noun
definition
A crack or opening, as in a rock.
definition
A groove, deep furrow, elongated cleft or tear; a sulcus.
verb
definition
To split, forming fissures.
Examples of fissures in a Sentence
It often fills cracks and fissures in the rock.
The great interest in connexion with a dwarf West African race of elephant is in relation to the fossil pigmy elephants of the limestone fissures and caves of Malta and Cyprus.
The deposits near Caylus and in Quercy occupy fissures and pockets in Jurassic limestone, and have yielded a remarkable assemblage of the relics of Tertiary mammals and other fossils.
In Scandinavia a thick turpentine oozes from cracks or fissures in the bark, forming by its congelation a fine yellow resin, known commercially as "spruce rosin," or "frankincense"; it is also procured artificially by cutting off the ends of the lower branches, when it slowly exudes from the extremities.
Minute cracks are sometimes produced by the contraction; they are often more or less straight, but in other cases a very perfect system of rounded fissures arises.
Prairie fires or spontaneous combustion have ignited many coal seams. Some have already burnt out; others still emit smoke and sulphurous fumes from the crevices in the hillsides, and through the fissures may be seen the glowing coal and rock.
The free acid is found native in certain volcanic districts such as Tuscany, the Lipari Islands and Nevada, issuing mixed with steam from fissures in the ground; it is also found as a constituent of many minerals (borax, boracite, boronatrocalcite and colemanite).
Artificial soffioni are sometimes prepared by boring through the rock until the fissures are reached, and the water so obtained is occasionally sufficiently impregnated with boric acid to be evaporated directly.
At the close of the Eocene period great eruptions of augite-andesite took place from two fissures which ran along the west coast.
The present volcanoes lie along a line (with offshoots) which runs parallel to the west coast, but some distance to the east of the fissures from which the early Tertiary lavas were poured.
The surface of this table-land slopes from west to east, as indicated by the direction of the drainage of the country, - the great rivers, the Cauvery, Godavari, Kistna and Pennar, though deriving their sources from the base of the Western Ghats, all finding their way into the Bay of Bengal through fissures in the Eastern Ghats.
These fissures with the basalt that solidified in them now form the vast assemblage of dykes which cross Scotland, the north of England and the north of Ireland.
Almost enclosing it on three sides are rose-coloured mountain walls, divided into groups by deep fissures, and lined with rockcut tombs in the form of towers.
A large region was sunken, enormous fissures were opened in the earth, the surface soil was displaced 3 In 1804, the District of Louisiana, in the administrative system of the Territory of Indiana; in 1805, an independent government, renamed the Territory of Louisiana; in 1812, the Territory of Missouri; in 1816, another grade of territorial government.
On the other hand, some rocks in mountain districts, notably the granites, owing to the great quantity of water stored in their numerous fissures or joints, commonly yield a much higher proportion of so-called dry weather flow.
Wherever, below the surface, there are pores or open fissures, water derived from rainfall is (except in the rare cases of displacement by gas) found at levels above the sea determined by the resistance of solids to its passage towards some neighbouring sea, lake or watercourse.
They are the head slits cephalic fissures, " Kopfspalten ") so characteristic of this subdivision (figs.
Certain varieties, notably some from Russia, possess a beautiful metallic sheen, referable to the presence of either microscopic fissures or enclosures.
Valley gravels .border the Thames, and Pleistocene mammalia have been found in fissures in the Hythe beds at Ightham, where ancient stone implements are common.
This is explained by the fact that the Chalk fissures are almost invariably rounded and enlarged by the erosion of carbonic acid carried from the surface by the water passing through them.
The loss of water by leakage through such joints or fissures below the puddle wall may or may not be a serious matter in itself; but if at any point there is sufficient movement of water across the base of the trench to produce the slightest erosion of the clay above it, that movement almost invariably increases.
The bones of Pleistocene mammals, the rhinoceros, mammoth, bison, hyaena, &c., have been found at numerous places, often in caves and fissures in the limestones, e.g.
The shape of the hills and ridges is necessarily influenced by the inclination of the strata, by the relative hardness of different rock-beds, and by the presence of folds and fissures and other lines of weakness.
