Which type of melting is responsible for mafic magmas at mid-ocean ridges and why?
Why is so much mafic magma erupted along mid-ocean ridges quizlet?
As the asthenosphere rises, pressure decreases and the rock partially melts (decompression melting). The buoyant, mafic magma rises away from the unmelted residue in the mantle and accumulates in magma chambers in the crust and upper mantle. Mafic rocks are the main type of rocks that form along mid-ocean ridges.
Why does melting occur in magmatism?
Flux melting occurs when water or carbon dioxide are added to rock. These compounds cause the rock to melt at lower temperatures. In this case, water overlying the subducting seafloor would lower the melting temperature of the mantle, generating magma that rises to the surface.
Does partial melting result in predominantly mafic or felsic magma Why?
most rocks melt by partial melting–felsic minerals melt at lower temperatures than mafic minerals, partial melting produces magma more felsic than the source.
Why can we find so many different types of magmas?
There are many different types of magma because there are so many different minerals and chemical components on Earth that could make magma.
What are the three types of magmatism?
There are three basic types of magma: basaltic, andesitic, and rhyolitic, each of which has a different mineral composition.
What is the process of magmatism?
Magmatism is the emplacement of magma within and at the surface of the outer layers of a terrestrial planet, which solidifies as igneous rocks. It does so through magmatic activity or igneous activity, the production, intrusion and extrusion of magma or lava. Volcanism is the surface expression of magmatism.
How important is the process of magmatism?
Magmatism plays a key role in mountain formation, as new ascending magmas produce additional mass and volume to the Earth’s surface and subsurface. Magmas form by partial melting of silicate rocks either in Earth’s mantle, the continental or the oceanic crust.
What are three processes of magma?
There are three principal ways rock behavior crosses to the right of the green solidus line to create molten magma: 1) decompression melting caused by lowering the pressure, 2) flux melting caused by adding volatiles (see more below), and 3) heat-induced melting caused by increasing the temperature.
What are the two processes of magma formation?
Magma is produced by melting of the mantle or the crust at various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots.
What are the three factors that may affect the formation of magma?
The factors that mainly affect in the formation of magma can be summarized into three: Temperature, Pressure and composition.
- Temperature plays a role in the formation of the melts in the magma.
- Pressure can affect the shape and formation of melts.
Which type of magma is most explosive?
Explosive eruptions are favored by high gas content & high viscosity magmas (andesitic to rhyolitic magmas). The explosive bursting of bubbles fragments the magma into clots of liquid that cool as they fall through the air.
What are the special conditions required for the formation of magma?
Wet and Dry Melting In order for magma to form, wet or dry melting of rocks or minerals must occur. Dry melting occurs when minerals or rocks, with no carbon dioxide or water in them, are heated to a specific temperature. This temperature increases as pressure in the Earth’s layers increases.
What two factors determine what type of rock magma will form?
Two factors determine what type of rock forms. The composition of the magma determines if the rock is mafic, felsic, or intermediate. The rate the magma cools determines the texture of the rock.
What three components make up most magmas?
Magma and lava contain three components: melt, solids, and volatiles. The melt is made of ions from minerals that have liquefied. The solids are made of crystallized minerals floating in the liquid melt.
What are the three main types of rocks on Earth?
Part of Hall of Planet Earth. There are three kinds of rock: igneous, sedimentary, and metamorphic. Igneous rocks form when molten rock (magma or lava) cools and solidifies.
What are the 2 types of crust?
Earth’s crust is divided into two types: oceanic crust and continental crust.
What are the 2 main types of igneous rocks?
Igneous rocks are divided into two groups, intrusive or extrusive, depending upon where the molten rock solidifies.
What are the 5 steps of rock cycle?
Metamorphic rocks underground melt to become magma. When a volcano erupts, magma flows out of it. (When magma is on the earth’s surface, it is called lava.)…When the particles are carried somewhere else, it is called erosion.
- Compaction & Cementation.
What are the elements of magma?
Magmas can vary widely in composition, but in general they are made up of only eight elements; in order of importance: oxygen, silicon, aluminum, iron, calcium, sodium, magnesium, and potassium (Figure 3.2.