Sandstones Sentence Examples

The Lower Tertiary consists largely of reddish sandstones resting upon the old rocks of the Cordillera and of the Sierras.

The latest Cretaceous is the Ripley formation, which lies west of the northern part of the last-named, and, about Scooba, in a small strip, the most southerly of the Cretaceous - it is composed of coarse sandstones, hard crystalline white limestones, clays, sands, phosphatic greensands, and darkcoloured, micaceous, glauconitic marls; its greatest thickness is about 280 ft.

Architectural variety and solidity are favoured in the buildings of the city by a wealth of beautiful building stones of varied colours (limestones, sandstones, lavas, granites and marbles), in addition to which bricks and Roman tiles are employed.

The Mesozoic begins with a Triassic land period in the mainland of Australia; while the islands of the Australasian festoon contain the Triassic marine limestones, which fringe the whole of the Pacific. The Triassic beds are best known in New South Wales, where round Sydney they include a series of sandstones and shales.

These movements in the south-east formed the Great Valley of Victoria, which traverses nearly the whole of the state between the Victorian highlands to the north, and the Jurassic sandstones of the Otway Ranges and the hills of south Gippsland.

There is a foundation of schists and crystalline rocks upon which rests a series of sandstones.

The Cambrian is represented by blue clays, ungulite sandstones and bituminous slates in Esthonia and St Petersburg.

In the extreme north-east are found the oldest rocks in the state - lower Devonian (the New Scotland beds of New York) and, not so old, an extension of the Lower Carboniferous which underlies the Warrior coalfields of Alabama, and which consists of cherts, limestones, sandstones and shales, with a depth of 800 to 900 ft.

The Grand Gulf group, of formations of different ages, consisting of sands, sandstones and clays, and showing a few fossil plants, but no marine fossils, extends southward from the last to within a few miles of the coast, and is 750-800 ft.

The shapes of these ferruginous sandstones are very fantastic - tubes, hollow spheres, plates, &c., being common.

The state contains deposits of iron, gypsum, marl, phosphate, lignite, ochre, glass-sand, tripoli, fuller's earth, limestones and sandstones; and there are small gas flows in the Yazoo Delta.

The intervening depression, which seems to be bounded on the west by a fault, is filled to a large extent by sandstones and marls of Eocene age.

Next in upward sequence is a thick mass of sandstones, grits and shales - the Millstone Grit series.

Most of the southern part of the county is occupied by Keuper marls and sandstones, the latter yield good building stone; and at Chellaston the gypsum beds in the former are excavated on a large scale.

Schists in the common acceptance of that term are really highly crystalline rocks; fissile slates, shales or sandstones, in which the original sedimentary structures are little modified by recrystallization, are not included in this group by English petrologists, though the French schistes and the German Schiefer are used to designate also rocks of these types.

Many of them have been originally micaceous or felspathic sandstones.

Towards the Caspian, especially between Petrovsk and the river Sulak, the Cretaceous system is well represented, and upon its rocks rest marls, shales, and sandstones of the Eocene period.

In the neighbourhood of Nottingham, and other places in the Midlands, barytes forms a cementing material in the Triassic sandstones; amber-coloured crystals of the same mineral are found in the fuller's earth at Nutfield in Surrey; and the septarian nodules in London Clay contain crystals of barytes as well as of calcite.

These are overlaid by conglomerates, tuffs, sandstones and arkoses, which perhaps do not all belong to the same period.

In the north the plateau is overlain by red and purple unfossiliferous sandstones, capped near its edge by a cherty limestone also unfossiliferous but possibly of Lower Cretaceous age.

Old Red Sandstone, red grits, sandstones and marls and conglomerate occur in a narrow belt on the east side of Mainland from Sumburgh Head to Rova Head, north of Lerwick; they also form the island of Bressay.

Besides huge masses of old schists and sandstones, the range contains extensive limestone, marble, diorite, basalt and porphyry formations, while granite prevails on its southern slopes.

These do not occur on the west coast, but on the east coast the German expedition discovered marls and sandstones on Kuhn Island, resembling those of the Russian Jurassic, characterized by the presence of the genus Aucella, Olcostephanus Payeri, 0.

Beds of this age, consisting of sandstones and coal, are found on the northern coast of Disco Island and the southern side of the Noursoak Peninsula, the beds in the former locality, " the Kome strata " of Nordenskiold, being the oldest.

Galena occurs in veins in the Cambrian clay-slate, accompanied by copper and iron pyrites, zinc-blende, quartz, calcspar, iron-spar, &c.; also in beds or nests within sandstones and rudimentary limestones, and in a great many other geological formations.

In the interior of Brazil, the Palaeozoic beds are directly overlaid by a series of red sandstones, &c., which appear to be of continental origin and of which the age is uncertain.

