What is Magma Made Of?

What is Magma Made Of?
In this Buzzle article, we will try to answer one of the basic questions in the field of geological studies, what is magma made of. If experts are to be believed, its composition depends on various geological processes, including fractional crystallization and contamination.
Magma is the molten form of rock, stored deep beneath the Earth's surface. The temperature of this hot fluid ranges from 1292 - 2372 °F. At this temperature, it has the ability to melt the surrounding rock structures to produce more magma.

Magma can escape to the surface of the Earth as a result of volcanic eruptions. The volcanoes that emit ash are known as 'explosive volcanoes', while those which emit lava are termed as 'effusive volcanoes'. The explosions in these volcanoes are attributed to the intense pressure that is formed due to various gases within them.

How is Magma Formed?

Temperature and pressure rise with depth, eventually reaching a level where they can even melt the strongest rock and turn it to a liquid form. This liquid rock is referred to as magma. Enormous heat, which is sufficient enough to melt the rocks, is also generated when two huge rock masses rub against each other. The molten material, which already exists in the outer core of the planet, travels to the other parts through cracks and fissures. In the process, it also melts the solid rock walls that come in contact with it.

Due to intense pressure, high temperature, density change, and mixture of gases in the interior of the Earth, this molten rock material is pushed towards the surface of the Earth via cracks in the Earth's crust. Once it comes to the surface, it is known as lava.

What is Magma Made Of?

Magma is primarily made up of elements like ...

As the amount of oxygen and silica in the molten matter is high, it is ideal to classify it into different types depending on its silica content. The four different types of magma, broadly categorized on the basis of silica content, are Ultramafic, Mafic, Intermediate, and Felsic.

Ultramafic magma is extremely low in silica, with less than 45 percent of the same, but rich in heavier elements like iron and magnesium. It can have a temperature of about 2732 °F. It has very low viscosity and thus, its eruptive behavior is gentle.

Mafic magma is relatively poor in silica content, with less than 50 percent of it, but rich in heavy elements like iron, magnesium, and calcium. It can have a temperature as high as 2372 °F. It is very explosive in nature.

Intermediate magma contains 60 percent silica, but the magnesium and iron content in it is very low. Very explosive in nature, its temperature can be as high as 1832 °F.

Felsic magma contains more than 70 percent silica content, but its iron and magnesium content is negligible. Highly viscous, its temperature can be as high as 1652 °F.

Note: The viscosity of magma is defined as its resistance to flow. It has a direct relationship with its silica content, i.e., more the silica content, greater the viscosity.

The composition of magma undergoes certain changes as it ascends to the surface. As it makes its way up, it melts the rock structures surrounding the upward flow and integrates the elements present in them. This, in turn, produces an intermediate composition of the same. The difference in magma composition can also be attributed to the fact that a particular rock is melted in different temperatures at different depths, but this is a relatively rare phenomena.
Effusive volcano
Explosive volcano