This process can occur either below the Earth’s surface, forming intrusive or plutonic igneous rocks like granite, or at the ...

Some other examples of igneous intrusions in Scotland can be found at Dumbarton Rock (a volcanic plug in Dumbarton) and Loudoun Hill (a volcanic plug in Ayrshire). Learn more about some of the ...

Snowflake obsidian is a form of volcanic glass that features white ... geological forces that create the material. Like other igneous rocks, the glossy glass originates from molten rock that ...

With our ideas of volcanoes we always associate the grand and the terrible ; and a volcanic eruption—a huge piece of artillery, with a mouth perhaps miles in circumference, shooting up rocks and ...