Gneiss Sentence Examples
Rift valley, overlying a formation of granite, gneiss and quartz.
The rocks of its lower half are mainly granite and gneiss; its upper half is composed of porphyritic greenstone, and a variety of minerals occur.
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.
Bismuth occurs in metalliferous veins traversing gneiss or clay-slate, and is usually associated with ores of silver and cobalt.
Archean rocks - gneiss, schist and granite - cover large areas through which the Nile cuts its way in alternate narrow gorges and open reaches.
The most valuable immediate product of the state's mines and quarries for nearly every year from 1890 to 1908 was building stones of granite and gneiss, which are found in all parts of the state west of the " Fall Line "; the best grades of granite are quarried chiefly in Gaston, Iredell, Rowan, Surry and Wilkes counties.
In Unst the high ground on the west coast consists of gneiss, which is followed eastward by schists of various kinds, then by a belt of serpentine, 2 m.
Nearly the whole of the Riesenkamm and the western portion of the southern chain are granite; the eastern extremity of the main ridge and several mountains to the south-east are formed of a species of gneiss; and the greater part of the Bohemian chain, especially its summits, consists of mica-slate.
Laurentian gneiss forms the greatest mass of the exposed rocks of the country bare of ice.
It is possible that some of these rocks are also of Huronian age, but it is doubtful whether the rocks so designated by the geologists of the " Alert " and " Discovery " expedition are really the rocks so known in Canada, or are a continuous portion of the fundamental or oldest gneiss of the north-west of Scotland and the western isles.
AdvertisementBergeron has shown that the gneiss and schist which form so much of the chain consist, in part at least, of metamorphosed Cambrian beds.
They show a great variety of type made up of slates, quartzites, occasional conglomerates, schists with large masses of intrusive granites and gneiss.
Rising amid the ancient gneiss rocks of the St Gotthard, the Rhine finds its way down to the Lake of Constance between layers of Triassic and Jurassic formation; and between that lake and Basel it penetrates the chalk barrier of the Jura.
The upper Rhenish valley is evidently the bed of an ancient lake, the shores of which were formed by the gneiss and granite of the Black Forest on the one side and the granite and sandstone of the Vosges on the other.
Gneiss and granite occur; Ordovician fossils have been found in the Upper Shan States, and Carboniferous fossils in Tenasserim and near Moulmein.
AdvertisementWest of the volcanic region, nearer to Lake Victoria and the Eastern province, ironstone, granite, gneiss and schistose formations predominate, with phonolite in places.
In the Eastern province the rocks are mainly quartz, gneiss and granite, with sandstone in Busoga, basalt round Mt Elgon, slate (Busoga) and iron- g stone (Busoga and Bukedi).
Geologically, they have also been differentiated as the Gneiss Islands and the Trap Islands.
The Outer Hebrides being almost entirely composed of gneiss the epithet suitably serves them, but, strictly speaking, only the more northerly of the Inner Hebrides may be distinguished as Trap Islands.
The several ranges of the Cordillera show very different types of structure and were formed at different ages, the Selkirks with their core of pre-Cambrian granite, gneiss and schists coming first, then the Coast Ranges, which seem to have been elevated in Cretaceous times, formed mainly by a great upwelling of granite and diorite as batholiths along the margin of the continent and sedimentary rocks lying as remnants on their flanks; and finally the Rocky Mountains in the Laramie or early Eocene, after the close of the Cretaceous.
AdvertisementThe configuration of the hills is mainly conical and the geological formation consists of gneiss, granite (in the south) and red sandstone.
As in the neighbouring mainland of Caithness, these rocks rest upon the metamorphic rocks of the eastern schists, as may be seen on Pomona, where a narrow strip is exposed between Stromness and Inganess, and again in the small island of Graemsay; they are represented by grey gneiss and granite.
The foreign boulders of granite, gneiss, &c., found in the coalmeasures of some districts, are quite as likely to have been dropped by rafts of vegetation as to have been carried by floating icebergs.
The oldest rocks are gneiss, schist and quartzite, the schist often containing gold.
Among the commonest associates of the diamond are quartz, topaz, tourmaline, rutile, zircon, magnetite, garnet, spinel and other minerals which are common accessory constituents of granite, gneiss and the crystalline schists.
AdvertisementChaper found diamond with corundum in a decomposed red pegmatite vein in gneiss.
They consist chiefly of gneiss and schist, with granite and other eruptive rocks.