But beyond the sphere of irrigation, where the land is dependent on the rainfall, there is much rough stony ground broken by great fissures cut by flood-water from the border hills.
In some places the fissures open directly into the air, but in other parts of the district they are covered by small muddy lakes (lagoni).
It likes fibrous peat in fissures of the rocks.
With the true pipes are associated dykes and fissures also filled with diamantiferous blue ground.
The limestones of which they are mostly composed act like a sponge, absorbing the rain-water through their innumerable pores and fissures, and thus storing it up in the interior, afterwards to allow it to well forth in springs at various elevations lower down.
The water from the melted snow forms a small lake at the bottom of the crater, from which it filters through fissures to the heated rocks below and thence escapes as steam or through other fissures to the mineral springs at the mountain's base.
Mountain areas of io,000 acres and upwards, largely covered with moorland, upon nearly imper meable rocks with few water-bearing fissures, yield in temperate climates, towards the end of the driest seasons, and therefore solely from underground, between a fifth and .a quarter of a cubic foot per second per 1000 acres.
In the New Red Sandstone, the Greensand and the upper Chalk, we find the opposite extremes; while the igneous rocks are for the most part only permeable in virtue of the open fissures they contain.
In practice it is usual in chalk formations to imitate artificially the action of such underground watercourses, by driving from the well small tunnels, or " adits " as they are called, below the water-level, to intercept fissures and water-bearing beds, and thus to extend the collecting area.
Imagine for a moment that the sand grains were by any means rendered immobile without change in the permeability of their interspaces; we could then dispense with the iron or brickwork lining of the well; but as there would still be no cracks or fissures to extend the area of percolating water exposed to the open well, the yield would be very small.
Wherever the base of a puddle wall cannot be worked into a continuous bed of clay or shale, or tied into a groove cut in sound rock free from water-hearing fissures, the safest course is to base it on an artificial material at once impermeable and incapable of erosion, interposed between the rock and the puddled clay.
These fissures are in vertical planes stretching entirely across the puddle trench, and reaching in one case, aa, nearly to the highest level at which the reservoir had been worked for seventeen years after the leakage had been discovered.
Thereafter, in papers published by the Cambridge Philosophical Society and the Geological Society of London, he entered largely into mathematical inquiries connected with geology, dealing with the effects which an elevatory force acting from below would produce on a portion of the earth's crust, in fissures, faults, &c. In this way he discussed the elevation and denudation of the Lake district, the Wealden area, and the Bas Boulonnais.
Moreover, there are gigantic fissures, running for several miles, caused by subsidences of the underlying sections.
Sometimes, however, the lava-streams are vomited straight out of gigantic fissures in the earth without any crater being formed.
Evidently the flint has accumulated along fissures, such as bedding planes, joints and other cracks, after the chalk had to some extent consolidated.
The Danube after leaving Donaueschingen flows south-east in the direction of Lake Constance, and below Immendingen a considerable quantity of its waters escapes through subterranean fissures to the river Ach in the Rhine basin.
Each segment is again divided by lateral fissures, which do not extend quite to the posterior border of the organ; of the central lobes thus cut off, the right is rather the larger, and has two fissures in its free border dividing it into lobules.
The entire island is an old coral reef upheaved 200 ft., honeycombed with caves and seamed with fissures.
The round ligament and the remains of the ductus venosus are hidden in the depths of their fissures.
No extra-pigmental eyes; insertion plates with pectinations between the fissures.
An early observation of the diffusion of gases was recorded by him in 1823 when he noticed the escape of hydrogen from a cracked jar, attributing it to the capillary action of fissures.
The number of parts forming such a corolla can be determined by the divisions, whether existing as teeth, crenations, fissures or partitions, or if, as rarely happens, the corolla is entire, by the venation.
Similar residual clays sometimes occur on the surface of areas of limestone in hollows and fissures formed by weathering.
This brown striated coal glows with fissures of opal, brilliant insights of purple amethyst.
They often grow in a tufted habit in small crevices or fissures on rock faces.
At Hele Bay, good crevice communities are to be found in the fissures and crevice communities are to be found in the fissures and crevices in the extensive bedrock on the shore.