Siliceous sentence example
The surface soil is clay in which are embedded fragments of siliceous sandstone, used for millstones and constructional purposes; the subsoil is limestone.
The siliceous Claiborne (or Tallahatta Buhrstone) formation lies south-westward from the last-named in a strip 10-30 m.
The Jackson formation south-west of the Lisbon beds, is made up chiefly of grey calcareous clay marls, bluish lignitic clays, green-sand and grey siliceous sands.
About half of the varieties of forest trees in the United States are found, and 1 Almost everywhere limestone is the underlying rock, but siliceous sands, brought out by the Atlantic rivers to the N.E., are carried the whole length of the Florida coast by marine action.
Muscovite and biotite are commonly found in siliceous rocks, whilst phlogopite is characteristic of calcareous rocks.Advertisement
Aluminium, when pure and kept out of contact with siliceous matter, is only oxidized at a white heat, and then very slowly, into alumina, Al 2 O 3.
It includes chalky limestones, siliceous earths, red clay, and, at the top, a layer of mudstone composed mainly of volcanic dust.
The limestones contain Globigerina and other Foraminifera, the siliceous beds are made of Radiolaria, sponge spicules and diatoms, while the red clay closely resembles the red clay of the deepest parts of the oceans.
These rocks, which include some highly siliceous lavas, form part of the Eocene series that is so conspicuously displayed above Carlingford in Co.
A particularly fine-grained mud is formed on the low coasts of the eastern border of the North Sea by a mixture of the finest sediment carried down by the slow-running rivers with the calcareous or siliceous remains of plankton.Advertisement
To this inconceivably slowly-growing deposit of inorganic material over the ocean floor there is added an overwhelmingly more rapid contribution of the remains of calcareous and siliceous planktonic and benthonic organisms, which tend to bury the slower accumulating material under a blanket of globigerina, pteropod, diatom or radiolarian ooze.
It is a remarkable geographical fact that on the rises and in the basins of moderate depth of the open ocean the organic oozes preponderate, but in the abysmal depressions below 2500 or 3000 fathoms, whether these lie in the middle or near the edges of the great ocean spaces, there is found only the red clay, with a minimum of calcium carbonate, though sometimes with a considerable admixture of the siliceous remains of radiolarians.
It has been found sporadically near the Aleutian Islands, between the Philippines and Marianne Islands and to the south of the Galapagos group. It is made up to a large extent of the siliceous frustules of diatoms. It is usually yellowish-grey and often straw-coloured when wet, though when dried it becomes white and mealy.
Radiolarian ooze was recognized as a distinct deposit and named by Sir ' John Murray on the " Challenger " expedition, but it may be viewed as red clay with an exceptionally large proportion of siliceous organic remains, especially those of the radiolarians which form part of the pelagic plankton.
Systematic quarrying of siliceous crystalline rocks in New England began at Quincy in about 1820.Advertisement
About nine-tenths of the gold was got from dry or siliceous ores and about 8% from placer mines; about twothirds of the silver from dry or siliceous ores, about two-ninths from copper ores, and most of the other ninth from lead ores.
Rhaetic beds (Infra Lias), consisting of dolomites and siliceous limestones, have been recognized at Saida.
It contains much volcanic material, and great bodies of siliceous shale, locally estimated at 4000 ft.
North of the mineral region is the "Cereal Belt," embracing the Tennessee Valley and the counties beyond, whose richest soils are the red clays and dark loams of the river valley; north of which are less fertile soils, produced by siliceous and sandstone formations.
In the pine forests of the Alps the prevailing species are the common spruce and the silver fir; on siliceous soil the larch flourishes, and surpasses every other European species in height.Advertisement
The more argillaceous and the less siliceous the soil the more readily can balls of earth be retained about the roots.
They extend back beyond the Carboniferous, where they occur as hyphae, &c., preserved in the fossil woods, but the best specimens are probably those in amber and in siliceous petrifactions of more recent origin.
When the former is used it is roasted with calcium sulphate or alkali waste to form a matte which is then blown in a Bessemer converter or heated in a reverberatory furnace with a siliceous flux with the object of forming a rich nickel sulphide.
The process adopted for the Canadian ores, which are poor in copper and nickel, consists in a preliminary roasting in heaps and smelting in a blast furnace in order to obtain a matte, which is then further smelted with a siliceous flux for a rich matte.
