At an elevation of four or five thousand feet there are many springs, which at a short distance form ravines in a soil composed of conglomerates or, further south, of lime.
The origin of such conglomerates is explained by observing the shingle beaches composed of trap- pebbles in modern volcanoes, as at the base of Etna.
It has already been stated (Chapter 15) that the earliest eruptions must have been posterior in origin to those grits and conglomerates of the fresh-water formation of the Limagne which contain no pebbles of volcanic rocks.
Stratified tuffs, with intercalated conglomerates and lavas, are there seen in nearly horizontal layers in sea-cliffs about 300 feet high, near Las Palmas.
The hollows in some of the fragments of vesicular lava of which the breccias andconglomerates are composed are partially filled with calc-sinter, being thus half converted into amygdaloids.
These hills are 1900 feet high above the sea, and consist of conglomerates and sandstones of Upper Devonian age, resting on the inclined edges of grits and slates of Lower Devonian and Upper Silurian date.
Some of these rocks look as if they had flowed as lavas over the bottom of the sea, and enveloped quartz pebbles which were lying there, so as to form conglomerates with a base of greenstone, as is seen in Lumley Den, in the Sidlaw Hills.
The largest number of fossils have been collected from the tuffs and conglomerates and some beds of limestone in the island of Baixo, off the southern extremity of Porto Santo.
They observe that no gold has yet been found in the Permian conglomerates which lie at the base of the Ural Mountains, although large quantities of iron and copper detritus are mixed with the pebbles of those Permian strata.
To these conglomerates succeed argillaceous and calcareous marls and limestones, containing Lower Miocene shells and bones of mammalia, the higher beds of which sometimes alternate with volcanic tuff of contemporaneous origin.
They consist principally of thick limestones above and sandstones and conglomerates below, and thus represent extensive marine submergence of the earth's crust in the Cretaceous where now there are very lofty mountains.
North of the Danube, in Germany as in England, red sandstones, shales andconglomerates predominate, together with beds of gypsum and salt.
The Molasse, in the neighbourhood of the mountains, consists chiefly of conglomeratesand 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 strata consist mainly of conglomerates and sandstones, which, at Gartly and at Rhyme, are associated with lenticular bands of andesite indicating contemporaneous volcanic action.
Conglomerates and rocks of detritus, when considered in the widest sense of the term, manifest characters of a double origin.
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.
The pebbles in the conglomerates are well rounded and water-worn, and consist almost entirely of white clastic quartzites like that of Marble island (Huronian) beds.
The sandstones and conglomeratesare cut by dykes and masses of both acid and basic eruptive rocks.
They supplied a case parallel with that of the conglomerates and sandstones of Angus, and indicated that no extraordinary conditions--no deluges or earth shatterings--had been needed in order to form them.
During this he saw for the first time the Roth-todt-liegende or Lower Permian conglomerates at Halle and at Eisenach, as well as the great lava streams which had supplied them with so much of their materials.
The conglomerates of this ancient series are not pell-mell heaps of angular detritus, violently swept away from the land and huddled promiscuously on the sea-floor.
The most remarkable deposits are theconglomerates of the Dwyka series.
The Ibiquas beds consist of conglomerates and grits.
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 Triassic rocks are mainly red sandstones,--often feldspathic, or arkose, with some conglomerates and shales.
Basal conglomerates and coarse sandstones which must have been laid near shore are succeeded by shaly sandstones, sandy shales, and shales.
Such basal conglomerates are not uncommon among the ancient rocks of the land, and we may know them by their rounded pebbles and larger stones, composed of the same kind of rock as that of the abraded and evened surface on which they lie.
In the vicinity of Campbellton are calcareous and magnesian breccia or agglomerate, hard shales, conglomerates and sandstones of Lower Devonian age.
Fournet, during the carboniferous period, for porphyritic pebbles are found in the conglomerates of the Coal-measure period.
The Magnesian Limestones are absent, and the rocks consist principally of dark-red marl, brown and red sandstones, and calcareous conglomerates and breccias, which are almost entirely unfossiliferous.
The conglomerates of the Old Red Sandstone were now spread out by the beating of an ancient surf, continued through many ages, against the upheaved and broken slates.
In the bosom of the Longmynd rocks, geologists discover conglomerates of rounded stones which bear no resemblance to any rocks now near them.
Morven, the highest hill in Caithness, is formed of gently inclined sandstones and conglomerates resting on an eroded platform of quartz-schists and quartz-mica-granulites.
Above the volcanic series more red sandstones, conglomerates and marls appear.
The plain of Kinross is occupied by the soft sandstones, marls and conglomerates of the upper Old Red Sandstone, which rest unconformably upon the lower division with a strong dip.
Coarse quartz, sandstone, and conglomerates are sometimes found towards the surface.
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.
Gradual decomposition and decay has produced on the base, and produces still, conglomerates of various thickness and extent.
The overlying rocks, which seem to have been poured from the centre of this tract, consist of masses of trachyte and columnar basalt, of pyramids of wacke, and beds of lava and tufwacke, with strata of conglomerates and sandstones.
Towards the south she saw two decaying empires, Austria-Hungary and Turkey, which seemed to be a natural prey for her political and commercial ambitions: two conglomerates of hostile races which are waiting for a master.
Civilization has been threatened in the past by such monstrous conglomerates of heterogeneous nations.
In this group are comprised ordinary sand, the varieties of sandstone and grit, and most conglomerates and breccias.
In the north of England the base of the series consists of pebbly conglomerates and coarse sandstones; and in Scotland generally, the group is composed of massive sandstones with a comparatively feeble development of the calcareous element.
The Upper Old Red Sandstone consists of conglomerates and grits, along with a great series of red and yellow sandstones--the fossils, as before, being fishes and remains of plants.
Finally, we returned to our former ground, near the old conglomerates and the mass of new shells, which ledge the shore of the little harbour.
The material is the normal Secondary formation, sulphates and carbonates of lime supporting modern corallines and conglomerates of shell.
Fine, hard, compact, and purple-blue slate was collected in the ruins; and the red conglomerates on either side of the watercourse suggested that Cascalho had been worked.
Conglomerates occur as channel fills and contain calcium carbonate as cement as do a number of sandstone and siltstone layers in the upper Main Body.
Conglomerates and sandstone are more common in the lower part of the Main Body.
The mudstones and siltstones probably were deposited along flood plains, while the lenticular sands and conglomerates were laid down in stream channels.
None has been found in the basal conglomerates but it is believed to be earliest Eocene.
The member grades laterally basinward from coarse, angular conglomerates to fine mudstone.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "conglomerates" in a variety of sentences. We hope that you will now be able to make sentences using this word.
