what is igneous rocks
Answers
Answer:
Igneous rocks form when hot, molten rock crystallizes and solidifies.
Explanation:
Answer:
Igneous rocks (from the Greek 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.
Examples of intrusive igneous rocks are diorite, gabbro, granite, pegmatite, and peridotite. Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals.
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.
Igneous rocks can be easily identified with their texture, density, color, and mineral composition. Its texture depends on upon the shape, size, time period to cool down and solidify and the arrangement of crystals in the rock.
Igneous rocks are also known as magmatic rocks. Igneous rocks are divided into two types: plutonic and volcanic rock.
Where Igneous Rocks Are Found. The deep seafloor (the oceanic crust) is made almost entirely of basaltic rocks, with peridotite underneath in the mantle. Basalts are also erupted above the Earth's great subduction zones, either in volcanic island arcs or along the edges of continents.