“…He argued that the El Pichao Shear Zone represents a later thrust, explaining emplacement of hot rocks over the cooler rocks of the footwall. While this is possible, Finch et al (2015b) suggested instead that the two phases were part of a continuous top-towest shortening event, explaining the fact that both phases have the same transport direction and the hot-over-cold geometry. Finch et al (2017) dated monazite grains from within the El Pichao Shear Zone and from the footwall, and found an age difference of ~25 Ma (~460 and 435 Ma, respectively).…”