I have already pointed out that the volcanic rocks of the large islands of the Solomon Group are geologically ancient.
The Volcanic Rocks, of comparatively recent origin, which have given rise to a succession of trachytes, basalts, and modern lavas.
To that date belong the basalts of Antrim, Mull, Skye, the Faroee Islands, and the older series of volcanic rocksin Iceland.
The deposits in which these plant-remains occur are associated with great sheets of volcanic rocks, which in the Faroee Islands and Iceland reach a thickness of many thousand feet.
The Llandeilo series is represented by a very great thickness of volcanic rocks, varying in composition from basic to acid lavas, with associated pyroclastic rocks.
There are, however, especially in the southern portion, ancient and non-volcanic rocks.
Connection of the Granites and Syenites with the Volcanic Rocks.
Volcanic Rocks, with and without Cones and Craters.
Sodium is a constituent of a variety of felspar which is somewhat abundant in volcanic rocks.
It is a constant ingredient in volcanic rocks, and in several of the most important ores, particularly those of lead, copper and iron.
Volcanic rocks consist of the materials ejected from the craters of volcanoes.
Volcanic rocks differ in texture according also to the rate at which they have solidified.
FLOW LINES are exhibited by volcanic rocks both to the naked eye and under the microscope.
The texture of volcanic rocks depends in part on the degree to which they were distended by the steam which permeated them when in a molten state.
It is a popular belief that the islands of Japan consist for the most part of volcanic rocks.
Gold occurs in quartz veins among schists, paleozoic or volcanic rocks and in placers.
The subject of the differentiation of rock-types in the process of solidification as plutonic or volcanic rocks from a particular magma received much attention from him.
I visited only a part of the north-western side of this island, and this part is entirely composed of volcanic rocks.
In many respects this is a singular deposit; it coats throughout the year the tidal volcanic rocks, that project from the beaches composed of broken shells.
Basalt is the most fusible of volcanic rocks, owing to the augite and magnetite it contains, so that it spreads out with a very slight slope when highly fused.
No volcanic rocks of a more recent period have hitherto been discovered in the island of Cuba; for instance, neither trachytes, dolerites, nor basalts.
The most southern limit of this district is marked by volcanic rocks.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "volcanic rocks" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.