Fine white freestone abounds in the immediate vicinity (as at Craigleith, from the vast quarry of which, now passing into disuse, the stone for much of the New Town was obtained) and furnishes excellent building material; while the hard trap rock, with which the stratified sandstones of the Coal formation have been extensively broken up and overlaid, supplies good materials for paving and road-making.

The beds are usually thin false-bedded sandstones with an almost complete absence of shales.

The Ecca series graduates upwards into the highly coloured sandstones and shales of the Beaufort series.

This consists of sandstones and shales with thin seams of coal.

The Red beds and Cave sandstones occur along the eastern flanks of the Drakensberg.

Sandstones, quartzites, conglomerates and breccia make up the formation.

One is a red granite intruded subsequently to the Waterberg sandstones; another is a grey variety considered to be older than the Black Reef series and possibly older than the Witwatersrand series.

The Ecca series, as in the Cape, consists of sandstones and shales.

The overlying sandstones afford good building stones, and frequently, as at Vereeniging, yield many fossil plants.

The Lower Cretaceous consists chiefly of sandstones and shales and the Middle Cretaceous of very fossiliferous limestone.

The oldest rocks of Barbados, known as the Scotland series, are of shallow water origin, consisting of coarse grits, brown sandstones and sandy clays, in places saturated with petroleum and traversed by veins of manjak.

Hauran southward forms the main watershed of the peninsula is covered in places by deep beds of lava, which from their hardness have preserved the underlying sandstones from degradation, and now stand up consider ably above the general level.

The greater part of Tunisia is composed of sandstones, marls and loosely stratified deposits belonging to the Pliocene and Quaternary periods.

The Middle Eocene is characterized by the presence of Ostrea bogharensis and the Upper Eocene by highly fossiliferous sandstones and marls.

Geology.'--The Eastern Cordillera., which, however, is but little known, appears to consist, as in Bolivia, chiefly of Palaeozoic rocks; the western ranges of the Andes are formed of Mesozoic beds, together with recent volcanic lavas and ashes; and the lower hills near the coast are composed of granite, syenite and other crystalline rocks, sometimes accompanied by limestones and sandstones, which are probably of Lower Cretaceous age, and often covered by marine Tertiary deposits.

Above Lima the western chain of the Andes is composed of porphyritic tuffs and massive limestones, while the longitudinal valley of the Oroya is hollowed in carbonaceous sandstones.

Farther north, in the department of Ancachs, the Mesozoic belt is composed chiefly of sandstones and shales, and the limestones which form so prominent a feature above Lirna seem to have disappeared.

Slates and fine-grained sandstones appear here freely through the glacial drift.

It is formed almost entirely of a succession of sandstones and shales of Cretaceous and Tertiary age - the so-called Carpathian Sandstone - and these are thrown into a series of isoclinal folds dipping constantly to the south.

The geological formations thus exposed show that the plateaus are composed of a base of eruptive material, overlaid by enormous deposits of reddish sandstones, conglomerates and quartzites, exposed in parts to a depth of 2000 feet.

Hydrocarbons, such as petroleum, bitumen, paraffin, &c., are also found occasionally in coal, but more generally in the associated sandstones and limestones of the Carboniferous formation.

Such changes seem, however, to have been very rapidly accomplished, as pebbles of completely formed coal are commonly found in the sandstones and coarser sedimentary strata alternating with the coal seams in many coalfields.

It has been variously attributed to metamorphism, consequent upon igneous intrusion, earth movements and other kinds of geothermic action, greater or less loss of volatile constituents during the period of coaly transformation, conditioned by differences of permeability in the enclosing rocks, which is greater for sandstones than for argillaceous strata, and other causes; but none of these appears to be applicable over more than limited areas.

These are also called the Upper Limestone Shale, a similar group being found in places below the limestone, and called the Lower Limestone Shale, or, in the north of England, the Tuedian group. Going northward the beds of limestone diminish in thickness, with a proportional increase in the intercalated sandstones and shales, until in Scotland they are entirely subordinate to a mass of coal-bearing strata, which forms the most productive members of the Scotch coalfields.

The next member of the series is a mass of coarse sandstones, with some slates and a few thin coals, known as the Millstone Grit, which is about equally developed in England and in Scotland.

The Coal Measures, forming the third great member of the Carboniferous series, consist of alternations of shales and sandstones, with beds of coal and nodular ironstones, which together make up a thickness of many thousands of feet - from 12,000 to 14,000 ft.

The actual coal measure strata, consisting mainly of shales and clays, are generally impervious to water, but when strata of a permeable character are sunk through, such as the magnesian limestone of the north of England, the Permian sandstones of the central counties, or the chalk and greensand in the north of France and Westphalia, special methods are required in order to pass the water-bearing beds, and to protect the shaft and workings from the influx of water subsequently.

