United Verde Mines, Jerome (Verde) district, Arizona

Black Smoker from the bottom of the ocean
in Arizona! Yes, when this hydrothermal vent
was active more than 1.7 billion years ago, 
Arizona sat at the bottom of an ancient ocean
where deep hot-springs emitted gas and sulfides
from such vents and produced one of the greatest
massive sulfide deposits ever found, and high
and dry, Jerome, Arizona.

From Flagstaff, we decided to take a detour to the Verde district: a highly mineralized area. The district is 90 miles north of Phoenix along the edge of the Black Hills in Yavapai County, central Arizona and locally referred to as the Jerome district. It encloses a 30 mi2 mineralized terrain with two major mines along the northern edge of the town of Jerome. The two principal mines in the district are the United Verde and United Verde Extension. To get to the district, drive south on Highway 89A from Flagstaff. You can also visit the town on your computer by searching for “Jerome, AZ” with Google Earth.

On the northwestern edge of Jerome is a large, partially reclaimed, open pit mine that is part of the United Verde mine. The rest of the mine lies underground and inclues 81 miles of tunnels and shafts hidden beneath the open pit, Cleopatra Hill and the adjacent valley. A large active quarry is visible near the northeastern edge of town that is actually the Clarkdale quarry and cement plant, which has little to do with the base metal mines. Evidence of the old smelter works is visible further east near the Verde River and expressed as black slag with some old buildings and foundations.

If you are familiar with gossans, you should be able to trace an extensive belt of rusty-colored rocks on aerial photographs on Google Earth. I followed the gossan 7 miles north of the United Verde Mine, and another 7 miles south! Such an extensive gossan likely hides ‘blind deposits’! My experience is that for every mineral deposit found on the surface, there likely is many more hidden at depth in the immediate area (and who knows how many lie hidden under the adjacent valley sediments). And like most mines reported to have been mined out, the United Verde is far from being mined out. In fact, the US Geological Survey reported at least twice as much unmined ore remains in place as was mined in the past. Actually, it is extremely rare for a major mineral deposit to be mined out as most productive mines terminate operations because of declining economics as prices and markets fall during bad times.

Jerome, Arizona, looking towards Cleopatra Hill. The hill with the ‘J’ is Cleopatra Hill and the 

United Verde open pit is the mine dump seen in distance to the right of the J between the two 

prominent hills. The tops of two head frames of the United Verde Extension mine are visible in the

foreground.

When I was a student in geology, the Verde district was considered as an exploration model for ‘submarine volcanogenic massive sulfide deposits’. One geological dictionary defines massive sulfide very simply as: “an unusually large deposit of sulfide minerals”. But there is more to massive sulfide deposits.

Massive sulfides bring thoughts of copper and zinc to geologists. And for myself, I also think of precious metals. Sulfide minerals in many of these can enclose significant amounts of gold and silver. So much silver was found associated with these deposits at Jerome that the recovered silver essentially paid for the mining operations. And many banded cherts (known as exhalites) associated with ‘submarine volcanogenic massive sulfides’ (VMS) contain anomalous gold.

VMS refers to a type of mineralization with zones of massive (as well as disseminated) sulfide minerals that were deposited beneath the ocean in hydrothermal vents including white and black smokers. Over geological time, many of these VMS deposits now lie on dry land due to tectonic forces while modern deposits continue to form under the ocean. Where found, VMS deposits are hosted in rocks 3.55 billion years old to the present and may even include deposits with a hundred million tons of ore rich in gold, silver, copper, zinc, lead and other metals.

White smoker sinter column. White smokers precipitate in hydrothermal vents and often 

have auriferous silica. Black smokers are sulfide rich and associated with higher 

geothermal temperatures (specimen from the United Verde mine, and on display at the 

Douglas Museum in Jerome).

VMS deposits have distinct rocks such as volcaniclastics (breccias) that represent very active submarine vents. Some of these are so distinct that one Canadian geologist dubbed them ‘mill rock’ years ago because he noticed there were operating mills and mines adjacent to many of these.

In addition to volcaniclastics (mill rock), siliceous mounds or chimneys are formed by submarine fumaroles that are referred to as black and white smokers. Other distinct rocks include layered stratiform rock known as exhalites that formed during eruption of heterogeneous volcanic material in sea water: the layering was produced by sea water naturally separating minerals by specific gravity as they slowly settled in the ocean water.

