Table of Contents
What are the most plentiful minerals in peridotite?
The most plentiful minerals in peridotite are: pyroxene and quartz.
What is the main composition of peridotite?
|Dark Gray to Black
|Pyroxene (Bronzite), Olivine
|Upper mantle; sometimes obducted at continent-continent collision zones
What is an essential abundant mineral in the rock peridotite?
Peridotite is an ultramafic plutonic rock containing 40–100% olivine (from peridot, French for olivine); other essential minerals include clinopyroxene and orthopyroxene; common accessory minerals are hornblende, mica, spinel, garnet, feldspar, ilmenite, and sulfides.
What is the most common mineral in an ultramafic rock like peridotite?
Peridotite is a generic name used for coarse-grained, dark-colored, ultramafic igneous rocks. Peridotites usually contain olivine as their primary mineral, frequently with other mafic minerals such as pyroxenes and amphiboles.
Why are silicates the most common minerals?
Because Oxygen and Silicon are the most abundant elements, the silicate minerals are the most common. Since oxygen is the most abundant element in the crust, oxygen will be the major anion that coordinates the other other cations.
How is peridotite rock formed?
Layered peridotites are igneous sediments and form by mechanical accumulation of dense olivine crystals. Some peridotite forms by precipitation and collection of cumulate olivine and pyroxene from mantle-derived magmas, such as those of basalt composition. Basaltic magma is formed from lherzolites in the mantle.
What is peridotite rock?
Peridotite is the general name for the ultrabasic or ultramafic intrusive rocks, dark green to black in color, dense and coarse-grained texture, often as layered igneous complex.
What is characteristic of peridotite?
Peridotite is a very dense, coarse-grained, olivine-rich, ultra- mafic intrusive rock. It is noted for its low silica content, and contains very little or no feldspar ( orthoclase, plagioclase). It is a common component of oceanic lithosphere, and is derived from the upper mantle.
What is the metamorphic rock of peridotite?
Peridotite is the general name for the ultrabasic or ultramafic intrusive rocks, dark green to black in color, dense and coarse-grained texture, often as layered igneous complex. From: Introduction to Mineralogy and Petrology, 2014.
Is peridotite same as peridot?
As nouns the difference between peridotite and peridot is that peridotite is (geology|mineralogy) a rock consisting of small crystals of olivine, pyroxene and hornblende; the major constituent of the earth’s mantle while peridot is a transparent olive-green form of olivine, used as a gem.
Is peridotite a felsic rock?
Compilations of many rock analyses show that rhyolite and granite are felsic, with an average silica content of about 72 percent; syenite, diorite, and monzonite are intermediate, with an average silica content of 59 percent; gabbro and basalt are mafic, with an average silica content of 48 percent; and peridotite is …
What is the most common silicate mineral?
Olivine (see Figures 2a and 2b below) is the most common silicate of this type, and it makes up most of the mantle. Because these minerals contain a relatively high proportion of iron and magnesium, they tend to be both dense and dark-colored.
What kind of minerals are in a peridotite rock?
Peridotite, a coarse-grained, dark-coloured, heavy, intrusive igneous rock that contains at least 10 percent olivine, other iron- and magnesia-rich minerals (generally pyroxenes), and not more than 10 percent feldspar.
Where can you find peridotite in the mantle?
Ophiolites and pipes are two structures that have brought mantle peridotite to the surface. Peridotite is also found in the igneous rocks of sills and dikes. Ophiolites: An ophiolite is a large slab of oceanic crust, including part of the mantle, that has been overthrust onto continental crust at a convergent plate boundary.
What kind of magma forms when peridotite is partially melted?
Basaltic magma forms when peridotite is partially melted. Basalt and peridotite differ in composition because rocks are mixtures of minerals, but each mineral has its own melting temperature. Some minerals start melting earlier and form basaltic magma which migrates upward because of lower density.
How are diamond deposits formed in a peridotite eruption?
These deep-source eruptions are the origin for most of the Earth’s primary diamond deposits. The magma that forms the pipe is thought to ascend rapidly from the mantle, tearing rocks free from the mantle and from the walls of the pipe. These pieces of foreign rock are known as “xenoliths.”.