A conical mound of volcanic ejecta accumulated around an eruptive vent. Cones have outer slope angles of about 30° and are topped by a depression or crater over the site of the vent. The type of material which accumulates to form the cone can be used to name the type of cone. For example, alternate layers of lava with beds of ash and other pyroclastic material characterize a stratovolcano (composite volcano), and spatter ejected from a vent during a Hawaiian-type eruption would accumulate to form a spatter cone around the vent. Scoria ejected from a vent during a Strombolian-type eruption would accumulate to form a scoria cone around the vent. See volcano.