Between the Palaeozoic area near Ottawa, and Georgian Bay to the north of the region just referred to, there is a southward projection of the Archaean protaxis consisting of granite and gneiss of the Laurentian, enclosing bands of crystalline limestone and schists, which are of interest as furnishing the only mines of "Old Ontario."
Their geological formation is metamorphic gneiss, veined with felspar and quartz, and interspersed with reddish porphyrite.
The Monti Peloritani at the north-eastern extremity of the island consists of gneiss and crystalline schists; but with this exception the whole of Sicily is formed of Mesozoic and later deposits, the Tertiary beds covering by far the greater part.
The island is composed of marble, though gneiss and mica-schist are to be found in a few places.
It is composed of gneiss, is generally rather flat, save in the west where Ben Hogh reaches a height of 339 ft., and has several lakes.
Dispersed over all parts of the western Highlands, they are most numerous in the north-west, especially in the Outer Hebrides and in the west of the shires of Ross and Cromarty and Sutherland, where the surface of the Archean gneiss is so thickly sprinkled with them that many tracts consist nearly as much of water as of land.
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.
Eastward of the Archean gneiss in the west of Sutherland the effect of enormous underground pressure has been to upraise masses of the ancient gneiss and Torridonian sandstone and thrust them westward over the younger rocks.
Above the Archean gneiss lies a series of red and chocolate-coloured sandstone (Torridon sandstone), which form a number of detached areas from Cape Wrath down the seaboard of the shires of Sutherland and Ross and Cromarty, across Skye, and as far as the island of Rum.
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.
These mountains, consisting of various sorts of gneiss, intrusive granite and gabbro, have been formed partly by faulting but mainly by erosion, the lines of which have been determined by the presence of faults or the presence of relatively soft rocks.
In the south, where they are known as the Dharwar series, they form long and narrow bands running from north-north-west to south-south-west across the ancient gneiss; and it is interesting to note that all the quartz-reefs which contain gold in paying quantities occur in the Dharwar series.
The oldest rocks exposed are gneiss, talc-schist and serpentine, with intrusive masses of gabbro and diabase.
In the north of Bundelkhand the prevailing rock is gneiss and quartz.
The rock formation is gneiss.
The greater part of the mass is composed of gneiss and schists.
Three divisions are distinguished by some authors - the grey gneiss, the red iron gneiss and the granulite.
The red iron gneiss prevails in western Sweden in the provinces of Vermland, Skaraborg, Elfsborg, and down to the province of Kristianstad.
The formation is very uniform in its character, the gneiss having a red colour and containing small granules of magnetite, but, nevertheless, not a single iron mine belongs to this region.
The rock is a very compact and fine-grained mixture of felspar, quartz and mica, often graduating to mica schist, quartzite and gneiss.
The iron deposits occur in more or less fine-grained gneiss or granulite (Gellivara, Grangesberg, Norberg, Striberg), or separated from the granulite by masses of augitic and amphibolous minerals (gronskarn), as in Persberg and Nordmark.
Besides the crystalline gneiss and halleflinta there are also sedimentary deposits which are believed to be of pre-Cambrian age.
Large masses of granite are found in many parts of Sweden, in Kronoberg, Orebro, Goteborg, Stockholm, &c. Sometimes the granite graduates into gneiss; sometimes (as north of Stockholm) it encloses large angular pieces of gneiss.
West of the Cordillera Oriental, where special conditions prevail, a great desert plateau stretches entirely across one corner of the republic. Apart from the Andean system there is a group of low, broken, gneiss ranges stretching along the east side of Bolivia among the upper affluents of the Mamore and Guapore, which appear to belong to the older Brazilian orographic system, from which they have been separated by the erosive action of water.
There is no axial zone of gneiss, but intrusions of granite and other plutonic rocks occur, and the famous ore deposits are found chiefly near the contact of these intrusions with the schists.
The Mongolian or Great Altai, on the other hand, consists mainly of gneiss and Archaean rocks.
Geologically they belong to the primitive formation - granite, compact dark blue slate, gneiss and syenite.
The mines there occur in gneiss and schists, which are probably of Archean age; the lode has in places been worked for a width of over 200 ft.
The Central Cordillera is the direct continuation of the Eastern Cordillera of Ecuador, and is formed chiefly of gneiss and other crystalline rocks, but sedimentary deposits of Cretaceous age also occur.
Geological research shows that the land surrounding the lake consists of gneiss, quartz and schistose rocks, covered, in the higher regions, with marl and red clay, and in the valleys with a rich black loam.
Geologically, the Erzgebirge range consists mainly of gneiss, mica and phyllite.
