Scientists have made a major break-through in their understanding of the structure of the Earth. Careful observation and recording of data has enabled a leading team of scientists to describe how granite was formed and why different pieces of granite have different sized crystals in them. We interviewed one of the scientists who said …
Formation of igneous rocks magma intrusive igneous rock extrusive igneous rock Igneous rocks are formed when magma cools and solidifies. How are igneous rocks formed? Deep in the ground is molten rock called magma . Sometimes, magma bursts through the surface causing volcanic eruptions.
When magma cools above the surface, extrusive igneous rocks are formed.
When magma cools below the surface, intrusive igneous rocks are formed.