«mush or thick ointment" (in Greek), it is a red-hot liquid molten silicate rock nature.That's what the magma.It occurs in the earth's crust in the upper mantle, at great depths.And with its cooling forms characteristic rocks.
What is magma?The definition in the dictionary
in different sources, the word "magma" is interpreted as a mass of molten rock, which is under a solid ground.It also indicates the composition of the silicate, and the ability to form igneous rocks.
Origin
fact that inside the red hot globe.The heat melts the rocks of the earth, which as a result are in a liquid state.What is magma?This liquid stone enclosed in a hard shell around him.It is much easier, by weight of the shell.Therefore, it rises up under the pressure arising.Sometimes magma erupts outward, gradually cooling down somewhere deep under the earth and hardens.So for thousands of years formed the mountains.Sometimes hard and colder rock can not withstand the high pressure of the magma inside.There are fissures through which magma escapes, poured out.She is still in a liquid state, it spreads along the ground.
What happens then
What is magma, which appeared on the surface of the earth?It is called lava.Once the magma erupted outside, she immediately begins to cool, interacting with the environment and the surrounding atmosphere.This happens fairly quickly.Some substances that are included in its composition, harden faster than others, forming crystals.The crystals are suspended in the liquid rock.And the biggest of them form the mountains of lava.All these mountains are composed of numerous crystals embedded in basalt.They are called porphyry.
chemical composition
What magma from the standpoint of science of chemistry?This rock contains many liquid chemical elements.Among them, magnesium, sodium, iron and potassium.Also - volatile components: chloro, fluoro, hydrogen, and others.And this component as vaporous water.As surfacing volatile elements (their number) are reduced, the process of decontamination.
Classification
- Basalt (main).It is containing silica (50%) and large amounts of magnesium, iron, aluminum, calcium.The smaller volume - titanium, phosphorus, potassium and sodium.
- Granite (sour, rhyolite).Containing silica (65%).It is more full of gas, is less dense than basalt.
- By the nature of the promotion and solidification process for several types of magmatism.Intrusive type - magma solidifies, crystallized deep within, without leaving the surface.Effusive type - magma erupts onto the surface and freezes already there.
solidification process
Molten magma consists of liquids, gases and solid crystals, which are in some kind of equilibrium.Under the influence of the environment the volume of magma tend to evolve.Some mineral crystals are melted, the other - arise again.
What is magma?This is a fairly complex solution in which the loss of solid crystals subject to physical and chemical laws.But even in the same composition of the magma changes sometimes under the influence of temperature and pressure.
pouring magma flow rate is sometimes as high as 30 km / h, temperatures - up to 1250 degrees.In liquid form, the magma is stored to a temperature of about 600 degrees, and then begins to solidify.
Thus minerals crystallize and are concentrated in certain areas of promotion, creating endogenous deposits of iron, non-ferrous and precious metals, diamonds.These igneous rocks occur in layered rock complexes.
What is magma and lava?
As already mentioned, the lava - it izvergnuvshayasya magma, consisting of viscous molten rock, mainly of silicate.The main difference from the first second - in the lava no gases that evaporate at the exit of "liquid stone".Lava has a tendency over time to cool and solidify, stopping their advance.As a result, formed lava rock mountains and even plateau.Different volcanic lava vary in composition, temperature and other characteristics.For example, carbonate lava brittle, soft, easily dissolve in water.
Volcanoes
We just think that the Earth is inside is solid and immobile.In fact, deep down permanently there is a movement of the molten substance - magma.She's looking for a way to the surface through various cracks and canals that occur in the Earth's crust.So there are volcanoes - which found the output magma erupts outward, sweeping away everything in its path.From the most famous eruptions (recorded by science), you can mark the release of magma on the island of Krakatoa in 1883.As a result, the island has been completely destroyed.The eruption claimed over 200,000 lives!
