What is Iugs classification?
In order to create a sustainable classification of igneous rocks which all geologists might use, an international body was set up by the IUGS: the IUGS Subcommission on the Systematics of Igneous Rocks. The nomenclature for these classifications necessitates only 297 rock names out of the c. 1500 that exist.
Is dacite mafic or felsic?
Dacite is a felsic extrusive rock, intermediate in composition between andesite and rhyolite. It is often found associated with andesite, and forms lava flows, dikes, and, in some cases, massive intrusions in the centres of old volcanoes.
What are plutonic rocks composed of?
igneous rocks
In the restricted sense, plutonic rocks are coarse-grained crystalline igneous rocks formed by consolidation of molten rock material or magma below the Earth’s surface (Latin Pluto, god of the Underworld).
What does Iugs stand for?
The International Union of Geological Sciences (IUGS) is an international non-governmental organization devoted to international cooperation in the field of geology.
How do you do Iugs classification?
The principles are: (1) use descriptive attributes; (2) use actual properties; (3) ensure suitability for all geologists; (4) use current terminology; (5) define boundaries of rock species; (6) keep it simple to apply; (7) follow natural relations; (8) use modal mineralogy; (9) if mode not feasible, use chemistry; (10) …
Why is diorite used in construction?
It is used as a base material in the construction of roads, buildings, and parking areas. It is also used as a drainage stone and for erosion control. In the dimension stone industry, diorite is often cut into facing stone, tile, ashlars, blocking, pavers, curbing, and a variety of dimension stone products.
How does diorite come to the surface?
Diorite formed deep within the Earth’s crust from cooling magma that never made it to the surface. It usually occurs as quite small intrusions often associated with larger intrusions like granite. Slow cooling produces the large crystals.
What is the composition of dacite?
Dacite consists mostly of plagioclase feldspar and quartz with biotite, hornblende, and pyroxene (augite or enstatite). The quartz appears as rounded, corroded phenocrysts, or as an element of the ground-mass. The plagioclase in dacite ranges from oligoclase to andesine and labradorite.
What is dacite composed of?
Like andesite, dacite consists mostly of plagioclase feldspar with biotite, hornblende, augite, or enstatite and generally has a porphyritic structure (scattered larger crystals in a fine-grained groundmass); additionally, however, it contains quartz as rounded, corroded crystals or grains, or as a constituent of the …