The host rocks for the VMS deposits in Jerome are 1.7 billion years old and similar in age to VMS deposits discovered in Colorado and Wyoming in 1979 and the early 1980s. You might be wondering what submarine VMS deposits are doing in the dry deserts of Arizona and high mountains of Colorado and Wyoming? In the geological past, these were accreted to continents and buried by tectonic forces related to continental drift. After millions of years of erosion following mountain uplift, some have been exposed at the surface, while many more remain hidden and undiscovered. Those hidden at depth are referred to as ‘blind’ deposits. Still others continue to form in the oceans, particularly along active volcanic island chains (such as Japan) and along spreading centers such as the Mid-Atlantic Ridge.

When I was the Senior Economic Geologist and Deputy Director at the Wyoming Geological Survey, Conoco Minerals discovered VMS deposits in 1979 in the Sierra Madre Mountains west of Saratoga. But few have heard of these deposits because of the US Forest Service. Those that were found near the old Itmay mine, not far from the famous Ferris-Haggarty mine, were withdrawn from public use. Other VMS deposits were soon found in Colorado and Wyoming. The discoveries sent shock waves through the Forest Service which had little taste for mining; and the agency hurried to withdraw the new discoveries until all, or portions or most VMS deposits fell within or adjacent to the withdrawals effectively locking out mining companies and prospectors from public land.

Much of this region in Colorado and Wyoming was known as the Grand Encampment district, which in the 19th century, prior to government interference, was a major base metal district. But because of the withdrawals, no jobs were created because of Conoco’s discoveries, no valuable metals were mined, and the US continued out-sourcing jobs and importing base metals.

Today, the Verde district is idle and the town of Jerome is a tourist attraction built on the flank of Cleopatra Hill which rises more than 6,000 feet above sea level. Some buildings in Jerome were constructed on the Precambrian rock that forms Cleopatra Hill, while the rest of the town slopes downward on Tertiary to Recent fanglomerates and landslide debris. The landslide has been a historical problem and periodically slides following periods of high runoff. At the base of the slope, the surface flattens eastward to the Verde River valley at Clarkdale and Cottonwood 4 to 5 miles east of Jerome at an elevation of 3,300 feet.

Production

Jerome was a major copper-gold-silver-zinc-lead district. According to the Arizona Department of Mines and Mineral Resources (2007), 48 of 70 known VMS deposits found in Arizona have produced ore - all of which are Precambrian age (1.7 to 1.8 billion years old). Production from these totaled more than 55 million tons. Most of these deposits are steeply plunging and deformed, such as the United Verde, which has been described as a rod-like ore body or pipe located within an axis of a major, steeply-plunging, fold.

About 98% of the past production in the Verde district was from the United Verde and United Verde Extension mines. Even though mining ceased in 1953, there is evidence that the miners left behind considerable ore. The district was considered to be a copper district, but at today’s metal prices, the district would be classified as a copper-gold-silver-zinc district. Considerable copper, gold, silver with some zinc and small amounts of lead were recovered from the two principal mines.

In 1989, the US Geological Survey indicated records from Phelps Dodge showed production from the United Verde Mine from 1884 to 1975 amounted to more than 2,926,900,000 pounds ($10.1 billion at 2012 prices) of copper, 97,891,000 pounds ($82 million) of zinc, 459,000 pounds ($390 thousand) of lead, 49,603,000 troy ounces ($1.4 billion) of silver, and 1,354,200 troy ounces of gold. Koschmann and Bergendahl of the US Geological Survey reported gold production was even higher at 1,571,000 ounces ($2.5 billion) over the lifetime of the district. Based on statistics from the U.S. Geological Survey and Phelps Dodge, the United Verde produced $14.8 billion in metals at 2012 prices.

High wall of the United Verde open pit mine with head frames in foreground. Note large distinct, rusty gossan produced by oxidation of massive sulfides in the background. The massive sulfides were so rich that they actually ignited and burned underground for many years!

History

The cupriferous gossan exposed at the surface at Jerome was found by prehistoric tribes hundreds of years ago. In 1875, the U.S. Army rediscovered the gossan and in the following year (1876) prospectors rushed to the district to claim the discovery. By 1882, much of the minable land had been consolidated by the newly formed United Verde Copper Company which began extracting near-surface oxidized and supergene enriched copper ore rich in gold and silver. Underground mining began in 1883, and open pit mining was initiated in 1920.

A second company, (United Verde Extension [UVX]), was organized in 1899 to search for a suggested, down-faulted continuation of the United Verde massive sulfide. UVX began searching southwest and east of the United Verde property. Their efforts were fruitless until they were on the verge of bankruptcy in 1914, when a drift driven from a shaft east of the United Verde mine intersected bonanza grade ore rich in chalcocite on the 1,200 level. In 1916, another ‘blind’ deposit was found. The ore was so rich the company ended the year with a 74% profit after expenses. Later geological studies showed the UVX discoveries were not part of an off-set of the United Verde ore body, but instead completely separate, ‘blind’ ore bodies.

