins épaisses et plus variées, où les débris des corps vivans s'accumulent successivement dans un ordre non moins fixe que celui des roches qui les contiennent. Enfin, la dernière retraite des eaux répand sur le continent d'immenses alluvions de matières meubles, premiers sièges de la végétation, de la culture et de la sociabilité.’ Eloge de Werner, in Cuvier, Recueil des Elogés Historiques, vol. ”

“ Forests and buildings in its path were leveled as by a tornado, wood was charred and set on fire by the incandescent fragments, all vegetation was destroyed, and to breathe the steam and hot, suffocating dust of the cloud was death to every living creature. ”

“ The breeze that has been blowing from the lowlands dies away, and far and near the mighty host of trees baptized in the purple flood stand hushed and thoughtful, awaiting the sun’s blessing and farewell,—as impressive a ceremony as if it were never to rise again. When the daylight fades, the night breeze from the snowy summits begins to blow, and the trees, waving and rustling beneath the stars, breathe free again. ”

“ I turn upon my pillow and again
Compose myself for slumber.
Let them sweep;
I once survived great floods, and do not fear,
Though ominous planets congregate, and seem
To foretell strange disasters. ”

“ Such catastrophes roll mountains and masses like a brook does its little pebbles, and throw up the water released from confinement in the cavities of heights which attract and collect it. A flood of liquid earth rolled then far and wide from the mountains without order and with numerous arms, but conformably to nature, the heavy particles sank. ”

“ Only the east wind, calculated to reduce the waters, is blowing, and gradually it takes away the stagnant flood. Other means also are effective; the ocean no longer hurls its waves upon the land, but takes back the waters which it had spewed forth, and the floodgates of heaven are closed up. ”

“ As there are waters under the earth, so AEtna, Vesuvius, and other volcanoes, proclaim to the world that there are subterranean fires too; and fire often falls from heaven, many desolations are made by lightning; so that when the time predetermined comes, between these two fires the earth and all the works therein shall be burnt up; as the flood was brought upon the old world out of the fountains of the great deep, and through the windows of heaven. ”

“ This formation has, doubtless, been produced on the bottom of a troubled sea, where the crust has been exposed to violent action—much of it comminuted and broken into fragments, rolled and fashioned into nodules, large portions of it torn up, but retaining their continuity for a space—when the molten flood has poured from below, and diffusing itself through the mass, the whole, after successive eruptions, has been lifted to its present elevation. ”

“ In consequence of the gradual rise of the river's bed, the annual flood is constantly spreading over a wider area, and the alluvial soil encroaches on the desert, covering, to the depth of six or seven feet, the base of statues and temples which the waters never reached 3000 years ago. ”

“ The ground sounds hollow underfoot, and the awful subterranean thunder shakes one’s mind as the ground is shaken, especially at night in the pale moonlight, or when the sky is overcast with storm-clouds. In the solemn gloom, the geysers, dimly visible, look like monstrous dancing ghosts, and their wild songs and the earthquake thunder replying to the storms overhead seem doubly terrible, as if divine government were at an end. ”