The value of the product of limestones and dolomites in 1900 was $124,728; in 1902, $228,662; of sandstones and quartzites in 1900, $37,038; in 1902, $165,565; while the value of all stone produced in 1907 was $497,962, and in 1908, $ 6 59,574.

They are underlain by Jurassic rocks, from beneath which sandstones and shales yielding Glossopteris browniana var.

In the vicinity of Lakes Nyasa and Tanganyika, sandstones and shales of Lower Karroo age and yielding seams of coal are considered to owe their position and preservation to being let down by rift faults into hollows of the crystalline rocks.

In Karagwe certain quartzites, slates and schistose sandstones resemble the ancient gold-bearing rocks of South Africa.

Coal has been observed in the Purari sandstones.

Geologically the region is made up of Carboniferous limestones, clay slates and sandstones, containing anthracite and coal; of Cretaceous marls, chalk, sandstone and greensands - chalk cliffs, in fact, accompany the Don for 200 m.; and of Miocene limestones and clays.

Here, partly because of elevation, and partly because of the resistant nature of the Catskill sandstones, dissection has so sculptured the plateau as to carve it into a mountainous mass which is generally known as the Catskill mountains.

Medina sandstones occur throughout a belt averaging about 10 m.

The value of all sandstones quarried in 1908 was $1,774,843, an amount exceeded by no other state.

The Maitai beds include a thick mass of slates and sandstones, which form the bulk of the Southern Alps, whence branches extend southeastward to the coast.

It consists mainly of sandstones, but these are often thin-bedded and pass into shales.

The prevailing rocks are sandstones, mudstones and shales.

The total value of all mineral products in 1902 was $6,769,104, of which $6,464,258 were represented by gold and silver, $110,789 by sandstones and quartzites and $86,605 by limestones and dolomites; in 1908 the total value was $8,528,234, which was an i increase of more than $3,500,000 over the value in 1907.

They are rarely metamorphosed to the point of recrystallization, though locally shales are altered to roofing slates, sandstones are indurated, limestones slightly marblized, and coals, originally bituminous, are changed to anthracite in northern Pennsylvania, and to graphite in Rhode Island.

Former tributaries have given place to others developed with reference to the distribution of more or less easily eroded strata, the present longitudinal valleys being determined by the out-crop of soft shales or soluble limestones, and the parallel ridges upheld by hard sandstones or schists.

Among the rocks of economic importance may be mentioned granite of numerous kinds, syenite, serpentine, porphyry, marble, sandstones and marls.

At Cushendun, however, a coarse conglomerate is believed to be Devonian, while Lower Carboniferous Sandstones, with several coal-seams, form a small productive basin at Ballycastle.

The Maryland building stone, of which there is an abundance of good quality, consists chiefly of granites, limestones, slate, marble and sandstones, the greater part of which is quarried in the east section of the Piedmont Plateau especially in Cecil county, though some limestones, including those from which hydraulic cement is manufactured, and some sandstones are obtained from the western part of the Piedmont Plateau and the east section of the Appalachian region; the value of stone quarried in the state in 1907 was $1,439,355, of which $1,183,753 was the value of granite, $142,825 that of limestone, $98,918 that of marble, and $13,859 that of sandstone.

At Jebel-kahar and west of Traras, Pomel attributes certain conglomerates, red sandstones and purple and green shales to the Permian.

The highest beds, consisting of quartzites, shales, marls and sandstones with the remains of fucoids, are found in the Jurjura and Shellata.

The Oligocene period consists of a marine phase confined to the littoral zone of Kabylia, and of a continental phase occupying vast areas composed of lacustrine, alluvial, gypsiferous marls, sandstones and conglomerates.

Jefferson, Jessamine, Warren, Grayson and Caldwell counties have valuable quarries of an excellent light-coloured Oolitic limestone, resembling the Bedford limestone of Indiana, and best known under the name of the finest variety, the " Bowling Green stone " of Warren county; and sandstones good for structural purposes are found in both coal regions, and especially in Rowan county.

The former consists of sandstones and clays, and the fossils found in.

The Jurassic beds are marls, sandstones and limestones, which contain marine fossils.

The exposed strata are in large part resistant sandstones.

A significant exception to the rule of mature valleys occurs, however, in the case of the Missouri, the largest river, which is broken by several falls on hard sandstones about 50 m.

A wonderful series of these forms occurs in southern Utah, where in passing northward from the Carboniferous platform one ascends in succession the Vermilion Cliffs (Triassic sandstones), the ViThite Cliffs (Jurassic sandstones, of remarkably cross-bedded structure, interpreted the dunes of an ancient desert), and finally the Pink Cliffs (Eocene strata of fluviatile and lacustrine origin) of the high, forested plateaus.

Associated with these irregular escarpments are occasional rectilinear ridges, the work of extensive erosion on monoclinal structures, of whick Echo Cliffs, east of the Painted Desert (so called from its manycoloured sandstones and clays), is a good example.

