What Type of Volcano Is Formed From Layers of Lava and Volcanic Ash?

A stratovolcano is formed from alternating sheets of lava flows and pyroclastic materials, such as volcanic ash, lapilli, volcanic bombs and cinders. This type of volcano is also referred to as a composite volcano. Examples include Mt. Fuji, Vesuvius and Mount St. Helens.

Volcanoes are natural land forms that are generally classified into three major types: stratovolcano, shield and cinder cone. Stratovolcanoes are characterized by their relatively symmetrical cones having sides that slope inward and grow steeper towards the crater.

The stratification of composite volcanoes is due to the andesitic type of lava flow that cools down into blocky layers. The rock fragments that alternate with the lava flows are collectively known as tephra. Among these pyroclastic ejecta, volcanic ash consists of the smallest particles.