Table of Contents
- 1 What is the classification of rocks peridotite in terms of color?
- 2 Why is peridotite not considered a mineral?
- 3 What elements are present in the minerals that compose peridotite?
- 4 What minerals is peridotite made up of?
- 5 What kind of rock is a peridotite rock?
- 6 Which is the most monomineralic type of peridotite?
What is the classification of rocks peridotite in terms of color?
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.
Why is peridotite not considered a mineral?
Alteration of Peridotite Peridotite is a rock type that is more representative of Earth’s mantle than of the crust. The minerals that compose it are generally high-temperature minerals that are unstable at Earth’s surface. They are quickly altered by hydrothermal solutions and weathering.
Is peridotite an andesitic?
The average composition of the continental crust is andesitic. Along with basalts, they are a major component of the Martian crust. The name andesite is derived from the Andes mountain range, where this rock type is found in abundance….Andesite.
| Composition | |
|---|---|
| Secondary | Magnetites, biotite, sphene, and quartz |
What elements are present in the minerals that compose peridotite?
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.
Is peridotite an igneous rock?
What minerals is peridotite made up of?
Is peridotite a felsic?
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 kind of rock is a peridotite rock?
Peridotite or Dunite is an intrusive igneous rock, peridotite is coarsegrained and dense. It is light to dark green in color. Peridotite contains at least 40 percent olivine and some pyroxene. Unlike the olivine grains, the pyroxene grains in peridotite have a visible cleavage when viewed under a hand lens.
Where does the magnesium in peridotite come from?
Peridotite is ultramafic, as the rock contains less than 45% silica (SiO4−. 4). It is high in magnesium (Mg2+), reflecting the high proportions of magnesium-rich olivine, with appreciable iron. Peridotite is derived from the Earth’s mantle, either as solid blocks and fragments, or as crystals accumulated from magmas that formed in the mantle.
Which is the most monomineralic type of peridotite?
Ol, Opx, and Cpx represent olivine, orthopyroxene, and clinopyroxene respectively. Dunite is a type of peridotite that is almost monomineralic (more than 90% of it is olivine). Wehrlite contains almost no orthopyroxene but is rich in clinopyroxene and olivine.
How are layered peridotites formed in the mantle?
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.