In the eastern half of the country the system consists of shales and sandstones chiefly, btit there is some limestone, and coal enough to be of great importance economically, though it makes but a small part of the system quantitatively.

Most of the plains are underlain by Cretaceous and early Tertiary shales and sandstones lying nearly unaltered and undisturbed where they were deposited, although now raised far above sea-level, particularly along the border of the Rocky Mountains where they were thrust up into foot-hills when the range itself was raised.

The Old Man presents a characteristic section, for it exhibits a thick pile of massive, current-bedded red sandstones, resting, near the foot of the pinnacle, upon a thin bed of amygdaloidal porphyrite, which in its turn lies unconformably upon steeply inclined flagstones.

The Lower Old Red Sandstone is represented by well-bedded flagstones over most of the islands; in the south of Pomona these are faulted against an overlying series of massive red sandstones, but a gradual passage from the flagstones to the sandstones may be followed from Westray S.E.

This is an undulating plain which has been produced by the wearing away of weak sandstones, &c. On the north and west borders of this plain are two parts of a chain of semi-detached and usually rounded hills, known as the South Mountains.

Both of these ranges of hills are composed of hard crystalline rocks, and between them lies the lowland eroded on the weaker sandstones and sediments.

There is some of the same formation as well as that derived from red shales on the sandstone hills in the south-east province and in many of the middle and western valleys, but often a belt of inferior slate soil adjoins a limestone belt, and many of the ridges are covered with a still more sterile soil derived from white and grey sandstones.

Several of the western counties contain Carboniferous or sub-Carboniferous sandstones that are used locally for building and for various other purposes.

They appear in some cases to be altered limestones and in others altered glauconitic sandstones.

The Molasse, in the neighbourhood of the mountains, consists chiefly of conglomerates and sandstones, and the Flysch consists of sandstones and shales; but the Molasse is of Miocene and Oligocene age, while the Flysch is mainly Eocene.

The Flysch is an extraordinarily thick and uniform mass of sandstones and shales with scarcely any fossils excepting fucoids.

North of the Danube, in Germany as in England, red sandstones, shales and conglomerates predominate, together with beds of gypsum and salt.

They consist largely of limestone; but marls and sandstones are by no means rare, and there are considerable gaps in the succession indicating that the region was not continuously beneath the sea.

The stratified rocks of this system include marine limestones, shales and sandstones; estuarine, lagoonal and fresh-water shales, sandstones and marls with beds of coal, oil-bearing rocks, gypsum and salt.

The so-called " unproductive " or barren strata, that is, those without workable coals, are not always limestones; quite as often they are shales, red sandstones and red marls.

The sandstones are used for building, and for millstones and grindstones.

No Permian beds are known, and for many years Mesozoic deposits were supposed to be entirely absent, but Triassic clays and sandstones with Daonella have been found in the upper part of the basin of the Kwalu (East Sumatra).

They consist of breccias, conglomerates, sandstones, marls, and limestones, with seams of coal and lignite.

The Devonian sandstones contain malachite ores near Kielce, and copper has been worked there since the 15th century, though the mines are now neglected.

The diamond is here found in ancient sandstones and conglomerates, and in the river gravels and sands derived from them.

From the edge of the coast belt to near the confluence of the Benue and Niger they are overlain by unfossiliferous sandstones, lying undisturbed and possibly of the age of the sandstones of the Congo basin.

Such casts are not infrequent in the Keuper marls and sandstones, and in the Purbeck beds of England.

While rocks and boulders are the favoured situation for the growth of marine algae, those which readily disintegrate, like the coarser sandstones, are naturally less favoured than the hard and resistant.

Next follow the Bala Beds, which, with the succeeding Lower and Upper Llandovery shales, sandstones and conglomerates, form the sparsely populated sheepwalks and valleys which occupy most of the north-western part of the county.

These rocks are much folded and the shales are locally cleaved into slates, while the sandstones and conglomerates form scarps and ridges.

To the south-east of this region a narrow outcrop of Upper Llandovery, Wenlock and Ludlow sandstones and mudstones follows, uncomformably overlying the Llandeilo and Bala rocks, and dipping conformably under the Old Red Sandstone; they extend from Newbridge-on-Wye and Builth through Llangammarch (where there are mineral springs) towards Llandovery, while a tongue of Ludlow rocks brought up by faulting extends from Erwood on the Wye for 8 m.

Crystalline rocks crop out at several capes; Cretaceous limestones, containing an abundant and specific fauna of gigantic ammonites, occur at Dui on the west coast, and Tertiary conglomerates, sandstones, marls and clays, folded by subsequent upheavals, in many parts of the island.

