A dike swarm (American spelling) or dyke swarm (British spelling) is a large geological structure consisting of a major group of parallel, linear, or radially oriented magmatic dikes intruded within continental crust or in rift zones. Examples exist in Iceland and near other large volcanoes, (stratovolcanoes, calderas, shield volcanoes and other ) around the world. They consist of several to hundreds of dikes emplaced more or less contemporaneously during a single intrusive event, are magmatic and stratigraphic, and may form a large igneous province.