For its size, the Verde Valley contains one of the richest troves of geologic history in all of Arizona (no small feat considering we are the Grand Canyon state)! Precambrian-age rocks preserve evidence of a submarine volcanic system that yielded a world-class mineral deposit, leading to the development of Jerome. These basement rocks were ultimately buried beneath a thick section of sedimentary rocks, including Sedona's world-famous Red Rocks. At a much later time, the House Mountain shield volcano erupted within the Verde Valley near present-day Cornville. This eruption slightly pre-dated the existence of a valley-wide, freshwater lake that preserved some amazing fossils. The finishing touch on this geologic masterpiece includes the carving of beautiful Oak Creek Canyon into the southern margin of the Mogollon Rim. Geologist and author Wayne  Ranney is no stranger to Prescott and the Verde Valley, having served as adjunct professor of geology at Yavapai College for 17 years. In the 1980s he completed a Master's Degree at Northern Arizona University, mapping the House Mountain volcano.  He is a sought-after lecturer on natural history expeditions for Smithsonian Journeys and National Geographic around the globe. Ranney  is also an award-winning author who writes for various magazines including Arizona Highways. He is perhaps best known however for his books, Sedona Through Time, Carving Grand Canyon,  Ancient Landscapes of the Colorado Plateau and Ancient Landscapes of Western North America.  Geology Talks are held in partnership with the Prescott Geology Club and are presented with funding from the Friends of the Prescott Public Library.