Sedona Westerners in the Red Rock News

January 23, 2015

Jerome Back in the Day

 


by Lynn and Ernie Pratt

A Sedona Westerners tracker hike is usually a good walk with a chance to learn and discuss special interest topics with an expert leader. This one focused on the geology of the Jerome ore deposits. The trip was lead by Paul Lindberg, a geological engineer who has had both a professional and personal interest in the Jerome ore deposits and Verde Valley geology since moving to Sedona in the early 1970’s. Paul was fortunate to be involved in the subsurface drilling program that positioned wells in the Jerome area. The results of this program greatly added to the understanding of the Jerome ore deposits and the structure and formation of the Verde Basin.


The first stop was at the top of the former open pit mining operation in Jerome. Paul detailed the formation of the main copper ore deposit, covered a bit of the town’s history and as a bonus, briefly explained the geology of the Verde Valley using posters and rock samples.

The second stop involved hiking up the ridge behind Jerome to access an outcrop positioned on Cleopatra hill high above the J. The hike was a distance of just over two miles achieving 500 feet of elevation. Paul commented that the ascent “would not be without its faults,” and at least four of them were crossed during our educational journey. We parked on some of the oldest rocks exposed in the Jerome area - Precambrian submarine turbidites and then walked upwards on a road cut. The walk took the group through geological time, stepping over the Great unconformity and the missing 1 billion years of section and onto the Tapeats Sandstone. The climb continued up to the ridge forming Martin dolomites. Geologically speaking, lunch was on a fossiliferous bioherm high above Jerome.

While eating we could see the snow capped San Francisco Peaks. Sedona was resplendent beneath the prominent Mogollon Rim which stretched across the horizon, and the group could look down into the Verde Valley and Jerome far below. After a somewhat “rocky” descent back through time, the hikers moved on to the next stop at Douglas Mansion State Park.

This museum exhibits historical photographs and artifacts from Jerome. There is also a wonderful mineral display as collected by Rawhide James Douglas; the man behind the bonanza discovery called the Little Daisy mine. There is much to see and study in this museum but on this day the focus of the trackers was the 3-D models of the underground tunnels and subsurface geology. Paul Lindberg built the most impressive of these models in his garage, incorporating 60 years of geological data to give a clear visual picture of what the earth looks like below the surface of Jerome. The various types of mineral specimens that make up the Jerome ore body frame the model. In a separate room is a large 3D engineering model of the mined areas in and around the town. All the shafts and tunnels that had been built by the 1930’s are shown in this model along with the main fault as mapped at that time. The purpose of this model was to prove in court that the mine development had not caused the landslide in downtown Jerome that wiped out a part of the town core.

The final stop of the day was a return to the open pit where Paul was able to bring the whole journey together. Using another handmade geological model, he further explained the geology and faulting which created the ore bodies and the surrounding hillsides. It brought the trackers a better understanding of the models in the museum and tied in the geology we experienced on our hike. A very good day!

If you are interested in joining the club, please go to our website at http://sedonawesterners.org or just come to one of our monthly meetings. The next one will be on Thursday, February 12, 2015 at 7 pm at the Sedona Elks Club, 110 Airport Road.