The roughness of the trachytic blocks, however, rendered a slip impossible.
And now the great trachytic dome, towering in the translucent air, was the marking feature.
The cave, a mere hole in the trachytic lava, opens to the east with an entrance some four feet wide.
It is apparently basalt, as we may expect in the lower levels before reaching the trachytic region.
In the clear winter-air we could distinctly trace the bold contour of the upper heights tipped by the central haystack, El Nublo, a giant trachytic monolith.
The talus now narrowed; the side-walls of darktrachytic blocks pinching it in.
The French geologist found that the vesicles or pores of the trachytic masses were lengthened out in the several directions in which they would have flowed if they had descended from the axis of a cone once occupying the centre of the crater.
The same traveller supposes, although he found no limestone or trace of fossils in any of the rocks of Teneriffe, that the alternating trachytes and trachytic conglomerates originated beneath the sea.
But lavas occur of an intermediate composition between the trachytic and basaltic, which from their color have been called graystones.
When basaltic islands and trachytic rocks rise on fissures, friction of the elevated rock against the walls of the fissures causes the elevated rock to be inclosed by conglomerates composed of its own matter.
Water and mud, which flow not from the crater itself, but from the hollows in the trachytic mass of the mountain, can not, strictly speaking, be classed among volcanic phenomena.
In this description, the vesicular distension of the earth's crust (a stage at which many trachytic mountains have remained) is very well distinguished from the eruption itself.
The whole range is for the most part composed of various kinds of trachytic conglomerate.
The reason of this is, that felspar is lighter than hornblende, and probably rises to the surface of the lava mass at the volcanic focus, and the basaltic lava is therefore reserved till the trachytic has been thrown off.
When both kinds are products of the same eruption, the trachytic lava is thrown out first, and the basaltic last.
Trachytic rocks: their singular decomposition by steam of high temperature.
Dree, is worthy of further consideration, as throwing light on the separation of the trachytic and basaltic series of lavas.
In the central part of the island there is a spot, where steam is constantly issuing in jets from the bottom of a small ravine-like hollow, which has no exit, and which abuts against a range of trachytic mountains.
As is so often the case with trachytic formation, no stratification is here apparent.
Can it be due to a less perfect degree of fluidity, which is generally supposed to be characteristic of the allied trachytic lavas?
From this place to the mines the rocks were soft decomposing dolerites, with many harder bands of felsite, and, occasionally, plains composed of more recent trachytic lavas.
Chimborazo is very likely not a solid mountain; trachyticvolcanoes are supposed to be full of cavities.
The upper (Magdala group) contains much trachytic rock of considerable thickness, lying perfectly horizontally, and giving rise to a series of terraced ridges characteristic of central Abyssinia.
It stands partly on level ground, partly on a declivity, and above it rises a precipitous trachytic rock (400 ft.
Alunite occurs as seams in trachytic and allied volcanic rocks, having been formed by the action of sulphureous vapours on these rocks.
It may easily be conceived what vast quantities of elastic gases, what masses of molten matter accumulated beneath its solid surface whilst no exit was practicable after the cooling of the trachytic crust.
Its double cone forms the limit of a trachytic belt which stands out distinctly in the mountain system of the island.
To these succeeded during the Pliocene epoch still more highly silicated rocks of trachytic type, consisting of sanidine and oligoclase trachytes.
This mountain appears to be formed mainly of trachytic matter.
Domite is the name applied to the trachytic rocks of the Auvergne district and the Puy de Dome particularly.
Amongst the group are trachytic domes such as the Mountain of Tobreonu in the Society Islands, rising to a height probably not inferior to that of Etna, with extremely steep sides, and holding a lake on its summit.
They consist of a trachytic ground-mass in which grains or crystals of quartz and sanidine, with other accessory minerals, are imbedded.
Many of the trachytic beds are brecciated and highly columnar; sedimentary beds are also interstratified with those of volcanic origin.
They rise from the place where the trachytic rocks overlap the granite, and were obtained by boring to the depth of from 82 to 92 ft.
At about a third of the way the Dordogne is crossed, and shortly afterwards is passed the ravine of the Egravats, formed by a landslip of the trachytic mountain, the Roc de Cuzeau, 5706 ft.
From Le Beage the trachyticmountain of +Mezenc+ (pronounce Mezing) is visited.
This peculiar opalescent chalcedony occurs as concretions, sometimes of large size, in the trachytic lavas of Mexico.
This central mass consists principally of a greyishtrachytic porphyry, in some places rich in veins of silver-ore.
The conglomerates and tuffos at their feet, and partly on their terraces and tops, are of trachytic nature, and sometimes pierced through by small dikes of basalt.
Veins of ochre and clay, holes filled with scoria, with intrusions of larger or smaller fragments of various rocks and minerals, and a kind of stratification, are the principal features of this trachytic formation.
Basaltic and trachytic hills, either isolated or in chains, rise at a distance of about half a mile from the sea-shore, which is winding and shelving.
Poeppig, is a lofty basaltic crater, having a trachytic cone rising up in its centre to an elevation of 8672 feet.
Hochstetter, the hornblendic phonolithe rock found there, far from a volcanic crater, but with trachytic dykes and basaltic amygdaloid.
The trachytic rock on the summit has broken through the Jurassic strata, in which Leopold von Buch has ascertained, from heights of 9000 feet, the existence of Exogyra couloni, Trigonia costata, and Ammonites biplex.
