Mudstone

“ On a sloping tract of ground in a slight hollow is a small lake of liquid mud, with patches of blue, red, or white, and in many places boiling and bubbling most furiously. All around on the indurated clay are small wells and craters full of boiling mud. These seem to be forming continually, a small hole appearing first, which emits jets of steam and boiling mud, which upon hardening, forms a little cone with a crater in the middle. The ground for some distance is very unsafe, as it is evidently liquid at a small depth, and bends with pressure like thin ice. ”

“ This morning he told us, that the debris of the hills which accumulate in alluvial districts usually continue in the loose form of gravel or sand, or mud, or clay, in which they were deposited. “Their visible transformation,” he said, “into stone is of rare occurrence; in some circumstances, however, especially on the sea coast, we may perceive the consolidation of the sand and gravel into thin strata. If a stream, impregnated with oxide of iron, should empty itself on the beach, it acts as a cement, and the process goes on rapidly. ”

“ From our very feet a precipitous mud slope falls away for half a mile or more till it reaches the level. At our right, still below us, rises a mud wall a mile long, also sloping down to the level, and behind it is evidently the crater; but before us, for five miles in a straight line, and on each side nearly as far, is a sea of congealed mud, broken up into ripples and waves and great billows, and bearing upon its bosom a thousand huge boulders, weighing hundreds of tons apiece. ”

“ When a bed is thin, the clean white mud is permitted to rest, as in this case, upon a slab of the coarser slate in contact with it: when the bed is thick, it is cut into slices which are cemented to pieces of ordinary slate, and thus rendered stronger. The mud thus deposited sometimes in layers is, as might be expected, often rolled up into nodular masses, carried forward, and deposited by the rivers from which the slate-mud has subsided. Here, indeed, are such nodules enclosed in sandstone. ”

“ Mudpots form in places where the upflowing thermal fluids have chemically decomposed the surface rocks to form 83 clay. Such small amounts of water are involved, however, that the surface discharge is not great enough to flush the clay out of the spring. Caldrons of mud of all consistencies result, from the very thin soupy material in many mudpots to the almost hard-baked material in the less active features. ”

“ The extraordinary resistance of the mudlump clay, when once consolidated in the channel banks, to erosion by water, serves, together with the somewhat similar characteristics of the underlying Port Hudson clay, to explain the exceptional form of the lower delta of the Mississippi.
I should add that a microscopic, physical and chemical examination of the mudlump mud, and of the clay from the banks of the Passes, bear precisely the biological characteristics to be expected under the conditions outlined. There is an intermixture of fresh-water and brackish marine organisms ”

“ Every little rill that flows down the mountain side is charged with finely-powdered sediment which it is ever wearing away from the surface of its own bed. Every great stream, besides the immense quantities of mud and sand which in times of flood it carries along in its turbulent course, has its channel strewn over with pebbles at which it never ceases to work, rounding off the angles and polishing the surfaces; and these pebbles, what are they but the fragments of old rocks and the elements of new,—the rubble-stone of Nature’s edifice on its way from the quarry to the building? ”

“ Taking the existence of this semi-fluid mud-stratum resting upon the Port Hudson clay and buried by the delta sands and silts throughout the lower delta, for granted, the mechanism of mudlump upheaval at once suggests itself; for the rapid advance of the heavy and extended load of river sands and silts of the bar over the mud stratum would not permit the escape of the slow-moving mud to seaward. ”

“ It is by no steady and rapid movement that waste is swept from the shore to its final resting place. Day after day and century after century the grains of sand and particles of mud are shifted to and fro, winnowed and spread in layers, which are destroyed and rebuilt again and again before they are buried safe from further disturbance.
These processes which are hidden from the eye are among the most important of those with which our science has to do; for it is they which have given shape to by far the largest part of the stratified rocks of which the land is made. ”

“ First, they soften the ground they flow over and make mud. The mud mixes with the water and goes along with it. Stones are loosened and rolled along, too. Fill a big gold-fish bowl with this muddy water at- the mouth of the brook, and let it stand awhile to settle.
Stones from same cliff after they have been worn and rounded by rolling about in the current of the river. Through the glass you see clear water at the top, then mud, then sand, then gravel. The gravel falls the lowest because it is the heaviest. ”

“ The sediment with which the waters are charged is extremely fine, being derived from the destruction of cliffs of red sandstone and shale, belonging chiefly to the coal measures. On the borders of even the smallest estuaries communicating with a bay, in which the tides rise sixty feet and upwards, large areas are laid dry for nearly a fortnight between the spring and neap tides, and the mud is then baked in summer by a hot sun, so that it becomes solidified and traversed by cracks caused by shrinkage. ”

“ The parts of the shore most rapidly corroded by the sea, are those composed of sand, chalk, and clay, while those composed of the harder kinds of sandstone or of granite, have been but little wasted away, so that they project and form the headlands, while in many cases deposits of mud have extended them. There are many other causes which determine the elevation or depression of the land, besides the action of the sea and earthquakes, such as winds, frosts, &c. ”

“ Gradually from bottom to top the coarseness diminishes, and near the upper surface of each layer we have a mass of comparatively fine clean mud. Sometimes this fine mud forms distinct layers in a mass of slate-rock, and it is the mud thus consolidated from which are derived the German razor-stones, so much prized for the sharpening of surgical instruments. ”

“ The rains had softened the trail, until it was of the consistency of very stiff mud. In 58 this mud the first mule had left his tracks. The next mule trod carefully in the first mule’s footsteps; and all subsequent mules did likewise. The consequence was a succession of narrow, deep holes in the clay, into which an animal’s leg sank halfway to the shoulder. No power on earth, I firmly believe, could have induced those mules to step anywhere else. ”

“ The mud which constitutes the bottom of the lake is a smooth, even, plastic clay, of unknown depth. It has been bored through thirty feet without showing change in its structure. The upper portion, for four and a half to five feet, holds unnumbered crystals; at that depth they suddenly and abruptly cease. Abundant explorations demonstrated that none were to be found any lower, and the daily working came to recognize the fact as established. The mud below that was saturated with the salts of soda, such as held by the water of the lake, but no distinct crystals existed. ”

“ The mud which is spread on the permeable bottom does not soil the scoria, but leaves it perfectly clean, while the water flows clear from the end of the drains. After two or three days, according to the weather, the mud will appear cracked at some points, and finally over the whole surface. After a week it will have acquired consistency enough to be cut with a shovel. A cart is then brought into the basin, and after a few hours it is emptied and is ready to receive a new charge of mud. ”

“ Slowly, perhaps, she would sink that mud so deep, and cover it up with so many fresh beds of mud, or sand, or lime, that under the heavy weight, and perhaps, too, under the heat of the inside of the earth, that Mud would slowly change to hard Slate Rock; and ages after, it may be, Madam How might melt that Slate Rock once more, and blast it out; and then through the mouth of a volcano the little grain of mineral might rise into the open air again to make fresh soil, as it had done thousands of years before. For Madam How can manufacture many different things out of the same materials. ”

“ In the very centre of this there was a huge mark—an ill-defined blotch, deep, broad and irregular, as if a great boulder had fallen upon it. No loose stone lay near, however, nor was there anything to account for the impression. It was far too large to be caused by any possible animal, and besides, there was only the one, and the patch of mud was of such a size that no reasonable stride could have covered it. ”

“ It is very true that many of them in going up could not be seen, on account of the dark smoak; but, when they returned from the smoaky heat, they shewed plainly where they had been, by their strong smell of fetid sulphur, just like stones that have been thrown out of a mortar, and have passed through the smoak of inflamed gunpowder. The mud was of the colour of ashes, and at first very liquid, then by degrees less so; and in such quantities, that in less than twelve hours, with the help of the abovementioned stones, a mountain was raised of a thousand paces in height. ”

“ By the time the Rhone has reached Arles all its gravel has been champed up and reduced to impalpable mud. That blue crystalline flood that gushed from the Lake of Leman, unsullied by a particle of earth, is now a river of brown mud—thick as pea-soup, and as nutritious. The stones that would have killed all vegetation have been pounded into a condition so attenuated, that they form rich alluvial matter. The river now seeks to deposit all this mud. ”

“ Muds, sands, grits and conglomerates are the predominant types. In Scotland, North America and Canada important deposits of limestone occur and subordinate limestones are found in the Cambrian of central Europe.
In some regions, notably in the Baltic province and in parts of the United States, the rocks still retain their original horizontality of deposition, the muds are scarcely indurated and the sands are still incoherent; but in most parts of the world they bear abundant evidence of the many movements and stresses to which they have been exposed through so enormous a period of time. ”

“ The earth (or mud) was extremely hard and tenacious, and the stones embedded in it were extricated with considerable difficulty. The mud adhered very firmly to the stones that were got out, but it was readily washed away in a little stream near at hand. In a few minutes I extracted fragments of syenite, mica-schist, several kinds of limestone and conglomerates, and some fossil plants characteristic of carboniferous strata. Most of the fragments were covered with scratches, which told that they had traveled underneath a glacier. ”

“ There are, as all know, mud-holes that are but blotchy remnants of man’s interference—mere accidents, as it were, which do not concern us; and also those deeper scars where the fair face of the landscape has been wounded severely, as when the ice-gorged river bursts its proper bounds, leaving a shallow pool in my pasture meadow: such as these are never beneath the notice of a contemplative rambler. The truth is, in the valley of the Delaware the average mud-hole is eminently respectable. Giving the matter a sober second thought, one will see that mud is not necessarily offensive. ”

“ This is humorously named by Kate the Rotomahana Hotel, and is the place where lunch is usually devoured.
Up a steep, muddy hill now, and at the top we emerge on the mud flat, where many boiling mudholes repeat the phenomena we have already seen, only substituting liquid boiling mud instead of water. We look down, and see a seething mass of molten mud in incessant motion. It rises up in great circling domes and plastic cupolas, which seethe, and expand, and swell, and then break with a lazy, hissing, escape of steam ”

“ Such ground may repose at a 4 to 1 TO 8 to 1 slope, because its crust has become caked or case-hardened, yet when it is broken it may become, upon being exposed, simply fluid mud. To prevent clay soil weathering upon the surface, a layer of gravel 1 foot or so in thickness has been placed upon it, the idea being that it is not only a protection, but the weight of the covering upon the clay will cause the water to be pressed out from the soil into the gravel through which it can percolate to the drains. ”

“ They seldom have any visible outlet, but are in constant agitation, with a sound which varies with the consistency of the contents; several give off a suppressed thud as the gases burst their way through the stiff mortar. Sometimes the mortar is as white as snow; sometimes brown, or tinged with a variety of vivid colors. One mud spring, located in the woods near a small lake, northeast of the Cavern, has a basin thirty by forty feet, with sides fifteen feet high. It is in constant action, frequently hurling the mud outside of the rim. ”

“ If the pit be previously secured to a certain depth, the tub is made to pass within the cradling, and is lowered down with tackles till it rests fair among the soft alluvium. It is then loaded with iron weights at top, to cause it to sink down progressively as the mud is removed from its interior. Should a single tub not reach the solid rock (sandstone or basalt) , then another of like construction is set on, and the gravitating force is transferred to the top. Fig. 827. represents a bed of quicksand resting on a bed of impervious clay, that immediately covers the rock. A is the finished shaft ”