New Mining Threat in Jerome AZ

Author Note: This post was written in 2014.  That ‘threat’ seems to have evaporated. If anyone knows differently, please write to me.

The potential for mining to return to Jerome flew on the e-Mail hotlines because of newly announced information from Cornerstone Metals, a company located in Vancouver BC, to explore for a new cache of high-grade copper ore on property within a few miles of Jerome, Arizona.  “The West Jerome” prospect was one of four purchased by Cornerstone Metals, a British Columbia company in August 2013, from Copper One, Inc., which is based in Montreal, Canada.

Their website plays on the massive, and now fabled, tons of copper, gold and silver mined out of the old United Verde Copper Company, purchased by Phelps Dodge in 1935, and sold in 2006 to Freeport-McMoRan Copper and Gold, Inc., the largest publicly traded copper producer in the world and one of the world’s largest producers of gold.

According to the Cornerstone Metals website, “West Jerome was optioned to Lowell Copper Ltd. in February 2015 to advance the project to drill stage. Lowell Copper conducted 2 gravity surveys by Zonge International Inc. (“Zonge”) over the Project, which generated two anomalies, one being open-ended. Zonge recommended further work to better define the open-ended anomaly, however due to market conditions and other priorities, Lowell Copper has preferred not to proceed further with the Project. As a result, Cornerstone retains a 100% interest in the Project, now supported by gravity anomalies.”

What follows is some historical background and a few perspectives to think on when considering the question of whether a new ore body exists and if it does, how and when it might be mined.

Massive Sulfide Ores

The ore deposits mined in the Jerome area are described as massive sulfides.

As used by geologists, the term ‘massive’ refers to an ore body whose concentrations of all minerals exceed fifty per cent. The major  deposits that have been mined in and close to Jerome include the United Verde Copper Company (UV), the United Verde Extension (UVX) and the Verde Central Mine (about a mile outside of town going up towards Mingus Mountain).

The UV was the largest mined massive sulfide deposit in the United States. The copper ore was doubly famous for  its unusually high concentrations of copper. The UVX averaged twelve to thirteen per cent copper to the ton, with some concentrations as high as forty-five per cent, making it one of the two highest-grade copper deposits found in the world. The UV averaged five per cent copper to the ton. The majority of copper mines worldwide average less than one per cent copper to the ton (called porphyry copper). Low grade mines include the former Phelps Dodge copper mine in Bisbee, AZ and the still operating mine in Morenci, Arizona, both properties now owned by Freeport-McMoRan Copper and Gold, Inc.

Billions of dollars of copper, gold silver and zinc were mined before the last of the Jerome area mines closed in 1953, when the price of copper plummeted after World War II.

The term ‘massive’ could equally apply to the size of the ore bodies. At the Jerome State Historic Park (old Douglas Mansion), a three-dimensional display that takes up a large room, shows a city underneath Jerome that is larger than the one that used to be above it: eight-eight miles of mining tunnels going deep under the surface. The UV ore body, which resembles a deformed spheroid, extends some 4500 feet below the surface. According to one geologist, it weighed 150 to 200 million tons.[1] The more obloid-shaped UVX ore body extends to a depth of 2400 feet below the surface and is perhaps almost as wide as it is deep.

The display was built in 1938 to help settle legal disputes about the cause of the 1937 landslide that wiped out three city blocks in Jerome and shows the location of the areas of the ore bodies that were being mined underneath Jerome, as well as the areas that have already been mined.

The display shows that as much as 50% of the remaining ore has yet to be mined. Geologists also tell me there is ore remaining in the Verde Central Mine. Geologists tell me there is a rich lode of low-grade zinc at the upper part of the open pit; and that a lode of copper exists not far underneath Jerome’s Main Street (the Hermit Claim).

Where is the West Jerome property?

Mapshown on Copper Oner's web site before sale of the West Jerome and other properties to Cornerstone Metals, Inc. in August 2013.

Map shown on Copper Oner’s web site before sale of the West Jerome and other properties to Cornerstone Metals, Inc. in August 2013.

