Ring dike

[2] The most commonly accepted method of ring dike formation is directly related to collapse calderas.

As pressure in the magma chamber changes, an increase in tensile stresses create tension fractures at the surface of the volcano.

[7] These dikes can form as a direct result of collapse caldera formation, or through many injections around the ring fault over time.

[10] Whether or not a caldera ring fault dips inward or outward from the center of subsidence is a highly contentious issue.

The composition varies from rhyolite to felsite, with phenocrysts of alkali feldspar and mafic minerals.