On the west the most notable cliffs south of those of Cape Wrath and the Cambrian sandstones of Sutherland are to be found among the basaltic islands, particularly in Skye, where a magnificent range of precipices rising to moo ft.

The Upper Silurian shales and sandstones appear only along the northern and southern margins.

To this division are assigned the yellow sandstones of Elgin, which have yielded crocodilian and other reptilian remains, the discovery of which led to the rocks being separated from the Upper Old Red Sandstone, to which they had previously been thought to belong.

There occur also below the Lias on some parts of the west coast unfossiliferous red sandstones, conglomerates and breccias, presenting lithological resemblance to the Rhaetic group of England.

Red sandstones and conglomerates, probably of the same age, attain a thickness of several hundred feet at Gruinard Bay on the west coast of the county of Ross and Cromarty.

The Middle Oolite consists mostly of sandstones with bands of shale and limestones, and includes fossils which indicate the English horizons from the Kellaways Rock up to the Coral Rag.

The lower part of the Kimmeridge Clay is probably represented by sandstones and conglomerates, forming the highest beds of the series in Sutherland.

The Lower, Middle and Upper Lias consist chiefly of shales and shelly limestones, with some sandstones, well seen along the shores of Broadford Bay in Skye and in some of the adjacent islands.

The Lower Oolites are made up of sandstones and shales with some limestones, and are overlaid by several hundred feet of an estuarine series of deposits consisting chiefly of thick white sandstones, below and above which lie shales and shelly limestones.

Some greenish sandstones containing recognizable and characteristic fossils are the equivalents of the Upper Greensand of the south of England.

They are covered by white sandstones and these by white chalk and manly beds, which represent the Upper Chalk of England.

These ancient rocks, which form the foundation of the country, are overlaid unconformably by a series of conglomerates and sandstones, generally unfossiliferous and often red or purple in colour, very similar in character to the Nubian sandstone of Upper Egypt.

The central plateau consists of ancient crystalline rocks with granites overlain by unfossiliferous sandstones and conglomerates considered to be of Palaeozoic age.

The sandstones with gypsum, copper and sulphur of Dombe are doubtfully considered to be of Triassic age.

These are overlaid by a limestone, upon which rests conformably a series of sandstones with coal seams. The age of these beds is unknown.

Carboniferous beds, consisting chiefly of slates, sandstones and conglomerates, are found in the south-eastern provinces.

In structure they are monoclinical, their rocks - sandstones and shales - being laid southward and blending on that side with the Arkansas valley region.

Consisting of red sandstones, mudstones and conglomerates, they are inclined at high angles usually away from the granite massif and the encircling metamorphic rocks.

The small development of Upper Carboniferous strata, visible on the shore south of Corrie and in Ben Lister Glen, consists of sandstones, red and mottled clays and purple shales, which yield plantremains of Upper Carboniferous facies.

The Triassic rocks are arranged in two groups, a lower, composed of conglomerates and sandstones, and an upper one consisting of red and mottled shales and marls with thin sandstones and nodular limestones.

Sandstones and quartzites were also quarried in 1902 in Albany, Crook and Uinta counties.

The geology of Borneo is very imperfectly known The mountain range which lies between Sarawak and the Dutch possessions, and may be looked upon as the backbone of the island, consists chiefly of crystalline schists, together with slates, sandstones and limestones.

The Tertiary system includes conglomerates, sandstones, limestones and marls, which appear to be of Eocene, Oligocene and Miocene age.

Certain markings on slates and sandstones, such as the "fucoids" of Scandinavia and Scotland, the Phycoides of the Fichtelgebirge, Eophyton and other seaweed-like impressions, may indeed be the casts of fucoid plants; but it is by no means sure that many of them are not mere inorganic imitative markings or the tracks or casts of worms. Oldhamia, a delicate branching body, abundant in the Cambrian of the south-east of Ireland, is probably a calcareous alga, but its precise nature has not been satisfactorily determined.

At the base is the so-called "blue clay" (really greenish) with ferruginous sandstones and with a fucoidal sandstone at its summit.

Evidences of shallow water conditions arc abundant; very frequently on the bedding surfaces of sandstones and other rocks we find cracks made by the sun's heat and pittings caused by the showers that fell from the Cambrian sky, and these records of the weather of this remote period are preserved as sharply and clearly as those made only to-day on our tidal reaches.

Occasional hard rock ridges rise to a moderate elevation above the general level, while areas of unusually weak Triassic sandstones have been worn down to form lowlands.

The shores of the Bosporus are composed in the northern portion of different volcanic rocks, such as dolerite, granite and trachyte; but along the remaining course of the channel the prevailing formations are Devonian, consisting of sandstones, marls, quartzose conglomerates, and calcareous deposits of various kinds.

On both sides the range is flanked by sandstones and shales (the Kythraean series), supposed to be of Upper Eocene age; and similar rocks occur around the southern mountain mass.

