There are two main types of volcanoes: shield volcanoes and composite/strato volcanoes. Shield volcanoes erupt basaltic lava at constructive plate margins and have gentle, frequent eruptions that emit thin, runny lava. Composite/strato volcanoes erupt acidic lava at destructive plate margins and have potentially explosive, irregular eruptions that emit ash, rock fragments, and thicker lava.

1. Two main types of volcano
SHIELD Volcano COMPOSITE/STRATO Volcano
Plate margin
Constructive plate margin Destructive plate margin
Magma
Basaltic lava of low viscosity Acidic
Lava
characteristics Thin runny lava, low silica Vicious, high silica
Violence of
eruption Gentle – gases escape easily Potentially explosive, lava shatters
Materials
erupted Mainly lava Hot steam, ash, rock, lava bomb and dust
Frequency of
eruption Regular and frequent eruption Irregular (occasional) and violent
eruption, long dormant period
Example