 The vias caldera is famous, famous, famous to volcanologists and geologists alike, because this is the place where the universal model of caldera formation and development was first devised by Bob Smith and Roy Bailey of the U.S. Geological Survey back in the 1960s. I found I could designate the vias as a type structure with a dome following subsidence with a structural dome. A type structure is the base model used to describe a concept. The vias caldera is used as that defining structure for all volcanic calderas in the world. The recertent dome, like redondo peak, is a structural dome. When the caldera forms, it blows a big hole in the ground because you're evacuating 95 cubic miles of pyroclastic flows. What happens first is that the floor of the caldera collapses and it fills in with some of the pyroclastic material. The magma body is still rising. It's less dense than the surrounding cold country rock. And as it rises, it pushes the floor of the caldera up into the sky. And redondo peak is a result of that uplift of continued magma pressure from beneath. So when you look at the rocks, the geology of redondo peak, what you're looking at is uplifted, banded or tough, that at one time was in filling the hole. But the magma body has pushed it up into the sky and you see that it's broken into a multitude of faulted blocks. One of the beautiful things about vias is that all the features are so perfectly exposed. You have this symmetrical circular caldera. You have the centralized recertent dome with a dramatic uplift. You have almost a perfect ring of rhyolite domes that have erupted along the ring fracture zone. And so you can put all this together and create this model. Other calderas, it's not as well expressed. And so it took the work of these two guys at this place to develop the model that became so universally accepted and used to this day.