Beginning in the south-east corner of the Gold Coast colony this range, composed of quartzites and schists, extends beyond the borders of Togoland into upper Dahomey.
The dark bituminous layers of clay slate, which occur intercalated among the quartzites, have led, here as elsewhere, to the hope of coming upon a seam of coal, but it is contrary to experience that coal of any value should be found in rocks of that age.
Many of the block mountains of the Great Basin are of complicated internal structure, showing rocks of all ages - slate, limestone, quartzites, granite, multi-coloured volcanic rocks, and large areas of lava overflow.
The metamorphic rocks of the rest of Mainland are principally coarse gneisses, micaceous and chloritic schists, quartzites, &c.; in these rocks at Tingwall and Wiesdale considerable beds of limestone occur, which may be followed across the island in a northerly direction to Yell Sound, and to Dales Voe in Delting.
Quartzites, Conglomerates and Shales of Nkandhla, Umfolosi river.
A group of highly inclined quartzites, altered conglomerates and jasperoid rocks which crop out on the Umhlatuzi river, between Melmoth and Nkandhla and on the White Umfolosi river above Ulundi Ph ins, is considered by Anderson to represent some portion of the Lover Witwatersrand series.
- a lower group (Hospital Hill series) of quartzites, shales and conglomerates.
Barberton and Swaziland Crystalline schists, quartzites, conglomSeries.
They show a great variety of type made up of slates, quartzites, occasional conglomerates, schists with large masses of intrusive granites and gneiss.
The lower group (Hospital Hill slates) consists of quartzites and shales, resting on the eroded surface of the older granites and schists, and estimated to be from 10,000 to 12,000 ft.
The upper group consists of conglomerates, grits and quartzites with a few bands of shales.
The conglomerate bands and quartzites contain large quantities of iron pyrites deposited subsequent to their formation, that in the conglomerates containing the gold.
The Black Reef Series is composed of quartzites, sandstone, slates and conglomerate.
The Pretoria Series, formerly known as the Gatsrand series, consists of repeated alternations of flagstones and quartzites, shales and sheets of diabase.
Sandstones, quartzites, conglomerates and breccia make up the formation.
They are often overlain by schists and quartzites, or broken through by volcanic masses.
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.
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.
In Karagwe certain quartzites, slates and schistose sandstones resemble the ancient gold-bearing rocks of South Africa.
This boss is bounded, except on the south, by the Witwatersrand series, the lower portion of which consists of quartzites and slates and the upper portion of quartzites and conglomerates.
The Black Reef series of quartzites and conglomerates and dolomite form a narrow outcrop resting unconformably upon the last-mentioned system.
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 consist of gneiss, mica-schist, quartzites, crystalline limestones and conglomerates.
The highest beds, consisting of quartzites, shales, marls and sandstones with the remains of fucoids, are found in the Jurjura and Shellata.
In Wisconsin the inner lowland presents an interesting feature in a knob of resistant quartzites, known as Baraboo Ridge, rising from the buried oldland floor through the partly denuded cover of lower Palaeozoic strata.
A series of quartzites and slates referred to the Cambrian, and holding numerous and important veins of auriferous quartz, characterize its Atlantic or southeastern side, while valuable coal-fields occur in Cape Breton and on parts of its shores on the Gulf of St Lawrence.
The wild and barren west of this county, including the great hills on Achill Island, is formed of "Dalradian" rocks, schists and quartzites, highly folded and metamorphosed, with intrusions of granite near Belmullet.
Traces of annelids have been detected in some of the quartzites, and some of the less changed parts of the limestones may be searched for fossils.
The quartzites rise in conical hills, such as those of Jura and Islay.
The quartzites themselves have also been subjected to extraordinary horizontal displacement, amounting in places to not less than Io m.
Rocks of Cambrian age have not been identified elsewhere in Scotland, though it may ultimately be shown that the quartzites and limestones of the Central Highlands are equivalents of those of the north-west coast.
Sandstones and quartzites were also quarried in 1902 in Albany, Crook and Uinta counties.
Thus, we find them more frequently, folded, tilted and cleaved; the muds have become shales, slates, phyllites or schists, the grey and red sands and conglomerates have become quartzites and greywackes, while the limestones are very generally dolomitized.
The Cambrian system is covered by his stages "B" and "C"; the former a barren series of conglomerates and quartzites, the latter a series of grey and green fissile shales 1200 ft.
In the Rennes basin limestones - often dolomitic - are associated with quartzites and conglomerates; silicious limestones also occur in the Sarthe region.
In Spain slates and quartzites, the slates of Rivadeo, more than 9000 ft.
Thick, are followed by the middle Cambrian beds of La Vega, thick quartzites with limestone, slates and iron ores.
In Russian Poland is a series of conglomerates, quartzites and shales; some of the beds yield a Paradoxides fauna.
In the western and northern alpine part of Sweden, near the boundaries of Norway, the Silurian strata are covered by crystalline rocks, mica schists, quartzites, &c., of an enormous thickness, which have been brought into their present positions upon a thrust-plane.
The primary rocks which appear at Mitushev Kamen are overlaid with thick beds of quartzites and clayslates containing sulphide of iron, with subordinate layers of talc or mica slate, and thinner beds of fossiliferous limestone, Silurian or Devonian.
The rocks consist of sandstones, quartzites, slates and shales, associated with lenticular masses of limestone.
Granites and granodiorites were intruded at this period into the older rocks, and altered the adjacent Devonian beds into slates and quartzites, and formed gold-quartz veins, which have been worked in the Devonian rocks at Yalwal.
Cambrian strata appear in Shropshire in the form of sandstones and quartzites; in the Malvern Hills they are black shales, while in the >>
The oldest, or Keis, series consists of quartzites, quartz-schists, phyllites and conglomerates.
These are overlain, perhaps unconformably, by a great thickness of lavas and volcanic breccias (Pniel volcanic series, Beer Vley and Zeekoe Baard amygdaloids), and these in turn by the quartzites, grits and shales of the Black Reef series.
Among the Griquatown series of quartzites, limestones and shales are numerous bands of jasper and large quantities of crocidolite (a fibrous amphibole); while at Blink Klip a curious breccia, over 200 ft.
The Ongeluk volcanic series, consisting of lavas and breccias, conformably overlies the Griquatown series; while the grits, quartzites and conglomerates of the Matsap series rest on them with a great discordance.
The Bokkeveld beds are conformably succeeded by the sandstones, quartzites and shales of the Witteberg series.
Slates, schists, quartzites and limestones form the greater part of the hills, but the Brocken and Victorshohe are masses of intrusive granite, and diabases and diabase tuffs are interstratified with the sedimentary deposits.