Igneous-rock Sentence Examples

True granite is an igneous rock made up of mica, feldspar and quartz.

Most interesting among these are the Henry Mountains, formed by the intrusion of molten igneous rock between the layers of sediments, causing the overlying layers to arch up into dome mountains.

F. Magma is intruded into older rocks and crystallizes into a pink igneous rock called granophyre.

These clays are produced by the decomposition of the granite by acid vapours, which are discharged after the igneous rock has solidified ("fumarole or pneumatolytic action").

When this is slow you get bigger igneous rock crystals from magma.

The system is without any notable amount of igneous rock.

Orbicular granite - this igneous rock has an unusual orbicular granite - this igneous rock has an unusual orbicular structure that is sometimes seen in granites and diorites.

Granite is a lighter colored igneous rock containing relatively large crystals of the minerals plagioclase, quartz and alkali feldspars such as orthoclase.

Practically all the remaining area in these islands is occupied by metamorphic schists and gneisses which occur in great variety and with which are associated numerous dikes and masses of intrusive igneous rock.

They are generally of lenticular form, and usually occur in or near the contact of eruptive rocks with schists or slates; the presence of the igneous rock being probably connected genetically with their origin.

The northern coast range is formed by the oldest rocks in the island, consisting chiefly of limestones and marbles with occasional masses of igneous rock.

Stream erosion has dissected these domes far enough to reveal the core of the igneous rock and to give a rugged topography.

The first mode of occurrence is of little significance practically, for the crystalline rocks generally contain too little phosphate to be valuable, though occasionally an igneous rock may contain enough apatite to form an inferior fertilizing agent, e.g.