Map shown on Cornerstone Metal Inc.'s web site.

Map shown on Cornerstone Metal Inc.’s website.

Map on Cornerstone Metal Inc.,s web site. Purple may indicate the lower Cleopatra rhyolite, some of it buried by other sediments.

Map on Cornerstone Metal Inc.’s website.

According to the maps that are shown above, the first shows a map published on Copper One’s website before the August 2013 sale: “The West Jerome property consists of approximately five square kilometers of claims on the west side of Freeport McMoran patented lands”

The other two maps are provided on Cornerstone Metals website identify the site as lying “2.4 kilometers south of the past producing United Verde Mine.” One target area shown on the Cornerstone website is a boundary area between two types of the Cleopatra formation, the lower and upper Rhyolite. The UV, UVX Hull and Verde Central ore bodies were located in the lower Cleopatra Rhyolite.

Both maps show the long vertical boundary to be on the left side of highway 89A as you go up towards Mingus Mountain at an elevation of about 6400 feet, with the exception of a corner that crosses the highway. The lower side of the boundary shown on the Cornerstone map is somewhat opposite the Woodchute campground (right side of the road) its upper edge south of the old UV at about the same elevation. (A more accurate location can be had by driving the curves (which I can’t do because I’m in Oregon right now). The land on which the prospect is filed is likely owned by the US Forest Service, but this needs to be checked out. I do not know.)

How Jerome’s Massive Sulfide Ores Were Formed

Geologists working in the Jerome area in the nineteen seventies proposed a new theory about the formation of Jerome’s ore bodies, among them Paul Lindberg, a distinguished geologist, who still resides in the Verde Valley.

According to the new theory, the massive sulfide ore bodies were volcanic in origin and were formed underneath the ocean 1.738 billion years ago, virtually at the same time as the formation of a large undersea volcano, the remnants of which are called the Cleopatra formation in Jerome. This Precambrian formation, varnished a deep burnt copper sienna, is an integral part of the town of Jerome and surrounding areas.

After this undersea volcano erupted, its large crater collapsed and developed fissures through which cold flowed. As they widened and deepened, the water heated up from the hot magmas (lavas) underneath. Sulfur and minerals dissolved in the super-heated water and began to concentrate and be carried upwards through hot spring vents. Massive sulfide ore deposits spewed out and were dumped out onto the ocean floor. This was happening on a gigantic scale, beneath the pressure of 3000 feet of seawater.

Robert Chaplin (“Chappy)”, an exploration geologist working for Newmont Mining[2] during that period estimated the size of the ancient pile of sulfides that was to become the UV ore body as being approximately “two miles long, up to 1,500 feet wide and 500 feet deep.” I wish I could ask Chappy how he estimated the size.

The phrase that accurately describes these types of ore bodies is “volcanogenic massive sulfides” (VMS).

Black Smokers

What occurred in the Jerome area so long ago is still happening today in other undersea environments, which helped prove the new theories about how Jerome’s ore bodies formed.

In 1977, scientists descended into the ocean in deep-sea submarines to explore volcanoes and hydrothermal hot spring vents associated with sea-floor spreading at their plate boundaries that were located near the Galapagos Islands.[3] There they made two astonishing discoveries, the second of which was relevant to the formation of Jerome’s ore bodies.

First, scientists discovered large chimney-like columns, some as high as a mile, growing out of the hot spring vents. Inside them, in temperatures exceeding 600 degrees Fahrenheit, they found an array of eerie life forms, species without eyes, eight to ten foot tube worms, snails the size of tennis balls, weird shrimps and crabs, sea creatures that had no relationship to life as many people had been taught to regard it. Photographs of an array of these fascinating creatures are posted on:

Second, scientists discovered large quantities of sulfide metal-laden fluids spilling out of the columns onto the sea floor. They termed the columns ‘black smokers’ because of the color of the smoke that resulted when the hot fluids met the icy water. They gave the term white smokers to columns that release cooler water (250-300 degrees F) and emit lighter-hued minerals, such as calcium. Paul Lindberg likened them to gigantic pressure cookers.

