The magma is derived from the melting of the molten rocks below at greater depths in the mantle of the earth as these rocks are melted new lava or magma is formed from the ridges of the mid-oceanic plate and tends to rise in the form of hot basaltic lava and flows with gases and tick matter when its emitted from the surface of a volcano.
The thickness of lava tells us about its qualities and presence at greater depths in the earth.
