* Volcanic eruptions: The most common way basalt is formed is through volcanic eruptions. When magma (molten rock) rises to the surface and cools, it forms basalt. This can happen at:

* Mid-ocean ridges: These underwater mountain ranges are where new ocean crust is created. Basalt is the primary rock type here.

* Hotspots: These are areas where plumes of hot mantle material rise to the surface. The Hawaiian Islands are a prime example of a hotspot where basalt is formed.

* Continental volcanoes: Basalt can also be formed at volcanoes on continents, although it is less common than in other settings.

* Extrusion: Sometimes basalt is extruded from the Earth's surface without a violent eruption. This can happen in the form of:

* Lava flows: These are slow-moving rivers of molten rock that can travel for miles.

* Lava fountains: These are eruptions that send molten rock high into the air.

* Other: Basalt can also be formed in other, less common ways, such as:

* Meteorite impacts: The heat and pressure from a meteorite impact can melt rock and form basalt.

* Subduction zones: Basalt can be formed at subduction zones, where one tectonic plate slides beneath another.

No matter how it's formed, basalt is a very common rock type that makes up a significant portion of the Earth's crust.