“Oceans of Ore: How an Undersea Calder Eruption Created Jerome, Arizona,” written by Dana Hunter is a more in depth article on the black smokers.

At the Galapagos Islands, samples taken from the metal fluids inside black smokers, ones that had solidified on the volcanic floor as well as samples of the chimneys themselves were virtually identical to those found by geologists in Jerome. Samples of black and white smokers and other minerals that were found by Paul Lindberg in the Jerome area are displayed in the Jerome State Historic Park (the old Douglas mansion). Two fascinating videos posted on youtube show the black smokers (1) Ore Factories of the Deep, and (2) Hydrothermal Vents:

Because of the enormous quantities of copper-, zinc-, lead-, gold- and silver-sulfide minerals that are being produced in these undersea smokers, some scientists call them “industrial ore factories.”[4]

Today, various newspapers report potential undersea ventures to mine these deposits, perhaps with the use of robots. A 2011 report was titled, “Will Deep-sea Mining Yield an Underwater Gold Rush.”[5]

How Jerome’s Ore Bodies were Discovered

A tip of the UV ore body was exposed at the surface of the Cleopatra formation (near the top of today’s open pit) when violent earthquakes shook the area surrounding Jerome some five to eight million years ago. The exposed ore oxidized into vibrant blue and red colors, signaling the presence of riches underneath.

As early as the 1500’s, and perhaps for hundreds of years earlier, Hopis from Northern Arizona began mining the ore body for azurite and malachite, minerals associated with copper deposits, and used them as pigments for their pictographs and for body paint.

In the sixteenth century, a group of Hopis led two Spanish expeditions to the Jerome mine from the Hopi village of Awatovi in Northern Arizona to Jerome, a distance of about 200 miles.

In 1583, Antonio de Espejo came with a small expedition to look for gold.  He was likely the first European to see the Verde Valley and he named the Verde River, “El Rio de Los Reyes” (River of Kings).  Diego Luxan, the expedition’s chronicler reported “the mines were so worthless that we did not find in any of them a trace of silver [or gold} as they were copper mines, and poor.” Espejo’s official report stated, “I found the mines and took from them with my own hands ores, which, according to experts on the matter, are very rich and contain a great deal of silver.” They turned back almost immediately.[5]

In 1599, Marcos Farfan de los Godos came to Jerome and reported a shaft about sixteen and a half feet deep and a nearby mining dump. He also reported his encounters with small bands of Yavapai Indians. According to him, the Yavapais used the blue rock they obtained from Jerome as coloring their blankets and for personal adornment.

The valley and the Jerome mines remained essentially untouched by the white man until 1871, when the Yavapai and some Apaches were driven into a large reservation centered near Cottonwood. It extended ten miles on either side of the Verde River from Camp Verde and 40 miles to its headwaters in Chino Valley.

In 1875, the reservation was summarily closed by federal order and 1476 Native Americans were herded out and force-marched to the San Carlos Reservation to the East of Phoenix some 180 miles. It was snowing when they started; many were barefoot. One hundred and fifteen people died and 15 babies were born, some stillborn. It was the Yavapai and Apache ‘trail of tears.’

In 1876, the first mines were staked in the Jerome area.

Does Another Massive Sulfide Ore Body Exist?

If it does, it would be big news.

As I look at geologic maps that show the area of the Cleopatra formation, it occurs to me that in this ancient remnant of a huge undersea volcano, there could have been a lot of undersea hot springs vents and more than just a few large sulfide deposits than those already mined.

