noun
definition
The molten rock ejected by a volcano from its crater or fissured sides.
definition
Magma.
definition
A shade of red, named after the volcanic lava.
Examples of lava in a Sentence
Great streams of lava flowed from the crater in ancient times.
The lava is a basic augiteandesite.
Less than a days' march north of here is a lava field.
The different kinds of lava are more fully described in the article Volcano.
The Columbia plateau consists of horizontal beds of lava having a total thickness of several thousand feet, and its surface has a general elevation of tow to 2000 ft.
The term lava is applied by geologists to all matter of volcanic origin, which is, or has been, in a molten state.
The islands have large (unworked) supplies of pumice, sandstone, sulphur, gypsum, alum and mineral-paint ochres, and some salt, kaolin and sal-ammoniac, but otherwise they are without mineral wealth other than lava rocks for building purposes.
The Columbia river has entrenched itself in a canyon-like valley around the northern and Western side of the lava plains; Snake river has cut a deeper canyon farther south-east where the plains are higher and has disclosed the many lava sheets which build up the plains, occasionally revealing a buried mountain in which the superposed river has cut an even narrower canyon.
The lava plains are treeless and for the most part too dry for agriculture; but they support many cattle and horses.
The amount of volcanic material, consisting of both pyroclastic material and lava flows, is great.
The centre of the island consists of a desert field of lava streams, about 1600 ft.
Igneous rocks, whether lava flows or pyroclastic ejections, are less important in the Quaternary than in the Tertiary, though volcanic activity is known to have continued into the Quaternary.
The island is entirely volcanic, and the soil is finely disintegrated lava.
Broken black lava forms the beach, and blocks of it are the universal building material.
Chu-sung, the capital and seat of government, a few miles from Port Pelto, has a black lava wall 25 ft.
Even at the time when they were first known to Europeans, they had stone and lava hatchets, shark's-tooth knives, hardwood spades, kapa cloth or paper, mats, fans, fish-hooks and nets, woven baskets, &c., and they had introduced a rough sort of irrigation of the inland country with long canals from highlands to plains.
Subsequently, in the Tertiary period, there were two enormous outpourings of volcanic material - first andesitic lava, and later, after a long interval of quiet, rhyolitic - which nearly half filled the basin, converted it into a plateau and broke up the mountain rim.
Lava streams are seldom emitted from these volcanoes, the material erupted consisting chiefly of ash and scoriae, which are spread over a very wide extent of country.
In the third, after the Campagna, by a great general uplift, had become a land surface, volcanic energy found an outlet in comparatively few large craters, which emitted streams of hard lava as well as fragmentary materials, the latter forming sperone (lapis Gabinus) and peperino (lapis Albanus), while upon one of the former, which runs from the Alban Hills to within 2 m.
At Acireale the lava has assumed the prismatic or columnar form in a striking manner; at the rock of Aci it is in parts spheroidal.
The Grotte des Chevres has been regarded as an enormous gas-bubble in the lava.
The remarkable stability of the mountain appears to be due to the innumerable dikes which penetrate the lava flows and tuff beds in all directions and thus bind the whole mass together.
This eminence is itself due to an outflow of lava from that mountain, during some previous eruption in prehistoric times, for we know from Strabo that Vesuvius had been quiescent ever since the first records of the Greek settlements in this part of Italy.
Millstones and pumice were also exported, but for the former the more gritty lava of Rocca Monfina was later on preferred.
No good building stone was at hand; and the public as well as private edifices were constructed either of volcanic tufa, or lava, or Sarno limestone, or brick (the latter only used for the corners of walls).
Grey tufa period; ashlar masonry of tufa, coated with fine white stucco; rubble work of lava.
Certain flat oval nodules from a decomposed lava (augite-andesite) in Uruguay present a cavity lined with quartz crystals and enclosing liquid (a weak saline solution), with a movable air-bubble, whence they are called "enhydros" or water-stones.
In 1909 the mountain was in eruption and huge streams of lava were ejected.
At the foot of the eastern slope stretches a vast lava field - the " malpays 'f (malapais) of Atlachayacatl - which, according to Humboldt, lies 60 to 80 ft.
They are formed from a grey trachytic lava found at the east end of the island.
The lava rocks near the houses are carved into the resemblance of various animals and human faces, forming, probably, a kind of picture writing.
Where lava has been piled up in successive nearly horizontal sheets, with occasional layers of tuff or other softer rock between them, it offers conditions peculiarly favourable for the formation of escarpments, as in the wide basalt plateaus of the Inner Hebrides.
The two leading types of volcanic areas are the plateaus, in which sheets of porphyrites, basalts and even trachytes were emitted, sometimes with wide discharge of volcanic ashes, and the puys, or isolated vents, or scattered groups of vents, which discharged comparatively a small amount of lava and ashes.
In the Isle of Eigg, for example, the basalts had already been deeply eroded by river-action and into the river-course a current of glassy lava (pitch-stone) flowed.
Denudation has continued active ever since, and now, owing to greater hardness and consequent power of resistance, the glassy lava stands up as the prominent and picturesque ridge of the Scuir, while the basalts which formerly rose high above it have been worn down into terraced declivities that slope away from it to the sea.
It is built chiefly of lava, and stands on the lava stream of 1631, which destroyed two-thirds of the older town.
The town has shipbuilding yards and lava quarries.
Its eruptions are not on a grand scale, but small outbursts of lava and explosions of steam occur at frequent intervals, and at longer intervals more violent explosions in which the molten rock is thrown 2000 ft.
Moreover, the calcined matter resembling white sand which covers its sides below the snow-line, extensive beds of lava, and the issue of streams of hot water from its northern side, seem to confirm the deduction that Chimborazo is an extinct volcano.
The island is of volcanic origin, a fragment of an ancient stream of lava.
It is a large volcanic region, entirely covered with lava and other igneous rocks.
The theatre, covered by a stream of lava, and built partly of small rectangular blocks of the same material, though in the main of concrete, has been superimposed upon the Greek building, some foundations of which, in calcareous stone, of which the seats are also made, still exist.
To the north, in the Piazza Stesicoro, is the amphitheatre, a considerable portion of which has been uncovered, including the two corridors which ran round the whole building and gave access to the seats, while a part of the arcades of the exterior has been excavated and left open; the pillars are made of blocks of lava, and the arches of brick.
Their excellent preservation is accounted for by their burial under the lava.
Through these, again, pierce other granites in dikes or lava flows, and overlying the whole are limestones of Cretaceous and Tertiary age, themselves cut through by later volcanic eruptions.
But its most notable article of commerce is that of mill-stones, made of lava and tufa-stone, a product much used by the Dutch in the construction of their dykes.
The matter transported consisted of soil of various kinds - sand, ashes, fragments of lava, pozzolana and whitish pumice, enclosing grains of uncalcined lime, similar in every respect to those of Pompeii.
North and south of Alid extends a vast lava field.
Streams of lava completely destroyed several villages and injured others, as well as the town of San Fernando.
The lava flow extended more than 7 m.