They form an interesting and bleak moorland between Cookstown and Omagh, extending north-eastward into Slieve Gallion in county Londonderry, and consist fundamentally of mica-schist and gneiss, affected by earth-pressures, and invaded by granite near Lough Fee.
These occurrences of granite, with that of Leinster, in connexion with the folding of the Silurian strata, make it highly probable that many of the granites of the Dalradian areas, which have a similar trend and which have invaded the schists so intimately as to form with them a composite gneiss, date also from a post-Silurian epoch of earth-movement.
These consist mostly of granite and gneiss, but in the north-central section there is trap-rock, and in the south-east section some slate.
The gneiss is mostly grey, but occasionally pinkish, its essential constituents (felspar and quartz) being almost always associated with dark mica (biotite) and hornblende in variable quantity.
Almost the whole of this region is covered by a red soil, often of great thickness, which resembles and is often described as " clay," but is really decomposed rock, chiefly gneiss, reddened with oxidized magnetite.
In the Archean region the gneiss is very often found passing into granite, but certain granitic masses have a sufficiently distinct character.
The main ridge of the formation, consisting of gneiss, granite and red sandstone, runs from a point opposite Miltenberg, in a north-westerly direction to the source of the Kinzig near Schliichtern - a distance of 45 m.
The most certain representatives of the Archean are the gneiss and schists of the Dove river and the upper Forth, and the hornblende-schists, which are exposed in the river valleys on the margins of the central plateau.
Volcanic action is still going on in these latitudes, as the glaciers are at times covered by ashes, but the predominant rocks to the east are the Tertiary granite, while to the west gneiss, older granite and Palaeozoic rocks prevail.
Gneiss is seldom met with, but there are crystalline rocks, belonging chiefly to the pre-Cordillera of the eastern and to the Cordillera de la Costa on the western side.
There is no continuous band of ancient gneiss, nor indeed of any beds older than the Jurassic. There is very little over-folding or faulting, and the structure is that of the Jura mountains rather than of the Alps.
The greater part of the island seems to be formed of gneiss and other crystalline rocks.
The substrata are mostly sandstone of various formation, and granitic gneiss, of which the rocks are mainly composed.
The church's main point of interest are the three tombs carved in black gneiss depicting knights in armor.
Natural soils have developed from a parent material consisting of glacial till derived from granite and granite gneiss.
The hornblende gneiss is dark in color and occurs as pods and bands within the lighter colored gneiss.
The area is characterized by mainly Dalradian schist and gneiss with intrusions of granite.
This county includes in the north an area of the gneiss that is discussed under county Donegal, and, west of Omagh, a metamorphic region that stretches in from the central axis of Tyrone.
Yell is formed of coarse gneiss and granitic rocks.
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.
Ungava includes much of the lower portion of Labrador, with a rim of recent marine deposits along its western coast, but the interior has the usual character of low rocky hills of Archean rocks, especially granite and gneiss, with a long band of little disturbed iron-bearing rocks, resembling the Animikie, or Upper Huronian of the Lake Superior region, near its eastern side.
The Finland rappa-kivi, the Serdobol gneiss, and the Pargas and Rustiala marble (with the so-called Eozoon canadense) yield good building stone; while iron, copper and zinc-ore are common in Finland and in the Urals.
Large sheets of muscovite, such as are of commercial value, are found only in the very coarsely crystallized pegmatite veins traversing granite, gneiss or micaschist.
The hills are of primary formation, with fine masses of contorted gneiss.
Gneiss, granite and quartz - the decomposed granite giving the red " African " clay - are the leading features in the formations of the Northern province, of Buganda, and of the Western province, with some sandstone in the littoral districts of Buganda and in Ankole, and eruptive rocks.
The graphite found in granite and in veins in gneiss, as well as that contained in meteoric irons, cannot have had such an origin.
Alluvial loams occupy the narrow river valleys; but the most common soil of the section is that formed from gneiss with a large per cent.
They consist of gneiss, mica-schist, quartzites, crystalline limestones and conglomerates.
In the mountain region the soil is mostly a sandy loam composed of disintegrated granitic gneiss and organic matter; on the lower and more gentle slopes as well as in the valleys this is generally deep enough for a luxuriant vegetable growth but on the upper and more precipitous slopes it is thin, or the rocks are entirely bare.
This vast area, shaped like a broad-limbed V or U, with Hudson Bay in the centre, is made up chiefly of monotonous and barren Laurentian gneiss and granite; but scattered through it are important stretches of Keewatin and Huronian rocks intricately folded as synclines in the gneiss, as suggested earlier, the bases of ancient mountain ranges.