With as much exploration and mapping as has occurred from the nineteen seventies onward by a number of geologists from a number of very large mining companies, it seems somewhat likely that some may have already been found, and held in deep pockets of mining companies, and other prospects, like “West Jerome” not quite fully explored.
In the late nineteen sixties, a group of geologists from a number of the largest mining companies in the world challenged old theories about how the ore bodies were formed inside the Cleopatra formation. Up to that time, geologists thought that there were channels outside of the Cleopatra through which rich metal-laden fluids flowed and replaced sections inside it.[6]

“This theory was developed by people who first to Jerome looking for ore and were involved inside the guts of the ore body,” said geologist Paul Lindberg, who was working for Anaconda at the time. “We needed to get out into the terrain.”[7]

Handverger was one of a group of geologists that systematically drilled holes from Potato Patch on Mingus Mountain down to find evidence either supporting or contravening the old theory. “Most Arizona copper deposits are surrounded by one to three miles of channels that lead to the ore bodies,” Handverger said. “We found no evidence.[8]

Lindburg did a lot of drilling south of Jerome, remapping all of the geology over to the Copper Chief mine above Cottonwood.

When geologists took samples of all the different sections of the Cleopatra formation, they found that it was divided into two volcanic formations, not one, as was previously thought. The bottom layer, now called the Lower Deception Rhyolite, contains intrusions of old basalt (lava) and other outcrops. The top layer, which they called Cleopatra tuff, contains virtually no rock intrusions. It is a self-contained host for the ore bodies. (Crystal tuffs are the remains of consolidated volcanic ash that contains minute crystals or crystal fragments.)

As an aside, C. Anderson, one of the geologists who helped with the reinterpretation of the genesis of the ore bodies, was part of the team that once proposed that the two formations were the same and that the ore bodies had formed through hydrothermal intrusions.[9] He was a scientist that was not uncomfortable at being proved wrong.

Lindburgh built a geologic model of the Verde Mining district that collates some of the information gleaned from exploration work from the nineteen seventies onward. The model shows the surface geology (all the different rock formations that surround the area and their depths) and and an interpretation of features and major events that affected the geology.

The model is at the Jerome State Park (Douglas Mansion). It shows just how complicated and messy the geology of the area surrounding Jerome is and why geologists consider to be one of the most unusual geologic phenomenons in the world.

Much more interesting than the big ditch,” as Geologist Paul Handverger of Verde Ex said about the Grand Canyon in a class that he gave at Yavapai College in the nineteen eighties.

The model summarizes most of the dynamic processes that have altered the area from 1.8 billion years ago to the present. You could earn a PhD in geology by studying just this small patch of real estate.

Jerome’s Messy Geology

Even superficial knowledge of how and when the Colorado Plateau formed its sedimentary layers, so clearly bedded in many parts of the Grand Canyon, will  help you understand that in the Jerome area, the ‘bedding’ is not alway so neat and straighforward.

Most of the formations can be seen on a drive out Perkinsville Road—the Tapeats sandstone, the Redwall limestone, Supai sandstone, the Martin dolomite (a type of limestone). However, if you stand near the post office where Perkinsville Road veers off the main highway, you can see that the Redwall limestones has dropped below the elevation of the open pit. Earthquakes occurred here about 10 million years ago, at a time when there was no Verde Valley and no San Francisco Peaks, causing the Redwall to downfault.

During that same period (ten to fifteen million years ago, the boundary area near what is now Jerome and Sedona began to stretch and bulge, thinning the earth’s crust and producing cracks or fissures. Lava poured out of them. New volcanoes were created, including Casner and House Mountain. (The volcanic field that encompasses the San Francisco Peaks did not start erupting until about eight million years ago.) This volcanic activity covered many area sediments with thick layers of basalt, called the Hickey formation. Today, you can still see their evidence all over the Verde Valley, covering some of the sediments around Cleopatra, Mingus Mountain and Woodchute and forming large pillars in Sycamore, Beaver and Oak Creek canyons.

If you walk to the edge of Verde Street, you can get a clear look at the Verde Fault, as it dips slightly south towards the Black Hills and causes a seam. When it crosses Gulch Creek, the precambrian Cleopatra formation  will be on one side of the seam and the other will be Redwall limestone, merely 350 million years ago. (The  Verde Fault follows the base of the rust-colored Cleopatra formation through the top of town just below the hospital and top of the Company Hill houses and then parallels Perkinsville Road for perhaps a mile before heading northwest.

