What is igneous rock in geology?
Igneous rocks (from the Latin word for fire) form when hot, molten rock crystallizes and solidifies. The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface.
What are the 4 main types of igneous rocks?
As has already been described, igneous rocks are classified into four categories, based on either their chemistry or their mineral composition: felsic, intermediate, mafic, and ultramafic.
What are the 7 igneous rocks?
These rocks include: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff. Pictures and brief descriptions of some common igneous rock types are shown on this page.
How do you classify igneous rocks?
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 ( …
What are the three types of igneous rocks?
The most common types of igneous rocks are: andesite. basalt. dacite.
How is igneous rock formed step by step?
Igneous rocks form when magma (molten rock) cools and crystallizes, either at volcanoes on the surface of the Earth or while the melted rock is still inside the crust. All magma develops underground, in the lower crust or upper mantle, because of the intense heat there.
What are the three main groups of igneous rocks?
Igneous rocks are one of three main types of rocks (along with sedimentary and metamorphic), and they include both intrusive and extrusive rocks.
What is felsic igneous rock?
From Wikipedia, the free encyclopedia. In geology, felsic is an adjective describing igneous rocks that are relatively rich in elements that form feldspar and quartz. It is contrasted with mafic rocks, which are relatively richer in magnesium and iron.
How many kinds of igneous rocks are there?
The two main categories of igneous rocks are extrusive and intrusive.
How are igneous rocks formed 7?
Igneous Rocks They are formed by the cooling of molten magma on the Earth’s surface. The magma, which is brought to the surface through fissures or volcanic eruptions, solidifies at a faster rate.