The image below shows the Andean Volcanic Belt along the western side of South America. Answer the following questions:
a) What kind of plate boundary is denoted by the blue lines (highlighted by the red arrows) in terms of ocean/continent and convergence/divergence?
b) Given this type of boundary, why do these volcanoes exist?
c) Many volcanoes in this region are characterized by mafic volcanism. Provide two defining characteristics of mafic volcanic eruption behaviour.
d) Note that the areas of volcanic activity are separated by gaps of no active volcanism. What is the reason for these gaps?