The UVX mine operated on a large scale until 1938 when much of its high-grade was mined out and operations ceased. The nearby United Verde mine continued mining. After 1931, much of their activity focused on open-pit mining. Depletion of ‘high-grade’ reserves finally forced the mine to close in 1953. This resulted in many people reporting that the deposit was mined out. However, the operations left behind a giant, low-grade, ore deposit and who knows how many ‘blind’ deposits.

Geology

The VMS erupted as hot, sulfide-rich material into cool water resulting in precipitation on the ocean floor 1.7 billion years ago. The Verde VMS lies at the top of a submarine rhyolite dome and flow breccia known as the Cleopatra Member of the Deception Rhyolite. The ore is zoned and capped by chert and siliceous massive sulfide that grades down into pyrite-rich massive sulfide, zinc-rich massive sulfide, copper-zinc-rich massive sulfide, chloritic stringer ore, and chloritized quartz porphyry ore. Gold is found throughout but is in greater concentrations at the stratigraphic top (siliceous massive sulfide and chert ore).

Gold is in greater concentrations in chert. For instance, on the 4500-foot level, the black schist yielded 0.002 opt Au and 0.71 opt Ag. In chert near the surface, the ore yielded values as high as 0.12 opt Au and 4 opt Ag (60 times more gold). On the 700-foot level, the massive sulfide averaged 10 times more gold than the black schist. A positive correlation of gold with higher zinc content was also recognized by the US Geological Survey. This is important as much zinc ore was not mined.

Sulfides are exposed at the surface down to the 4500-foot mine level, but in the geological past, the ore also extended upwards to the base of the Cambrian Tapeats Sandstone indicating at least 350 feet of vertical column of massive sulfide was removed by erosion. With this much erosion, drainages down-slope from the massive sulfide should contain detrital gold, but I could not find any report suggesting that gold had been detected in the nearby drainages. Based on the mode of occurrence, the gold would likely be very fine grained.

Ore minerals in the massive sulfide in decreasing abundance included pyrite, sphalerite, chalcopyrite, bornite, arsenopyrite, galena, tennanite and gold (electrum). Much of the electrum is thought to be present as microscopic inclusions in sulfide minerals. Silver is present in the electrum and in late-stage tennanite (Cu12As4S13) in quartz carbonate veins and in carbonate rich massive sulfide ore. The tennanite also contains gold as microscopic inclusions.

The Verde was the largest known volcanogenic massive sulfide deposit in the US with 33 million tons of mined ore, and 50 to 70 million tons of low-grade ore left in place. It is also considered to be one of the largest in North America. The massive sulfide was steeply-dipping, irregular- to cylindrical-shaped ore body approximately 700 to 800 feet in diameter that extended 2,400 feet deep. The United Verde mine reached a depth of 3,515 feet and included eight shafts. According to the US Geological Survey, proximal ore recovered from the mine averaged 4.77% Cu, 0.046 opt Au, and 1.65 opt Ag. Zinc and lead were not recovered during much of the operations. Another blind ore body was found in the lower levels of the mine 500 feet northwest of the roots of the main deposit.

Anomalous gold was detected in the pyritic and sphalertic massive sulfides and the chert rich ore: chloritic host rocks are poor in gold. The zinc ore contained as much gold as the copper ore. And because only the high-grade copper-rich portion of the massive sulfide lens was mined, a very large tonnage of low-grade ore remains in place and it was estimated that at least 75% of the mineralized deposit remains unmined because it was too low-grade to mine (<2% Cu) under historical economics. The estimates suggest about 115,000,000 tons of low-grade massive sulfide ore and 38,000,000 tons of mineralized black schist remain in the mine with grades of 0.5 to 1% Cu, 2 to 4% Zn, 0.01 to 0.015 opt Au and 0.5 to 1.0 opt Ag. This zinc-rich deposit is estimated to have 400,000 troy ounces of gold.

At the United Verde Extension Mine, mineralization occurred in an elliptical ore body hosted by the Deception Rhyolite and Grapevine Gulch Formation. The main chalcocite ore body was found on the 1400-level and was 269 feet wide and 440 feet long on this level.

You may not appreciate this exhibit at the Audrey Head-frame Park in Jerome if you have.

a fear of heights. Sunlight is projected down the 1900-foot deep Audrey shaft so visitors can

see the depth of these mines. When I took this photo, I was standing on the plexiglass

covering the deep shaft.

The UVX mine produced 3,879,000 tons of ore that averaged 10.23% Cu, 0.039 opt Au, and 1.71 opt Ag. Ore minerals included chalcocite, cuprite, native copper, malachite, chrysocolla and azurite hosted by felsic fragmental rocks, massive rhyolite and quartz porphyry – all units of the Deception Rhyolite.

Part of the UVX operation was developed by the Haynes Shaft due west the United Verde open pit. This deposit was another blind ore body found at 2,500 feet below the surface. The UVX decided to explore the ground under the Haynes shaft by driving a tunnel at the 3,000 level. A drift was started in 1930 and reached the Haynes massive sulfide pipe in 1931.

The Haynes proximal pipe was a steeply-plunging massive sulfide. It extended a short distance above the 2700-level downward to an undetermined point between the 3450 and 3700 levels of the United Verde Mine. The Haynes haft was sunk to 700 feet between 1907 and 1911; subsequently deepened to 1,200 feet, with 1,700 feet of drifts and crosscuts on the 700 level and 700 feet on the 1200 level.

Gold Basin District, Arizona

Many dry gold placers are found along the eastern edge of the White Hills extending east to Hualapai Wash in Mohave County (T28 & 29N, R17 & 18W), NW Arizona. These are the Gold Basin placers. Search for "Gold Basin, AZ" on Google Earth, and hopefully, you will arrive in the middle of Gold Basin, a short distance east and south of the many dry gold placers known in this basin. 

The area lies south of Lake Mead, the Lake Mead Recreation area, and the Colorado River. The nearest communities are Meadview (36o00’00”N; 114o04’00”) and Dolan Springs (35o35’25”N; 114o16’25”W). Due to the large number of retirees and snowbirds in the region, each community is surrounded by suburbs.

The placers are dry placers in the desert, and these contain detrital gravels (1 to 5 feet thick) that mostly lie on hard, false, bedrock of consolidated gravel cemented by caliche - unfortunately, there is no shortage of caliche in Arizona. The overlying gold-bearing gravels are weakly mineralized with considerable black sand, quartz, and rock fragments of schist and gneiss eroded from the Precambrian terrain in the White Hills. 

Gold content of the placers is poor and may only be 0.03 to 0.04 ounce per cubic yard at best; while the underlying consolidated gravel remains mostly unexplored. Gold nuggets are rare. Some up to an ounce have been found with the largest only 4 to 5 ounces in weight. Much of the gold-bearing area is part of the White Mountains alluvial fan that extends from the eastern flank of the uplifted White Hills to Haulapai Wash to the east. The fan covers a surface area of 6 by 5 miles and you can drive to the area northward on the Pierce-Ferry highway (Road 25) through Dolan Springs. 

Lode gold was discovered in quartz veins in Precambrian rock in the 1870s. Placer gold from the veins was not found until the Great Depression. In 1932, W. E. Dunlop found gold in the dry gravel which attracted others. The amount of gold recovered by the prospectors was minor. Even experienced miners only made about $1 per day (1933 wages). And the total amount of reported gold recovered from the Gold Basin placers is only 415 ounces produced during the period of 1934-49. 

The gold-bearing gravels occur in arroyos and gulches at elevations of 3,300 to 2,900 feet. The gravels have medium-grained, angular schist and gneiss fragments with a minor amount of finely divided quartz. A small number of boulders are encountered that are generally less than 2 feet in diameter. The gold occurs as flour gold and less commonly as angular nuggets with some gold attached to black schist particles. The White Hills, which are made up of granitic, schistose, and volcanic rocks, contain many argentiferous and auriferous quartz veins that are the likely source for much of the Gold Basin gold (Wilson, 1981).

The gold placers have erratically distributed gold. In addition to dry placer mining, there is considerable prospecting with metal detectors. Some find gold, while others have found a bonus of meteorite fragments.

