A dark, fine-grained igneous rock that forms most of the Earth's crust.
A dark, fine-grained igneous rock that forms most of the Earth's crust. It has also been found on the Moon, Mars and Venus. Basalt is formed when lava cools and solidifies, either from volcanic eruptions or magma welling up between continental plates.
It has also been found on the Moon, Mars and Venus. Basalt is formed when lava cools and solidifies, either from volcanic eruptions or magma welling up between continental plates.