Ancient Landslides, Floods and Faults Lecture and Walk
Thursday, May 7 and Saturday, May 9: Geologist Aron Taylor, took us back in time last week to explore ancient landslides, floods and faults of San Juan Creek, with a lecture on Thursday followed by a walk on Saturday. Participants viewed and learned about the old floodplain terraces lining the edges of the creek and a slope wetland full of vegetation perched on the Cristianitos fault, an inactive fault that cuts through San Juan Creek. We also learned about a large ancient landslide that deposited angular blue-green schist along the creekside trail. We washed and hammered rocks to expose glimmering minerals that formed in subduction zones of tremendous heat and pressure. It was great to view the aerial photos in the lecture and then follow it up with a walk along the area of such a rich geological history.