It occurs in a series of amygdaloidal dolerites or diabases, and in the associated sandstones and conglomerates.

The older rocks are overlaid unconformably by Cretaceous beds, consisting chiefly of sandstones with seams of coal, the whole series thinning rapidly towards the north and thus indicating the neighbourhood of the old shore-line.

It was entirely covered with the bottom moraine of the great ice-sheet of the Glacial Epoch, resting upon Silurian sandstones and limestones.

The Silurian has in Sweden almost the same character as the Wenlock and Ludlow formation of England and consists partly of graptolite shales, partly of limestones and sandstones.

It consists partly of sandstones with impressions of plants (cycads, ferns, &c.), and partly of clay-beds with coal.

The deposits are marls, sandstones and limestones, and were evidently formed near the shore-line.

Westwards, looking towards Afghanistan, line upon line of broken jagged ridges and ranges, folds in the Cretaceous series overlaid by coarse sandstones and shales, follow each other in order, preserving their approximate parallelism until they touch the borders of Baluchistan.

Recent; d =Upper Siwalik conglomerates c =J,fiddle Siwalik sandstones; b=Lower (Nahan) siwalik.s; a .

The deposits in these basins consist largely of coarse sandstones and conglomerates, amongst which lie seams of coal.

The eastern ranges of the Bolivian Andes are formed of Palaeozoic rocks with granitic and other intrusions; the Western Cordillera consists chiefly of Jurassic and Cretaceous beds, together with the lavas and ashes of the great volcanoes; while the intervening plateau is covered by freshwater and terrestrial deposits through which rise ridges of Palaeozoic rock and of a series of red sandstones and gypsiferous marls of somewhat uncertain age (probably, in part at least, Cretaceous).

The Palaeozoic beds are directly overlaid by a series of red sandstones and gypsiferous marls, similar to the formacion petrolifera of Argentina and Brazil.

Along the Colorado is the Painted Desert, remarkable for the bright colours - red, brown, blue, purple, yellow and white - of its sandstones, shales and clays.

The southern parts of the central range are composed of granites, syenites, porphyries and crystalline slates, while in the north of Ichinskaya volcano, which is the highest summit of the peninsula (16,920 ft.), the mountains consist chiefly of Tertiary sandstones and old volcanic rocks.

Coalbearing clays containing fresh-water molluscs and dicotyledonous plants, as also conglomerates, alternate with the sandstones in these Tertiary deposits.

The rocks consist of sandstones, quartzites, slates and shales, associated with lenticular masses of limestone.

The typical Silurian rocks are richly fossiliferous, the shales containing trilobites, the sandstones many brachiopods, and the limestones a rich coral and bryozoan fauna.

In the extreme south-east of New South Wales, at the head of the Genoa river, are sandstones with Archaeopteris howitti, which are an extension of the Lower Devonian beds of Victoria; while farther to the east, at Eden and Twofold Bay, are Upper Devonian sandstones.

The Lower Carboniferous beds are represented by conglomerates and sandstones with some shales and limestones.

The sandstones are characterized by Lepidodendron (Bergeria) australe.

Farther south they disappear beneath the Mesozoic sandstones, from which they again rise along the coast around Lake Illawarra and near the mouth of the Shoalhaven river.

The Mesozoic rocks of New South Wales begin with the Narrabeen Shales; they are covered by the Hawkesbury Sandstones, which are well exposed around Sydney; and they in turn are covered by the Wianamatta Shales.

The " Waterstones," or Lower Keuper Sandstones, - forming gentle elevations above the softer marls, and usually charged with an abundant supply of water, which can be reached by wells, - form the site of many towns, such as Birmingham, Warwick and Lichfield, and of very numerous villages.

Each group is made up of an alternation of soft marls or clays and hard limestones or sandstones.

From the middle of this plain the core of Lower Cretaceous sandstones known as the Hastings Beds emerges steeply, and reaches in the centre an elevation of 796 ft.

But, on the other hand, the broad clay plains of all formations, the Cretaceous sandstones, and the Triassic plain, are peopled more densely than any other district without mineral wealth or sea trade.

The Triassic rocks, red sandstones, marls and conglomerates cover a broad area in the Midlands in Worcestershire, Warwickshire and Leicestershire, whence they may be followed south-westward through Somerset to the coast at Sidmouth, and northward, round either flank of the Pennine Hills, through Nottinghamshire and Yorkshire to Middlesbrough on the one hand, and upon the other through Staffordshire, Cheshire and Lancashire to Carlisle.

The western and eastern shores consist of boulder clay, as well as a narrow strip on the southern shore, south of which runs a ridge of crags of Silurian sandstones.

The portion of the great basin of the Congo included in the colony is mainly occupied, so far as it has been explored, by sandstones.

