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.
Over both sandstone and granite great sheets of lava have been poured, and these, protecting the softer beds beneath from further denudation, now stand up as the high plateaus and hills called harra.
The rocks on the verge of the Kisumu province of East Africa are mainly volcanic (basalt, tuff, lava, kenyte).
An eruption in 1783, with a deluge of lava, destro~ed an extensive forest and overwhelmed several villages.
In the Rudolf province there and are the basalt, lava, tuff and kenyte of the volcanic mineralogy.
There are raised coral beds high up the mountains, and lava occurs in a variety of forms, even in solid flows; but all active volcanic agency has so long ceased that the craters have.
In the northern unfolded region great flows of basic lava lie directly upon the Cambrian and Ordovician beds of Siberia, but are certainly in part of Tertiary age.
Hauran southward forms the main watershed of the peninsula is covered in places by deep beds of lava, which from their hardness have preserved the underlying sandstones from degradation, and now stand up consider ably above the general level.
Volcanic cones still exist in large numbers, and the sheets of lava appear as fresh as any recent flows of Etna or Vesuvius.
The modern cone of the mountain has been built up by suc~ssive discharges of lava and fragmentary materials round a Int of eruption, which lies a little south of the centre of the Tehistoric crater.
Lava is much used for paving-stones in the neighborhood of volcanic districts, where pozzolana (for cement) and pumice stone are also important.
Many of the block mountains of the Great Basin are of complicated internal structure, showing rocks of all ages - slate, limestone, quartzites, granite, multi-coloured volcanic rocks, and large areas of lava overflow.
Near it, in a district called Civita, is a large elliptical area of about 1300 by 380 yds., enclosed by a wall of masses of lava, which is about 28 ft.
Ejections of basaltic lava have been observed on the southern slope vo of this range, extending over wide areas on the plateau itself, over a stretch of more than 600 m.
The numerous deep ravines which indented the des of the prehistoric volcano, and still form a marked feature I the outer slopes of Somma, have on the south side served channels to guide the currents of lava from the younger)ne.
The volcanic fissures that allowed of the upwelling of basalt are represented by numerous dykes, many cutting the earlier lava-flows as well as all the beds below them.
The accumulations of lava gave rise to the plateaus which form almost the whole interior of the county.
Hornaday, Camp Fires on Desert and Lava (London, 1908); Alex.
The magma, or molten lava in the interior of the earth, may be regarded as a mutual solution of various mineral silicates, charged with highly-heated vapour, sometimes to the extent of supersaturation.
According to the proportion of silica, the lava is distinguished as "acid" or "basic."
It will be easier for a while until we get to the Lava fields.
Lava streams and other signs of volcanic action abound, but there has been no igneous activity since the Spaniards took possession.
No evidences of recent lava flows can be found in the interior over the great alluvial plain, the Lower, or the Higher Steppes.
2 Port Lloyd, the chief anchorage (situated on Peel Island), is considered by Commodore Perry - who visited the islands in 1853 and strongly urged the establishment of a United States coaling station there - to have been formerly the crater of a volcano from which the surrounding hills were thrown up, the entrance to the harbour being a fissure through which lava used to pour into the sea.
A vast variety of trinketsin coral, glass, lava, &c.is exported from Italy, or carried away by the annual host of tourists.
Barren Island was last in eruption in 1803, but there is still a thin column of steam from a sulphur bed at the top and a variable hot spring at the point where the last outburst of lava flowed into the sea.
(d)bergusstafelland - Lava plain.
Volcanic activity took place around its shores at the end of the Tertiary or during the Quaternary Age, and great streams of lava cover the Sayan and Khamar-daban mountains, as well as the valley of Irkut.
Throughout the central part of Alexandria the streets are paved with blocks of lava and lighted by electricity.
Nathorst has suggested that the whole of Greenland is a "horst," in the subordinate folds of which, as well as in the deeper " graben," the younger rocks are preserved, often with a covering of Tertiary or later lava flows.'
The very extensive pumice deposits at Neuwied and the lava and other volcanic rocks belong to a more recent epoch.