This depends on the type of plate boundary. Spreading centers tend to make fissure flow-type volcanoes, while convergent plate boundaries more often make strata volcanoes and sometimes shield volcanoes. Both can make large calderas while on land, as in the case of Iceland (situated on top of the North Atlantic spreading center) or Tambora (on the convergent plate boundary in Indonesia). It is thought that the breaking of plates to create new spreading centers may be associated with flood basalts as well, as in the case of the triple-junction between Africa, Sudan, and Arabia.