Pure kaolin clay is white and impalpable, like China clay; but pure clays are the exception.
Clays are sometimes calcareous, from the presence of shells and shell-fragments or of pulverized limestone.
A similar change takes place with the micas, augite, and hornblende; but these species, being usually rich in iron, make clays which are much darker colored than those derived from feldspars.
But here are the very first species of mollusca in the more recent clays unchanged, and here are the same little animals that floored so much territory in the bygone with chalk.
Inarticulate or molluscan life is seen in a sub-fossil condition in the Post Pliocene clays of Canada.
The demand for millions of years, in order to get old species out and new ones in, breaks down with the mollusk of the Pliocene in the clays of Canada.
But such a place is Glenn Spring, the chief spring along a dry draw that starts in the Chisos and cuts deeply through many-colored clays as it crosses the desert.
Glacial gravels, clays and loams cover a great deal of the whole area, and the Upper Chalk itself has been disturbed at Reed and Barley by the same agency.
The Reading beds consist of mottled and yellowclays and sands, the latter are frequently hardened into masses made up of pebbles in a siliceous cement, known locally as Hertfordshire puddingstone.
But we shall not stay to describe her disappointment, or the art of her mother in concealing it; nor shall we accompany Mrs. Falconer to town, to see how her designs upon the Clays or Petcalf prospered.
Notwithstanding the pains which Mrs. Falconer took to engage these Mr. Clays to accompany her, she could obtain only a promise that they would wait upon her, if possible, some time during the recess.
She expected the two Mr. Clays at Falconer-court the next day.
You will find that all your dinners and concerts will be just as much thrown away upon the two Clays as your balls and plays were upon Count Altenberg.
In stiffclays the potatoes are invariably watery and waxy, but in light sands and loams, they are tolerably dry and mealy.
For the bean, in particular, the climate appears too hot, and it is only to be obtained in the stiffest clays and the dampest situations.
The encaustic tile, strictly so-called, was decorated with patterns formed by different coloured clays inlaid in the tile and fired with it.
In clays also siliceous and calcareous concretions are often found.
Another type of concretion, very abundant in manyclays and shales, is the "septarian nodule.
In clayslarge crystals of gypsum, having the shape of an arrow-head, are occasionally found in some numbers.
In the Ardennes claysbearing pyrites and oolitic limonite are about 30 ft.
Clays and shales with ferruginous oolites represent the Callovian of Germany; while in Russia the deposits of this age are mainly argillaceous.
In France they are well exposed on the coast of Calvados between Trouville and Dives, where the marls and clays are 200 ft.
These clays and sands are very thick in the south-east of the county, but everywhere the chalk is below them if we go deep enough.
It is also of interest to observe that the river has turned away from the soft clays which form the ground south and east of Reading, and has cut a deep valley in the hard chalk from Wargrave onwards.
They consist of clays and sands, and were deposited in the bed of a great river.
At Hé sho ta tsí nan or Ojo del Pescado, fifteen miles east of Zuñi, clays of several varieties and color minerals are abundant.
A brown or reddish pigment used in both oil and water colors, obtained from certain natural clays variously colored by the oxides of iron and manganese.
The name is now applied to all porcelain clays which endure the fire without discoloration.
Our area lies in a part of east central Iowa where the stony clays deposited by ancient glaciers accumulated in long ridges and belts of upland rising many feet above the intervening undulating plains.
Upon these clays formed from the decaying rock rest stony clays in which clay, sand, and stones faceted as only glacier ice can facet, are mingled pell-mell together, as only glacier ice can mingle.
At the time when these sea clays were laid, eastern Iowa was under sea, but so near was the low lying land to the north and east that vast quantities of mud were brought in by its rivers forming deposits nearly 300 feet in thickness.
It covered the stiff intractable clays that would otherwise have been the only soils of the region.
The ice sheets of the glacial epoch plastered the county thick with the stony clays which they dragged along in their basal layers.
These sands repose upon the Upper Lias clays in the south and west of England.
Layers of lignite also accompany the inferiorclays and sands.
Layers of light brown and sometimes black lignite are interstratified with the clays and sands, and often irregularly diffused through them.
Next below are fresh-water and estuary marls and carbonaceous clays in the brackish-water portion of which are found abundantly Cerithium plicatum, Lam.
