Dike swarms are emplaced along ring fractures and fault zones at the southwest edge of the caldera. Near the dying stages of the volcano, magma surged upward and arched the roof of the magma chamber into a broad dome with relief of about .
Dike swarms are located along ring fractures and fault lines at the southwestern edge of the caldera. Near the final stages of the volcano's activity, magma surged upward and created a large dome within the magma chamber with a height of about .