The coarse-metal is now smelted, with coke and siliceous fluxes (in order to slag off the iron), and the product, consisting of an impure copper sulphide, is variously known as " blue-metal," when more or less iron is still present, " pimplemetal," when free copper and more or less copper oxide is present, or " fine " or " white-metal," which is a fairly pure copper sulphide, containing about 75% of the metal.Advertisement
Antimony, however, occurs chiefly as the sulphide, stibnite; to a much smaller extent it occurs in combination with other metallic sulphides in the minerals wolfsbergite, boulangerite, bournonite, pyrargyrite, &c. For the preparation of metallic antimony the crude stibnite is first liquated, to free it from earthy and siliceous matter, and is then roasted in order to convert it into oxide.
This substance, which has been found to be a purely siliceous concretion, is possessed of peculiar optical properties.
The outer cuticle of Oriental species is so hard that it forms a sharp and durable cutting edge, and it is so siliceous that it can be used as a whetstone.
The hard ore is siliceous, and fine crystallized specimens occur in association with smoky quartz.
In 1908 the richest producers of gold were Salt Lake (60,872.63 oz.), Juab (58,679.17 oz.) and Tooele (41,969.96 oz.) counties, which produced about nine-tenths of the total for the state; in Salt Lake and Juab counties the principal source was copper ore, but in Tooele county almost all the gold was from siliceous ores.Advertisement
The manufactures of Quincy were long unimportant, with the exception of "Quincy granite,'" which was first quarried in 1825,-this being the first "systematic siliceous crystalline rock quarrying" in New England-and of which the output in the form of tombstones and monuments in 1905 was valued at $2,018,198, and in the form of "marble and stone work" was valued at $364,924.
Where the flints lie the chalk must have been dissolved away; we have in fact a kind of metasomatic replacement in which a siliceous rock has slowly replaced a calcareous one.
Some cherts contain tests of radiolaria, and correspond fairly closely to the siliceous radiolarian oozes which are gathering at the present day at the bottom of some of the deepest parts of the oceans.
Some siliceous schists of the Permian age were discovered in 1908 in the valley of the Sakameira, south of the Onilahy, or Augustine river.
At Little Bytham a very hard brick, called adamantine clinker, is made of the siliceous clay that the Romans used for similar works.Advertisement
The marine Tertiary accumulations commence with those that are referable to the Eocene series, consisting of nummulitic limestones, marls and siliceous sandstones.
Ganister, a slightly plastic siliceous sand, is similarly used for the lining of Bessemer steel converters; it is found in the neighbourhood of Sheffield.
In an oxidizing atmosphere it is indifferent to silica, and therefore siliceous bricks containing a considerable proportion of ferric oxide, when used in flues of boilers, brewers' coppers, &c. and similar situations, are perfectly fire-resisting so long as the heated gas contains a large proportion of unconsumed air.
The type of coarse aggregate used included normal-weight calcareous and siliceous, and lightweight.
Ben Nevis Highland Ben Nevis is representative of high altitude siliceous scree in the northwest Scottish Highlands.Advertisement
The presence of calcareous bands within otherwise mainly siliceous rocks often brings the two types together on the same rock outcrop.
In many parts, particularly in the eastern basin, a calcareous or siliceous crust, from half an inch to three inches in thickness, is met with; and Natterer suggested that the formation of this crust may be due to the production of carbonate of ammonium where deposits containing organic matter are undergoing oxidation, and the consequent precipitation of carbonate of lime and other substances from the waters nearer the surface.
Travers has suggested that it may explain the liberation of helium from minerals by heat, the gas being enabled to permeate the siliceous materials in which it is enclosed.
The lower and middle divisions of the Jurassic, composed of massive limestones more or less siliceous and overlain by the marls amd highly fossiliferous limestones of the Upper Lias, play an important part in the constitution of the chief mountains of the Tell.
This collegue is actually working on biogenic abrasion of siliceous substrates.Advertisement
Lake District High Fells Cumbria Lake District High Fells represent high-altitude siliceous slopes with chasmophytic vegetation in northern England.
Siliceous remains include long cells with a single line of stomata.
The habitat type is developed on massive outcrops of siliceous igneous rocks with crags up to very high altitude.
Concentrations of siliceous plant remains may be higher in some areas not sampled for the Leverhulme Project, based on observations in the field.
The springs are principally alkaline, alkaline and siliceous, acidic, or acidic and hepatic (sulphurous).Advertisement
His maps on the distribution of carbonates, siliceous deposits and manganese nodules form the basis of understanding oceanic sedimentology.