The melt originates deep within the Earth near active plate boundaries or hot spots, then rises toward the surface. Igneous rocks are divided into two groups, intrusive or extrusive, depending upon where the molten rock solidifies. Intrusive, or plutonic, igneous rock forms when magma is trapped deep inside the Earth.
What are intrusive igneous rocks?
Intrusive rocks are formed from magma that cools and solidifies within the crust of the planet. When lava comes out of a volcano and solidifies into extrusive igneous rock, also called volcanic, the rock cools very quickly.
What is the difference between andesite and anorthosite and basalt?
1 Andesite is an extrusive igneous rock that is higher in silica than basalt and lower than rhyolite or felsite. 2 Anorthosite is an uncommon intrusive igneous rock consisting almost entirely of plagioclase feldspar. 3 Basalt is an extrusive or intrusive rock that makes up most of the world’s oceanic crust.
What is the difference between igneous rocks and magma?
Igneous rocks. Magma is molten rock (liquid or liquid/crystal “mush”) that exists below earth’s surface (when cooled it forms rocks such as granite, diorite or gabbro). Extrusive igneous rocks are erupted in a molten state on the earth’s surface and then cool and solidify. Volcanic processes associated with this are natural hazards or disasters.
What does the size of mineral crystals in an igneous rock indicate?
The size of mineral crystals in an igneous rock may indicate the rate at which the lava or magma cooled to form a rock. Crystal size can also be affected by the number of gases or the availability of the chemicals in the molten rock that are required to form the crystals. Larger crystals generally indicate intrusive igneous rocks.
What is the difference between basalt and pumice?
As basalt is rich in iron so it is used as an ingredient of concrete. Basalt is the most common type of igneous rock. Pumice is a light igneous rock with thousands of tiny bubbles in them. They are used to remove dead skin from the bottom of their feet. It is used in abrasive cleaning products.