In New Zealand, numerous regions abound in basaltic and trachytic rocks.
We have as yet no certain intelligence as to the geology of the entire longitudinal auriferous valley of the Sacramento River, (where a trachytic crater, in a state of disintegration, is known as the Butt of Sacramento).
Some of the trachytic lavas are said to abound with crystals of albite.
There are phonolites of basaltic strata (the most anciently known) and phonolites of trachytic strata (Andes of Mexico).
These garnets re-appear in the trachytic porphyries that crown the celebrated metalliferous mountain of Potosi, and in the black and pyroxenic masses of the small volcano of Yana-Urca, at the back of Chimborazo.
Trachytic knot of Anahuac, parallel with the Nevados and the burning volcanoes of Mexico.
A specimen of the tuffs shows, besides fragments of altered rhyolitic or trachytic rocks, portions of decomposing pumice, the vacuoles and tubular cavities of which are filled with alteration products.
Similar rocks, showing pyrites, occur amongst the blocks of Vunimbua River; but here the rhombic pyroxene is mostly converted into bastite, and the groundmass is in part trachytic as well as felsitic in texture.
In the coast district between Tutu Island and the village of Naua, 3½ miles to the east, the same altered coarse pumiceous and trachytic tuffs, occasionally bedded and dipping W.
In connection with the quartz-porphyries and trachytic rocks which also occur in Vanua Levu, it should be observed that Mr. Andrews describes a rhyolite from Suva in Viti Levu.
Although not extensive they are valuable from their reference to his discovery of trachytic and rhyolitic rocks as well as acid pumice-tuffs in the island.
They have evidently, in part at least, been derived from compact rhyolitic and trachytic rocks, and are probably in some measure the products of marine erosion.
It is composed of a much weathered whitish trachytic rock, which in appearance affords no promise of polarity, but has the power of repelling the magnetic needle 2° to 3°.
The Puy-de-Dôme, one of the most remarkable volcanic domes in Auvergne, presents another fine and very striking example of an eruptive trachytic rock.
In America it is principally represented by some immense cones, superposed in the chain of the Andes; the colossal Chimborazo being one of those trachytic cones.
On the banks of the Rhine and in Hungary the trachyticformation presents itself in features identical with those which indicate it in France.
The strictly trachytic portion of the group rises in the centre, and is composed of high mountains, throwing off spurs, which gradually decrease in height, and terminate in plateaux more or less inclined.
Rose, as well as from my own measurements) to the various claystone and greenstone porphyries, and to the trachytic lavas of the Cordillera.
There are other varieties, with an almost truly trachytic base, full of little angular vesicles and crystals of glassy feldspar; and there are beds of black perfect pitchstone, as well as of a concretionary imperfect variety.
According to Meyen, there is a hill of pumice high up the valley of the Maypu, and likewise a trachytic formation at Colina, a village situated north of St. Jago.
This ridge has been subjected to excessive violence; trachytic lava has burst from it, and hot springs yet flow at its base.
The mineral formations in which this metal occurs, are the crystalline primitive rocks, the compact transition rocks, the trachytic and trap rocks, and alluvial grounds.
The native gold is disseminated in ores of sulphuret of silver, which occur in small masses and in veins in a decomposing felspar rock, amid a conglomerate of pumice, constituting a portion of the trachytic formation.
The enormous eruptions of the trachytic lava cover a continuous area of more than five thousand square miles.
These form a narrow pay streak from one to eighteen inches wide, and the remainder is filled with a gangue rock, generally of a trachytic formation.
In Porto Santo the trachytic rocks bear a much greater proportion to the basaltic than in Madeira.
The trachytic rocks are small in quantity compared with those of the basaltic class.
Greystone lavas are intermediate in composition between basaltic and trachytic lavas.
In the Lower Eifel, eruptions of trachytic lava preceded the emission of currents of basalt, and immense quantities of pumice were thrown out wherever trachyte issued.
The igneous rocks of the Westerwald, and of the mountains called the Siebengebirge, consist partly of basaltic and partly of trachytic lavas, the latter being in general the more ancient of the two.
This deposit is followed by 5 b, which is similar to 5, and 5 c similar to thetrachytic breccia 5 a.
Daubeny's description of the decomposition of trachytic rocks in the Solfatara, near Naples, by sulphuretted hydrogen and muriatic acid gases.
It has been remarked that in Auvergne, the Eifel, and other countries where trachyte and basalt are both present, the trachytic rocks are for the most part older than the basaltic.
We find several hills in the neighbourhood of Aurillac composed of such materials, for the height of more than 200 feet from their base, the whole sometimes covered by rocky currents of trachytic or basaltic lava.
Antonio, which are entirely composed of trachytic rocks.
The outbursts of porphyry and trachytic domes, so characteristic of the high crests of the Cordilleras, impart a physiognomy quite distinct from that presented by the mountains of Europe.
Chimborazo is very likely not a solid mountain: trachytic volcanoes are supposed to be full of cavities.
They were imbedded in the middle of an unstratified cliff, four hundred feet high, of very compact silt or trachytic clay, free from stones, and resting on a hard quartzoze sandstone.
The mountain Labo appears from its bell-shape and the strata exposed in the river bed to consist of trachytic hornblende.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "trachytic" in a variety of sentences. We hope that you will now be able to make sentences using this word. Other words: craggy; crystal; crystalline; gravelly; gritty; monolithic; pebbly; rocky; sandy; shingled; stony