Sands and clays of Barton Cliff, Hants: Gres de Beauchamp, or Sables Moyens.
They consist of blue clays with some subordinate layers of lignite, and exhibit a richer flora than the overlying Newer Pliocene beds, and one receding farther from the existing vegetation of Europe.
Clays are compact soils, not only by reason of the fineness of their particles, but because the predominating alumina swells and becomes pasty when it is wet, and thus prevents the passage of water through them.
The Radiolarian clays of the Nicobar Islands are unfortunately very incompletely known both as regards their geological nature and their palaeontological composition.
A thorough systematic examination of these important Radiolarian clays is a pressing necessity, especially as they seem to be markedly different from those of the Mediterranean (from Aegina, Zante, &c.
Among the Radiolarian or Polycystine clays we include the firm, often plastic, formations, which contain a larger proportion of Radiolaria than of other organic remains.
In Germany the lower division consists mainly of grey clays and schieferletten with white, grey and brightly coloured sandstone and dolomitic limestone.
The Jurassic deposits consist of iron-clays and limestones, containing large caves.
Clays and marls with occasional limestones and sandstones represent the Kimeridgien of most of northern Europe, including Russia.
Ironstone is found in the Wadhurst Clay, a subdivision of the Hastings beds, clays and calcareous ironstone in the Ashdown sand, but the industry has long been discontinued.
I have not seen these actually attached, but they occur very abundantly in the under-clays of some erect forests of these plants at Horton Bluff, and are of the character of Stigmariæ (Figs.
But in some localities we have stratified clays with plant-remains later than the Glacial epoch, yet indicating that the great cold had not then entirely disappeared.
In the great interior plain of America there rests on the Cretaceous a series of claysand sandstones with beds of lignite, some of them eighteen feet in thickness.
In some of the under-clays the long, flattened rootlets are excessively abundant, and show the mark of a central vascular bundle.
The Stigmaria under-clays and the stumps of Sigillaria in the coal-roofs equally testify to the accumulation of coal by the growth of successive forests, more especially of Sigillariæ.
Similar remains occur in clays of like origin in the basin of the great lakes and in the West.
The botanical character of the flora of the Amboy clays will be seen from the following brief synopsis: "Algæ.
This fact appears also in the leaves and other organs of plants preserved in the nodules in the Pleistocene clays of the Ottawa, and in specimens of similar age found in various places in Britain and the continent of Europe.
In Canada, though fragments of the woody parts of plants occasionally occur in the marine clays and sands, there is only one locality which has afforded any considerable quantity of remains of their more perishable parts.
The macrospores collected by Mr. Thomas from the Chicago clays and shales conform closely to those of Kettle Point, and probably belong to the same species.
In New Jersey the Amboy clays are referred to the same age with the Dakota beds of the West.
Investigation of the clays and of the products of clays needed in Government works, as to their strength, durability, suitability as fire-resisting materials, and the methods of analyzing and testing clay products.
The study of the preliminary treatment of clays difficult to handle dry, has furnished useful information regarding the drying of such clays, and concerning the fire resistance of bricks made of soft, stiff, or dried clay of various densities.
The remaining room on the first floor is devoted to the drying of clays and clay wares.
In most of the tertiary clays there are small concretionary nodules, which contain more calcareous matter than the mass of clay around them.
In many of these cases, particularly in the clays and coal, the nodules have an organic nucleus, and, although concretionary, they retain the marks of stratification of the adjacent rocks.
It is at this time and under such circumstances that I believe the first formation of the Amazonian Valley, with the coarse, pebbly sand beneath, and the finely laminated clays above, to have been accumulated.
This principle, generally correct, is questioned when applied to peculiar clays only.
Peaty soils and strong clays are very absorbent of water, although not always the best for cultivation.
Certain clays are wet and beaten up into this consistency, to form the bottoms of ponds, and to tighten dams and reservoirs.
The cost of draining uniform clays should not exceed £3 per acre.
And in considering the "Drainage of Stiff Clays," we shall see that the most obstinate clays are usually so affected by the operation of drainage, that they crack, and so open passages for the water to the drains.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "clays" in a variety of sentences. We hope that you will now be able to make sentences using this word.
