What are magmas classified?
Magma is classified as basaltic, andesitic, or rhyolitic, based on the amount of silica it contains. Defines the order in which minerals crystallize from magma. Demonstrates that as magma cools and crystallizes, minerals form in predictable patterns. There are two main patterns (branches) of crystallization.
How is the composition of a magma related to the type of rocks that will form after cooling down?
The composition of magma depends on the rock it was formed from (by melting), and the conditions of that melting. All magmas have varying proportions of elements such as hydrogen, carbon, and sulphur, which are converted into gases like water vapour, carbon dioxide, and hydrogen sulphide as the magma cools.
What is magma composed of?
Magma is a molten and semi-molten rock mixture found under the surface of the Earth. This mixture is usually made up of four parts: a hot liquid base, called the melt; minerals crystallized by the melt; solid rocks incorporated into the melt from the surrounding confines; and dissolved gases.
How is an igneous rock classified?
Igneous rocks may be simply classified according to their chemical/mineral composition as felsic, intermediate, mafic, and ultramafic, and by texture or grain size: intrusive rocks are course grained (all crystals are visible to the naked eye) while extrusive rocks may be fine-grained (microscopic crystals) or glass ( …
How is magma characterized?
Magma is extremely hot liquid and semi-liquid rock located under Earth’s surface. Earth has a layered structure that consists of the inner core, outer core, mantle, and crust. Much of the planet’s mantle consists of magma. This magma can push through holes or cracks in the crust, causing a volcanic eruption.
What happens to the composition of magma as it rises up?
The higher the amount of silica in the magma, the higher is its viscosity. Most felsic magma will stay deeper in the crust and will cool to form igneous intrusive rocks such as granite and granodiorite. If felsic magma rises into a magma chamber, it may be too viscous to move and so it gets stuck.
How does magma differ from lava?
Scientists use the term magma for molten rock that is underground and lava for molten rock that breaks through the Earth’s surface.
What are the top two composition of magma?
Gases in Magmas Gas gives magmas their explosive character, because volume of gas expands as pressure is reduced. The composition of the gases in magma are: Mostly H2O (water vapor) & some CO2 (carbon dioxide) Minor amounts of Sulfur, Chlorine, and Fluorine gases.
How metamorphic rocks are classified?
As with igneous and sedimentary rocks, metamorphic rocks are classified on the basis of texture (grain size, shape, orientation) and mineral composition. Schist is a type of layering or foliation found of metamorphic rocks where minerals large enough to be seen by eye tend to line up all in the same direction.
What is the composition of andesitic magma?
Viscosity of Magmas
| Summary Table | ||
|---|---|---|
| Magma Type | Solidified Rock | Chemical Composition |
| Basaltic | Basalt | 45-55 SiO2 %, high in Fe, Mg, Ca, low in K, Na |
| Andesitic | Andesite | 55-65 SiO2 %, intermediate in Fe, Mg, Ca, Na, K |
| Rhyolitic | Rhyolite | 65-75 SiO2 %, low in Fe, Mg, Ca, high in K, Na. |