Barrons AP Environmental Science

(A) Cinder cones are one of the most common types of volcanoes. A steep,
conical hill of volcanic fragments called cinders accumulates around a vent.
The rock fragments, or cinders, are glassy and contain numerous gas
bubbles “frozen” into place as magma explodes into the air and then cools
quickly. Cinder cones range in size from tens to hundreds of meters tall and
usually occur in groups.