<P> Basalt with a vesicular texture is called vesicular basalt , when the bulk of the rock is mostly solid ; when the vesicles are over half the volume of a specimen , it is called scoria . This texture forms when dissolved gases come out of solution and form bubbles as the magma decompresses as it reaches the surface , yet are trapped as the erupted lava hardens before the gases can escape . </P>
what is the origin of vesicles in a basalt
dissolved gases come out of solution and form bubbles as the magma decompresses as it reaches the surface , yet are trapped as the erupted lava hardens before the gases can escape