These are separable into a lower group (Kundelungu) of red felspathic grits and into an upper group (Lubilasch) of white friable sandstones.

The basin in which these sandstones were laid down is limited on the east by ancient gneisses and schists overlain by the highly inclined red felspathic grits.

In the region of Adigrat the metamorphic rocks are invariably overlain by white and brown sandstones, unfossiliferous, and attaining a maximum thickness of moo feet.

They are interbedded with unfossiliferous sandstones and shales.

Quartz being a mineral very resistant to weathering agencies, it forms the bulk of sands and sandstones; and when the sand grains are cemented together by a later deposit of secondary quartz a rock known as quartzite results.

Limestones are by far the most important; red and gray granites, sandstones and marble (Ste Genevieve county) being of little more than local importance.

These are overlaid by sandstones, slates and limestones, alternating with porphyries and porphyrites, sometimes in the form of sheets, sometimes as breccias and conglomerates.

The low Cordilleras of the Chocos, on the west coast, are covered by soft Quaternary sandstones and marls containing shells of extant species, such as still inhabit the neighbouring ocean.

The Western Cordillera is the direct continuation of the Western Cordillera of Ecuador, and, like the latter, to judge from the scattered observations which are all that are available, consists chiefly of sandstones and porphyritic rocks of the Cretaceous series.

On the western side of this depression there are red sandstones with coal-seams, possibly Tertiary; the floor and the eastern side consist chiefly of ancient crystalline and schistose rocks.

The lowest member (Table Mountain Sandstone) consists of sandstones with subordinate bands of shale.

The Table Mountain Sandstone passes up conformably into a sequence of sandstones and shales (Bokkeveld Beds), well exposed in the Cold and Warm Bokkevelds.

The Bokkeveld beds are conformably succeeded by the sandstones, quartzites and shales of the Witteberg series.

The Jurassic beds are marine and contain numerous Ammonites, but the beds which are referred to the Neocomian include a series of sandstones and shales with remains of plants.

There are marbles in Osage and other counties, shell marble in Montgomery county, white limestone in Chase county, a valuable bandera flagstone and hydraulic cement rock near Fort Scott, &c. The limestones produced in 1908 were valued at $403,176 and the sandstones at $67,950.

In the northern Apennines the elevation of the sea floor appears to have begun at an earlier period, for the Upper Cretaceous of that part of the chain consists largely of sandstones and conglomerates.

The Alai is a well-defined ridge with steep slopes, and both it and the Terek-tau, which prolongs it towards the Kokshal-tau, are flanked next the Ferghana valley by what appear to be the old uplifted strata both of the old Palaeozoic series of metamorphic limestones and of the newer Tertiary series of softer conglomerates and sandstones.

They come out as mica-schists under the Carboniferous sandstones of northern Antrim, and disappear southward under the basaltic plateaux.

On either flank the Silurian shales, slates and sandstones, which are very rarely fossiliferous, rise with steep dips.

Its lower part represents the Lower Carboniferous Shales and Sandstones of the central and northern areas, while its upper part corresponds with a portion of the Carboniferous Limestone.

The Lower Carboniferous Sandstones are conspicuous in the region from Milltown near Inver Bay in southern Donegal to Ballycastle in county Antrim.

The beds above the limestone are shales and sandstones, sometimes reaching the true Coal-Measures, but rarely younger than the English Millstone Grit.

The Triassic sandstones and marls, with marine Rhaetic beds above, are preserved mainly round the basaltic plateaus of the north-east, and extend for some distance into county Down.

Dark " green-sands," very rich in glauconite, are followed by yellow sandstones with some flint.

The lowest members of these rest directly upon the central mass of crystalline rocks, and consist of sandstones, conglomerates and shales, which have been supposed by some to belong to the Trias, without, however, the discovery of any fossil necessary to confirm this supposition, except some silicified trunks of trees.

Some unfossiliferous conglomerates, sandstones and dolomites in South Africa and on the west coast are considered to belong to the Cambrian, Ordovician and Silurian formations, but merely from their occurrence beneath strata yielding Devonian fossils.

The Lower Carboniferous rocks of Spain consist partly of limestones, and partly of shales, sandstones and conglomerates like the culin of Devonshire.

The Upper Carboniferous is formed to a large extent of sandstones and shales, with seams of coal; but beds of massiye limestones are often intercalated, and some of these contain Fusaljna and other fossils like those of the Russian Ftisulina limestone.

The Permian is probably represented by some of the red sandstones, conglomerates and shales in the Pyrenees, in the Serrania de Cuenca, and in Andalusia.

It is composed of red and variegated sandstones, dolomites and marls, traversed in some places by ophitic rocks, and containing deposits of gypsum, aragonite and rocksalt, It thus resembles the Trias of England and Germany.

