Basalt Magma Lava
- The most common method of producing basaltic magma is depressurizing mantle rocks. Mantle rocks are extremely hot; they don't melt because they are held under high pressure in the earth.
- As these rocks rise to the surface, the pressure decreases and allows the rocks to begin to melt. This process is responsible for volcanism at mid-ocean ridges, Earth's most volcanically active features.
- Basalt lava is high in iron, magnesium, and calcium but low in potassium and sodium. It ranges in temperature from approximately 1000°C to 1200°C.
- Basalt lava can flow tens of kilometers from the erupting vent. Basalt lavas are relatively thin and are very fluid when erupted.
- On the continents, the mantle begins at depths of 30 to 50 km.
What is Basaltic magma?
Basalt magma is commonly produced by melting the earth's mantle directly, an area of Earth under the outer crust. For example, Hawaiian volcanoes. Basalt lavas are abundant because they are a product of mantle melting, which makes up most of the Earth's volume.