Some more boulder action on the southwest side of Cone Mountain. To see more from this hike: [ youtube video ]

https://pubs.geoscienceworld.org/gsa/bo ... m=fulltext The McDowell Mountains of central Arizona contain one of the best preserved and thickest sections of pre–Apache Group Mesoproterozoic rocks in the state. The oldest formation, ash-flow tuff, has an age of ca. 1650 Ma and is overlain by a quartzite-shale-quartzite triplet. hese two units are interpreted to correlate with the Red Rock Group and Mazatzal Group,