Serpentine into talc-schist, dolerite into hornblende-schist) by the same agencies.
These are modified forms of basic rocks such as basalt, dolerite and diabase.
Volcanic rocks, locally called "Toadstone," are represented in the limestones by intrusive sills and flows of dolerite and by necks of agglomerate, notably near Tideswell, Millersdale and Matlock.
Volcanic necks may be recognized at Carrick-a-rede, in the intrusive mass of dolerite at Slemish, at Carnmoney near Belfast, and a few other points.
Fair Head is formed of intrusive dolerite, presenting a superb columnar seaward face.
The dolerite of Fair Head sends off sheets along the bedding-planes of these carboniferous strata.
Immense -sheets of dolerite, gabbro, or allied basic rocks indicate eruptive materials intruded as sills or poured out as lavas contemporaneously with the sedimentary formations among which they lie.
It forms part of an intrusive mass which, on the south and west cliffs of the island, has a columnar arrangement and is traversed by dykes of dolerite, most of which run in a northwest direction.
Finally the basic dykes of dolerite, basalt and augite-andesite are abundant and traverse the various sedimentary formations and the granite.
The shores of the Bosporus are composed in the northern portion of different volcanic rocks, such as dolerite, granite and trachyte; but along the remaining course of the channel the prevailing formations are Devonian, consisting of sandstones, marls, quartzose conglomerates, and calcareous deposits of various kinds.
Thus there has been discovered in Babylon a copy of the Behistun (qv.) inscription preserved on a block of dolerite (Weissbach, Babylonische Miscellen.
Above these beds there are layers of dolerite, 15 to 20 ft.
As the rocks lie in a horizontal position, on most of the islands of the group only the basalts or dolerite are visible.
The basalts are submarine flows which formed the basis of the land upon which grew the vegetation which gave rise to the coals; the effusion of dolerite which covered up the Coal formation was subaerial.
The alteration of the fossiliferous Lias by dolerite at Portrush into a flinty rock that looked like basalt served at one time as a prop for the " Neptunist " theory of the origin of igneous rocks.
Probably its original thickness Lough Neagh Tertiary Clays Eocene Basalt and Dolerite Cretaceous Trias, sometimes surmounted by Lower Jurassic Upper Carboniferous Carboniferous was not more than 150 ft., while now only from 40 to loo ft.
The rocks of Tristan da Cunha are felspathic basalt, dolerite, augite-andesite, sideromelane and palagonite; some specimens of the basalt have porphyritic augite.
The most conspicuous member of the Mesozoic group is the sheet of diabase and dolerite, made up of laccolites and sills, which covers most of the central plateau of Tasmania.
They are best developed in the Macdonnell chain in Palaeozoic U Mesozoic Dolerite '&c. ' ® central Australia and in Victoria, where the fullest sequence is known; while they also extended north-eastward from Victoria into New South Wales, where, as yet, no Cambrian rocks have been found.
They are, first, plutonic rocks, especially granite; secondly, volcanic rocks, chiefly trachyte and dolerite; and thirdly, palaeozoic schists.
Gudea was also a great builder, and the materials for his buildings and statues were brought from all parts of western Asia, cedar wood from the Amanus mountains, quarried stones from Lebanon, copper from northern Arabia, gold and precious stones from the desert between Palestine and Egypt, dolerite from Magan (the Sinaitic peninsula) and timber from Dilmun in the Persian Gulf.
Some of his statues, now in the Louvre, are carved out of Sinaitic dolerite, and on the lap of one of them (statue E) is the plan of his palace, with the scale of measurement attached.
In later days, in the time of the Sargonid kings of Akkad or the monarchs of Ur, stones such is granite, basalt, diorite and dolerite were probably brought from the Sinaitic peninsula, if not from the western desert of Egypt, if the Red Sea coast is to be identified, as seems very probable, with Magan, " the place to which ships went," the land whence the Babylonians got some of their first stones for sculpture and architecture.
They are formed of trachyte, dolerite and basalt.