Dating of amphibolite

How does amphibolite form?

How Does Amphibolite Form? Amphibolite is a rock of convergent plate boundaries where heat and pressure cause regional metamorphism. It can be produced through the metamorphism of mafic igneous rocks such as basalt and gabbro, or from the metamorphism of clay-rich sedimentary rocks such as marl or graywacke.

What type of metamorphism is amphibolite?

Formation of the Amphibolite Rock Amphibolite is a rock associated with the convergent plate boundaries where heat and pressure cause regional metamorphism of mafic igneous rocks such as basalt and gabbro or from the clay rich sedimentary rocks that can be either marl or greywacke.

What is the temperature range of formation of amphibolite?

Amphibolite. The temperature range of formation is usually 400…500 °C 1. Amphibolites are usually either black or dark green, depending on the color of the dominant amphibole. These rocks are usually coarse-grained enough for the individual mineral grains to be seen with the unaided eye.

What are the changes in mineralogy of amphibolite facies?

Changes in mineralogy depends very much on protolith, however, production of abundant garnet and hornblende are most characteristic. Sodic feldspars are oligoclase rather than the albite that dominates at lower T. Biotite and muscovite are both abundant in pelitic rocks of amphibolite facies.

What is amphibolite made of?

Amphibolite is a coarse-grained metamorphic rock that is composed mainly of green, brown, or black amphibole minerals and plagioclase feldspar.

What type of metamorphism is amphibolite?

Formation of the Amphibolite Rock Amphibolite is a rock associated with the convergent plate boundaries where heat and pressure cause regional metamorphism of mafic igneous rocks such as basalt and gabbro or from the clay rich sedimentary rocks that can be either marl or greywacke.

What is the parent rock of amphibolite?

Mafic igneous rocks (e.g., basalts and gabbros) and sedimentary dolomite can be the parent rocks of amphibolite. ... …the rock would become an amphibolite, reflecting a mineralogy composed predominantly of the amphibole hornblende along with plagioclase and perhaps some garnet.

What type of rocks are typically found in the amphibolite facies?

Less intense temperatures and pressures form rocks of the epidote-amphibolite facies, and more intense temperatures and pressures form rocks of the granulite facies. Amphibole, diopside, epidote, plagioclase, almandine and grossular garnet, and wollastonite are minerals typically found in rocks of the amphibolite facies.

What type of rocks are typically found in the amphibolite facies?

Less intense temperatures and pressures form rocks of the epidote-amphibolite facies, and more intense temperatures and pressures form rocks of the granulite facies. Amphibole, diopside, epidote, plagioclase, almandine and grossular garnet, and wollastonite are minerals typically found in rocks of the amphibolite facies.

What are the characteristics of amphibolite facies?

The amphibolite facies is the common high-grade facies of regional metamorphism, and, like the greenschist facies, such rocks are present in all ages from all over the world. Their characteristic feature is the development of the most common amphibole, hornblende, in the presence…

What is the difference between amphibole and biotite in geology?

Biotite, which can be identified easily, is used to identify the lower boundary of this facies; amphibole may also be used as an index mineral to identify the facies.

What are some examples of amphibolite minerals?

Amphibole, diopside, epidote, plagioclase, almandine and grossular garnet, and wollastonite are minerals typically found in rocks of the amphibolite facies.