Admin What are plutons classified by?
A plutonic rock may be classified mineralogically based on the actual proportion of the various minerals of which it is composed (called the mode).
What are plutons?
A pluton (pronounced “PLOO-tonn”) is a deep-seated intrusion of igneous rock, a body that made its way into pre-existing rocks in a melted form (magma) several kilometers underground in the Earth’s crust and then solidified.
What are the four classes of plutons?
The most common rock types in plutons are granite, granodiorite, tonalite, monzonite, and quartz diorite.
How are plutonic rocks classified?
Igneous rocks may be divided into two categories. Intrusive or plutonic rocks crystallize from magma beneath the earth’s surface. Extrusive or volcanic rocks crystallize from lava at the earth’s surface. In addition to texture, igneous rocks may are classified according to their chemical composition.
What are three types of igneous bodies?
The most common types of igneous rocks are:
- andesite.
- basalt.
- dacite.
- dolerite (also called diabase)
- gabbro.
- diorite.
- peridotite.
- nepheline.
How is syenite formed?
Syenites are products of alkaline igneous activity, generally formed in thick continental crustal areas, or in Cordilleran subduction zones. To produce a syenite, it is necessary to melt a granitic or igneous protolith to a fairly low degree of partial melting.
Do plutons erupt?
It may represent the magma chamber of an extinct volcano or a magma body that never produced any eruptions. A pluton is a relatively small intrusive body (a few to tens of km across) that seems to represent one fossilized magma chamber.
Where are plutons found?
The magma formed large masses of granite and related rocks called batholiths and smaller blobs called plutons. Some of the rocks that form the larger batholiths can be seen in the Wallowa and Elkhorn Mountains of northeast Oregon and near Grants Pass and Medford in southwest Oregon.
What is the major basis of classification of rocks?
CLASSIFICATION The classification of rocks is based on two criteria, TEXTURE and COMPOSITION. The texture has to do with the sizes and shapes of mineral grains and other constituents in a rock, and how these sizes and shapes relate to each other. Such factors are controlled by the process which formed the rock.