The lower members of the Cretaceous series include an important fresh-water formation (sandstones and clays), which extends from the Cantabrian coast through the provinces of Santander, Burgos, Soria and Logrono, and is supposed to represent the English Wealden series.

The marine Tertiary accumulations commence with those that are referable to the Eocene series, consisting of nummulitic limestones, marls and siliceous sandstones.

Red and grey sandstones, hornblende and argillaceous schist are found in the mountains, porphyry and basaltic rocks also occur; sulphur and fuller's earth are worked.

The Congo sandstones do not appear to extend as far north.

These mountains consist of detached remnants of a sheet of quartz conglomerates, interbedded with sandstones, containing crinoid stems and obscure brachiopods.

It is usually regarded as beginning with a fresh-water series containing the remains of fish and labyrinthodonts; but as it also contains Vertebraria it is probably Palaeozoic; and this series is covered by sandstones and shales which are probably of Triassic age.

Another plant found in the Vosges sandstones - Neuropteridium grandifolium - is also closely allied to species of the same i ` fern " recorded from the.

In the central parts of North America the lacustrine plant-bearing deposits are of enormous thickness, the Dakota series being followed by marine Cretaceous strata known as the Colorado and Montana groups, and these being succeeded conformably by a thousand feet or more of lacustrine shales, sandstones and coal-seams, belonging to the Laramie series.

As the impurities increase in amount the clay rocks pass gradually into argillaceous sands and sandstones, argillaceous limestones and dolomites, shaly coals and clay ironstones.

It consists of parallel ridges and valleys developed by erosion on folded sandstones, shales and limestones, the valley quality predominating because the weak limestones were of great thickness.

The Eocene includes a series of sandstones and marls with lignite, and these are overlaid by nummulite limestones.

Among such substances are fireclay and firebricks, certain sandstones, silica in the form of ganister, and Dinas stone and bricks, ferric oxide and alumina, carbon (as coke and graphite), magnesia, lime and chromium oxide - their relative importance being indicated by their order, the last two or three indeed being only of limited use.

The red and white sandstones looked blocky in places and were fragmented by joints.

The lowest unit, the Llandovery Series, comprises coarse sandstones and conglomerates and siltstones with abundant fossil brachiopods and trilobites.

The sandstones have more quartz and glauconite, and are only loosely cemented together by calcite.

Where there is plenty of quartz cement it produces hard sandstones and conglomerates.

In a well near the middle of the Eastern Depocentre, the unit comprises mostly silty claystone, with sandstones up to 5m thick.

In other areas mudstones have been found with microfossil plant spores and one of the later sandstones near Cheadle has fossil footprints of reptiles.

South of the Clougher Valley the carboniferous limestones have sandstone deposited on top with beds of shale contained in the sandstones.

Current levels are also relatively healthy in most western Permo-Triassic sandstones outcrops.

These comprise quartzites, sandstones and shales that are exposed at the southern end of the Malvern Hills.

Upon a plinth of Torridonian sandstones lies the continuous cliff-line of bright white Cambrian quartzites.

This situation is broadly replicated in the limestone aquifers but the Permo-Triassic sandstones display much less geographical coherence.

Such features could provide additional small sources of " fresh " flints, together with some input from the eroding Eocene sandstones.

The same applies to the Permo-Triassic sandstones of the South West; elsewhere levels are generally low albeit above corresponding levels in 1997.

Lower Paleozoic greywacke sandstones were deposited in a deep marine environment and may have volcanic ash beds and conglomerates within.

Here, although exposures are very poor, the Silurian rocks comprise shales, sandstones and limestones with a couple of beds of lava.

The hard ' grit ' sandstones and intervening shales of the Millstone Grit outcrop west of Bradford and to the north of Leeds.

The sedimentary schists or paraschists have three great subdivisions, the mica-schists and chlorite-schists (which correspond in a general way to shales or clay rocks) the calc-schists (impure limestones) and the quartz-schists (metamorphosed sandstones).

Between the "Cotton Belt" and the Tennessee Valley is the mineral region, the "Old Land" area - "a region of resistant rocks" - whose soils, also derived from weathering in situ, are of varied fertility, the best coming from the granites, sandstones and limestones, the poorest from the gneisses, schists and slates.

In the Ardennes the system is represented by grits and sandstones, shales, slates and quartz schists, and includes also whet slates and some igneous rocks.

The Karroo system (sandstones and marls) covers immense areas (see Africa, § Geology).

Tertiary limestones, sandstones and shales overlie the Deccan Trap in Cutch, but the greatest development of deposits of this age is to be met with on the western side of the Indus (see Sind).

The sandstones commonly contain grains of felspar - a complex silicate of alumina and an alkaline base.

Contemporaneous volcanic rocks are associated with the Ordovician beds and with the Rhaetic sandstones in several places.

The Devonian dolomites, limestones and red sandstones cover immense tracts and appear on the surface over a much wider area.