So, after we visited the sewer river on Saturday, we headed up the gradient a bit and stopped at another bridge. The landscape looked surprisingly familiar, and before I even got off the bus, I had to verify that the surrounding rock was indeed tufa. What I didn´t know was that tufa is already an hispanization, and that real geologists call it ´tuff.´
Tufa is way harder than I had previously thought, being comprised of volcanic ashfall bascially compressed to a brick. It is surprisingly resistant to erosion, despite its sandy appearance, and it took quite a while for the river 300 m below to establish itself. There were a few flowering plants, some shrubs, the ever-present eucalyptus, and huge agaves just hanging off the cliffside. You know the soil´s not ideal when native plants still grow there . . .
The bus continued its climb up Papallacta into un ambiente increasingly colder, mistier, greener, and full of domesticated llamas grazing on 50-degree slopes. We stopped along the highway and crawled down into what I can only describe as the prehistoric birthplace of hobbits, otherwise known as the elfin forest (that is, if the speaker alludes to the gnome-like keebler elf and not the proper Tolkienesque counterparts . . .)