To continue the previous chapter which ended with plutons, vulcanogenic structures are the subject of this chapter. Such igneous rocks reach the surface through vents in the Earth’s crust like vulcanos. This chapter includes examples of geological maps of vulcanogenic structures and deposits and explains some of the basic features necessary for an elementary understanding of such maps. This starts with the exploitation purposes of vulcanic deposits in the first section. The ocean floor and moreover different vulcano types are then outlined in section 14-2 to 14-5. Mat patterns of mudflows and glowing avalanches are illustrated in the next two section. The chapter ends with craters, calderas and eroded vulcanic landforms in sections eight and nine.