The oceanic Nazca tectonic plate is subducting at a rate of beneath the continental part of the South American tectonic plate; this process is responsible for volcanic activity and the uplift of the Andes mountains and Altiplano plateau. The subduction is oblique, leading to strike-slip faulting. Volcanic activity does not occur along the entire length of the Andes; where subduction is shallow, there are gaps with little volcanic activity. Between these gaps lie volcanic belts: the Northern Volcanic Zone, the Central Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone.