Eruptions are affected by the local conditions, resulting in high altitude eruption columns that are sorted by westerly stratospheric winds. Coarse deposits are deposited close to the vents, while fine ash is carried to the Chaco and eastern cordillera. The highest volcanoes in the world are located here, including high Ojos del Salado and high Llullaillaco. Some volcanoes have undergone flank collapses covering as much as . Most calderas are associated with fault systems that may play a role in caldera formation.