Archean rocks - gneiss, schist and granite - cover large areas through which the Nile cuts its way in alternate narrow gorges and open reaches.
A quartz schist, suitable for making whetstones and oilstones, was discovered in 1823 by Isaac Pike at Pike Station, Grafton county, and the Pike Manufacturing Company now owns and operates quarries outside this state also; in 1907 New Hampshire was the principal producer of scythe-stones in the United States, and the total value of whetstones made in 1907 (including the value of precious stones') was $59,870.
The oldest rocks of Elba consist of schist and serpentine which in the eastern part of the island are overlaid by beds containing Silurian and Devonian fossils.
Graphite occurs mainly in the older crystalline rocks - gneiss, granulite, schist and crystalline limestone - and also sometimes in granite: it is found as isolated scales embedded in these rocks, or as large irregular masses or filling veins.
It is not volcanic, but consists of argillaceous schist and quartzite.
Archean Great Schist Series (Mona, Kitchi, Keewatin, Quinnissec; Lower Huronian of some L authors).
The rocks of the granitoid series appear as great masses in the schist series, and in some places form great protruding bosses.
Nearly all known sorts of schist are represented in the schistose nart of the system.
The commoner sorts of rock in the several Huronian systems are quartzite and slate (ranging from shale to schist); bi~t limestone is not wanting, and igneous rocks, both intrusive and extrtisive, some metamorphic and some not, abound.
Conway schist Amherst schist - ~.-5ooo (~)
Goshen schist 2000, , (?)
Hawley schist 2000 ft.
Savoy schist 5000, , ?)
Rowe schist 4000, , (?)
Hoosic schist 1500, , (?)
Gneiss & Mica Schist A-G.
The oldest rocks are gneiss, schist and quartzite, the schist often containing gold.
The Cordillera, which bounds them on the west, is formed of folded beds, while the Sierras which rise in their midst, consist mainly of gneiss, granite and schist.
The next geological formation which is represented is the Eocene, consisting of nummulitic limestone, sandstone and schist.
- The Somaliland plateau is chiefly composed of gneiss and schist.
Beneath there appears to be an unbroken surface of mica schist.
The water which has found its way through the granitic sand flows over the surface of the mica schist and settles in the hollows, and by sinking wells to the solid rock a supply of water can generally be obtained.
They consist chiefly of gneiss and schist, with granite and other eruptive rocks.
Archean gneiss, Cambrian sandstone, Silurian quartzite, limestone and schist, Jurassic sandstone and limestone, Cretaceous sandstone, and Tertiary basalts, gabbros, and granitic rocks all enter into the composition of the islands.
The Eastern Cordillera is composed of gneiss, mica and chlorite schist and other crystalline rocks of ancient date; the Western Cordillera, on the other hand, is formed of porphyritic eruptive rocks of Mesozoic age, together with sedimentary deposits containing Cretaceous fossils.
The oldest rocks consist of gneiss and schist, penetrated by dikes and bosses of granite, syenite, porphyry and other intrusive rocks.
In the Black River Mountains, at a height of about 1200 ft., there is a clay-slate; and near Midlands, in the Grand Port group of mountains, a chloritic schist occurs about 1700 ft.
This schist is much contorted, but seems to have a general dip to the south or south-east.
At Rammelsberg in the Harz it forms a bed in argillaceous schist, and at Mansfeld in Thuringia it occurs in the Kupferschiefer with ores of nickel and cobalt.
The mining product next in value to coal in 1908 was copper, taken chiefly in Carbon county in a zone of brecciated quartzite underlying schist, the original ore being chalcopyrite, with possibly some pyrite, a secondary enrichment, which has produced important bodies of chalcocite in the upper workings, but these are replaced by chalcopyrite at greater depth.
The rock is a very compact and fine-grained mixture of felspar, quartz and mica, often graduating to mica schist, quartzite and gneiss.
Along the coast lies a belt of granite and schist overlaid unconformably by Cretaceous and Tertiary deposits; inland the mountains are formed chiefly of folded Mesozoic beds, together with volcanic rocks of later date.
This was little more than a small platform of green schist with a sacred tree and an altar, and perhaps later a wooden icon (image), the whole enclosed in a temenos: but, as is proved by a great treasure of objects in precious and other metals, ivory, bone, crystal, paste, glass, terra-cotta and other materials, found in 1904-1905, partly within the platform on which the cult-statue stood and partly outside, in the lowest stratum of deposit, this early shrine was presently enriched by Greeks with many and splendid offerings of Hellenic workmanship. A large number of electron coins, found among these offerings, and in style the earliest of their class known, combine with other evidence to date the whole treasure to a period considerably anterior to the reign of Croesus.
Among the industries of the town are the extraction of oil from the bituminous schist obtained in the neighbourhood, leather manufacture, metal-founding, marble-working, and the manufacture of machinery and furniture.
Part of the rock is schist, but the greater portion limestone, similar in physical qualities to the Carboniferous limestone of Great Britain.
Fuming or Nordhausen Oil of Vitriol, a mixture or chemical com pound of H 2 SO 4, with more or less S03, has been made for centuries by exposing pyritic schist to the influence of atmospheric agents, collecting the solution of ferrous and ferric sulphate thus formed, boiling it down into a hard mass ("vitriolstein") and heating this to a low red heat in small earthenware retorts.
These are formed to a large extent of thick conglomerates which are full of pebbles and boulders of granite and schist.
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.
garnet crystals in schist from the shores of Lochan na Lairige.
mica schist 's, the crystals were moderately good.
The habitat type is developed at high altitudes on calcareous schist.
Find 6 is a fragment of an elongated cobble of a micaceous schist (illus 3: 7 ).
The area is characterized by mainly Dalradian schist and gneiss with intrusions of granite.
After about 3 miles this gives way to crystalline schist 's, mainly mica and some very black graphite.
Examination of cores revealed that the well stopped in fractured schist containing oil.
schist rock formed more than 200 million years ago originating in central Asia.
schist conglomerate capping the basement.
We also found some iron pyrites associated with mica schist 's, the crystals were moderately good.
Now the granite, continuing for long distances, forms the prevailing rock; then, again, it forms the foundation for thick strata of schist and sandstone, itself only appearing in valleys of erosion and river boulders, in rocky projections on the coasts or in the ridges of the mountains....
high, and the prevailing rocks are granite, mica schist, diorite, porphyry and quartzite, the last, where it crops out on the surface, gleaming in the distance like snow.
Find 6 is a fragment of an elongated cobble of a micaceous schist (illus 3: 7).
The western part of the field began producing in 1937 from the fractured schist reservoir.
Material Used All our fountains are crafted by hand from natural Schist rock formed more than 200 million years ago originating in central Asia.
It was accidental in that the objective of the test well was the schist conglomerate capping the basement.
Sulphur is obtained near Apt (Vaucluse) and in a few other localities of south-eastern France; bituminous schist near Autun (Sane-et-Loire) and Buxires (Allier).
Granite is the most widely spread of the crystalline rocks; but dikes of various kinds occur, and gneiss, schist and marble are also met with.
The eyes in both cases were inlaid, those of the lions with red jasper, white shell and blue schist: this imitation of the eyes in stone as well as metal figures was a feature common to both arts, which were at this time assuredly not without direct or indirect connexion.
The mineral wealth of the department is considerable, including coal as well as manganese and bituminous schist; plaster, building stone and hydraulic lime are also produced.
Bergeron has shown that the gneiss and schist which form so much of the chain consist, in part at least, of metamorphosed Cambrian beds.
Various minerals are employed in the manufacture of alum, the most important being alunite or alum-stone, alum schist, bauxite and cryolite.
The oldest rocks consist of granite and schist, penetrated by intrusive dykes, and upon this foundation rest the flat-lying sedimentary deposits, beginning with a sandstone like the Nubian sandstone of Egypt.
These they call respectively the southern schist range, the northern schist range, and the snow range, the last consisting mainly of old crystalline massive rocks.
In the hill country on the borders of Ise, Owari, Mikawa and TOtmi, on the one side, and Omi, Mino and Shinano, on the other, granite frequently forms dark grey and much disintegrated rock-projections above schist and diluvial quartz pebbles.
There are several series of parallel beds, interstratified with quartzite and schist, the most important being the "main reef" series.
These schist ridges rich in quartz show, to a depth of 20 metres, considerable disintegration.
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