If you climb Cleopatra (one way is up hospital wash) to the top, you’ll come to a place where the Cleopatra is sliced by another earthquake faultline, as though by some giant knife. The other side is Redwall limestone, high above where you see it at the end of Verde Street or by standing at the post office.

The earthquakes and volcanic activity that occurred has given area geologists a great puzzle as they try to figure out what lies under these formations and where a new massive sulfide ore body might be.

Aside from substantiating new theories about where the ore bodies originated and mapping the layers of area sediments, geologists were looking for evidence of undiscovered ones. (During the nineteen eighties, my son Mike traipsed up and down Mingus Mountain with Chappy, armed with John McNerney’s Jerome Gold Film mercury detector that was being manufactured in Jerome in the nineteen eighties, looking for new ore bodies. Mercury vapor is strongly associated with copper, gold and zinc deposits.)

Cornerstone Metal’s attempt at finding a new VMS deposit references the similar ‘stratigraphy’ and similar geologic features to the old UV.  The similar stratigraphy refers to the large Precambiran formations in and around Jerome, which are identified today as lower Cleopatra Rhyolite. The company says they identified electromagnetic anomalies that might indicate the presence of a new VMS deposit.

Upper Cleopatra formation and Walkway near Hull Canyon below Highway 89 A. Photo by Bob Swanson
Upper Cleopatra formation and Walkway near Hull Canyon below Highway 89 A. Photo by Bob Swanson, Near this area is the shaft that was dug by George Hull in the early part of the twentieth century.

However, at an 6400 foot elevation, the Cleopatra formation is nowhere in sight. It lies buried under other sediments, notably limestones and basalt (the lava capping Mingus and Woodchute Mountains and seen exposed in some areas near Jerome). The Cleopatra disappears from view after passing Walnut Springs on the way up to Mingus on Highway 89A. This means that drilling in the target areas show on the cornerstone maps will mean going down as much as a thousand feet or more to reach the buried Cleopatra and pull out samples of any potential massive sulfides.

Mining in Jerome after 1953

In 1954, small mining rights to dig ore from the open pit were leased by Phelps Dodge to three Verde Valley folks, who called it The Big Hole Mine. Between eight and twelve men, some from Jerome, scaled the sides of the pit and drilled into the pit or exploded out the ore-bearing rocks with dynamite, separated waste from ore-bearing rocks and took it down to Clarkdale in pickup trucks where it could be loaded up into a railroad car that was sent weekly to the Phelps Dodge smelter in Douglas, Arizona. Maybe 20-30 pickup loads a week went down the mountain at a time when work of any kind was very welcome. According to Paul Handverger, The Big Hole Mine shipped over 200,000 tons of ore containing 25 million pounds of copper (12,500 tons), 2,800 ounces of gold and almost 200,000 ounces of silver.[10]

In 1980, geologist Paul Handverger of Verde Ex discovered an unexploited source of microscopic gold in the old UVX mine. The gold, perhaps less than .02 ounces to the ton, was part of silica-rich quartz chert that could be used as flux in smelting operations. The gold would become a profitable byproduct.[11]

In 1985, Verde Ex leased mining rights to A. F. Budge Mining Limited (Budge), a company located in Scottsdale, AZ. Repair and exploration took about three years and in early 1988, Budge started production. Their goal was to take out 100,000 pounds of chert daily, using five to eight twenty-ton trucks going up and down the hill from Jerome to Clarkdale and to employ about forty people.[12] The mine was located just below the Arizona State Park (Douglas Mansion).

Like many issues that affect residents in a small village, strong arguments for and against the mine became increasingly negative and emotionally charged. Fortunately, the ruckus never quite exploded into a full-scale civil war because the mine never went anywhere. Although four different mining companies professed interest as buyers of the chert, contracts for the ore were not forthcoming. Budge shut down in 1989.

Will Discovery of a New Massive Sulfide Ore Deposit by Cornerstone Metals Lead to Mining It?

At that location, not too likely in any near future I can imagine. Here are some of my considerations:

  1. High concentrations of ore still exist in the three Jerome mines already mentioned. They are not being mined. Duff Sorells, who works in Jerome for Freeport-McMoRan, told me that, currently, the company prefers operating on foreign turf where the environmental laws are not as stringent as ours and where labor is far cheaper (the exceptions being the copper mines which were still operating when Freeport bought Phelps Dodge, such as the mine in Morenci.
  2. In the target areas shown on Cornerstone Metals maps, any new VMS deposit will mean underground mining at depths of many thousands of feet and building the infrastructure to sustain it.
  3. The environmental and mining permitting for opening or reopening mining in the United States is very stringent and can take fifteen years or more to accomplish.
  4. How the mine will protect water resources from contamination of waste products is a big issue, as is land reclamation. Phelps Dodge Corporation and Freeport-McMoRan Copper and Gold, Inc., its successor, spent multiple millions to clean up wastes and create new drainage pathways on the UV mine site that could potentially contaminate Verde Valley water resources. The problem was so severe that for years the EPA kept threatening to make the old UV property a Superfund site.  (The story of the “blue water streams ” in Jerome is the subject of a future blog).
  5. Mining uses a lot of water. Where would that water come from? And who has the rights for permitting it?
  6. How and where will ore be trucked out? Will it be taken to Clarkdale or over the mountain to Prescott. Will a road have to be built or rebuilt to not impact traffic on Highway 89A, perhaps over Mingus to Perkinsville Road and then down to Clarkdale?
  7. How does the ore get to a smelter?  Will a new one be built? Currently the nearest smelter is in Southern Arizona.

My final question to interviews conducted in the last few years with area geologists about whether mining would return to the area were answered like this:

Paul Lindberg” “I’ve been asking similar questions of mine managers ever since I began to understand the new geology of the area. If big mining did occur, the ore would be taken out through Hopewell [near what is now called the 500 level across and down from the big open pit] and people in Jerome wouldn’t know there was an operation.”

Paul Handverger: “As of the seventies, the second largest zinc reserves in the United States were identified up there near the open pit. It’s low grade, however, and Phelps Dodge was never interested in it. The Hermit ore body goes right down Main Street and a few hundred feet under is a lot of mineralized rock.”

What might be expected if a new massive sulfide ore body is found by Cornerstone Metals is for the company to sell the property to a large mining company that might, in the future, have the money and desire to exploit it and or other minerals that are already known to exist in the area.

So far, no dice.



[1]  Lindberg, Paul A., “Early Proterozoic Volcanogic Massive Sulfide Deposits,” Jerome, Arizona, USA Annual Geological Society Digest 22, 2008, page 605.

[2] Chappy, “Historical Notes: Geologically Speaking,” Jerome Times, April 29, 1983.

[3] The expedition included geologists, geochemists, and geophysicists from the Woods Hole Oceanographic Institute, Oregon State University, the Massachusetts Institute of Technology, Stanford University, and the U.S. Geological Survey who used cameras and a manned dive in the smaller submersible Alvin.

[4]  Miner, Meghan, “Will Deep-sea Mining Yield an Underwater Gold Rush,” National Geographic Daily News, 2/1/2013.

[5] Byrkit, James, W., “The Palatkwapi Trail,” Journal of the Museum of Northern Arizona, 1988, page 12.

[6] Lindberg, op. cit.  The selective placement theory.

[7] Author interview with Paul Lindberg 2012.

[8] Author interview with Paul Handverger 2012.

{9} Anderson, C.A., and Creasey, S.C., 1958, Geology and ore deposits of the Jerome area, Yavapai County, Arizona: U.S. Geological Professional Paper 308, 158 p.

[10 ] Email to author.

[11] Verde Independent, Nov 11, 1987 and author interview with Paul Handveger 2011.

[12] Author conversations with Budge mining foreman Pete Flores and geologist Don White.


5 thoughts on “New Mining Threat in Jerome AZ

    • Thanks, Erin. Love to read some of your stories about Jerome. Did you live there or just visit?


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