Moss Gold mine, San Francisco District, Oatman, Arizona

“With thy wisdom and with thine understanding 

thou hast gotten thee riches, and hast gotten

 gold and silver into thy treasures:” Ezekiel 28:4

Arizona is known for many, giant copper porphyry deposits. The state's endowment of base metals, sometimes results in other deposits being overlooked by mining company execs even though the state has dozens of very attractive gold, silver, and massive sulfide and replacement deposits. The copper porphyries occur in extensive volcanic fields, filled with volcanic and plutonic rocks associated with large envelopes of hydrothermal and metasomatic alteration and mineralization. Overall, such geological environments are favorable for porphyry copper, gold, silver, lead, zinc, molybdenum deposits, associated copper, lead, zinc, manganese massive sulfides, replacement copper, silver deposits, gold, silver, copper vein deposits, and some gemstones and lapidary material (i.e., fire agate, opal, chalcedony, quartz crystals, chysocolla, turquoise, wulfenite, geodes, etc). Overall, the copper state has many very attractive gold deposits described in various geological reports and thesis studies at the US Geological Survey, Arizona Geological Survey, Arizona Geological Society, and publications and geological thesis projects at various universities in the state.

Reports by the Arizona Geological Survey and USGS, and papers by Hausel (2010, 2011a, 2011b, 2013) and books (Hausel, 2019, 2020) provide summaries of the many gold deposits in Arizona. One of these gold deposits, known as the Moss, was reopened in 2018. The historical mine not only has significant gold mineralization left in-situ by early miners, but also appears to have very good potential for discovery of additional gold resources in the nearby area extending both east and west of the historical workings.

Moss and Mossback mines, San Francisco (Oatman) district, Arizona showing locations of 
anomalies (yellow pins) and lineaments (red lines). Google Earth

The Moss lies 2-miles, on-trend, west of the Mossback mine (inactive), 5.5 miles northwest of the Gold Road mine (active), 11 miles southeast of the Katherine gold mine in the Union Pass district, and is the northernmost extent of known gold mineralization in the San Francisco district of the Black Mountains. Nearby towns include Bullhead City (6-miles west), and Oatman (6-miles southeast). 

The Moss mine is located on the Moss vein: the vein, which has an N60oW-trend and 60o to 70oSW-dip. The mineralized structure is 45-feet wide locally, and pinches and swells along strike (Wilson and others, 1981). Gardner (1936) reports the structure to range from 20- to 100-feet wide: with mineralization in extensive stockworks and silicified zones. The deposit is described as epithermal, low-sulfide, quartz-calcite vein and stockworks system extending over a strike length of at least 4,500 feet (Nolan, 2010). Gardner (1936) indicates the vein could be traced for more than a mile along strike. 

The vein is hosted by Tertiary, Moss quartz monzonite porphyry (Gardner, 1936; Noland, 2010), with the structure being open along strike and at depth. In the past, shafts were sunk 100- and 230-feet deep with 1,700-feet of drifts. A calcite-quartz stockworks vein occupies the hanging wall of a high-angle fault and is overlain by as much as 100-feet of low-grade, mineralized, stockworks and siliceous breccia classified as low-sulfide, adularia-sericite, epithermal vein typical of many near surface, hydrothermal systems. Such deposits are often related to paleo-hot springs and/or shallow geothermal systems. The vein has some fluorite (Lausen, 1931). 

Along the southern portion of the vein, a group of conjugate veins occur in the hanging wall that have a similar trend, but dip northerly. Much of the historical gold and silver production from the vein was from conjugate veins. 

In the 1980s, Harrison Mining dewatered the shaft and mined 3,000 to 5,000 tons of ore that averaged 0.29 opt Au. In 2004, Patriot Gold Corporation optioned the property and identified auriferous veins unrelated to the primary vein that include the Discovery and Ruth veins. In 2009, Northern Vertex picked up the property and drilled more than 670 holes (Preston, 2013). 

Using a 0.01 opt cutoff grade, the Northern Miner reported the deposit has 22.6 million measured and indicated tonnes grading 0.023 opt Au and 0.26 opt Ag, plus 3.9 million inferred tonnes averaging 0.017 opt Au and 0.2 opt Ag. In total, known resources include 603,000 ounces of gold and 6.6 million ounces of silver within 650 feet of the surface (Preston, 2013, Wilson and Redwood, 2012). 

Holes drilled in the western extension of the vein were designed to test near surface quartz-carbonate stockworks open to the south. Multiple zones of stockworks veining (randomly oriented veins and veinlets, sometimes referred to as stinger zones) encountered within 500 feet of the surface, suggest potential for widespread mineralization to continue south. Eight additional drill holes demonstrate strong development of quartz-carbonate veins, breccia and stockworks that continue from the surface to at least 650 feet deep. 

An airborne magnetic survey by Patriot Gold indicates the Moss structure is a well-defined, magnetic high. The survey identified 1.8-miles of unexplored magnetic structure, and also identified nine linear structures associated with known mineralization, and one 3.6 mile structure was likely an extension of the Gold Road deposit. Recently, a heap leach pad was constructed south of the Moss vein (35°5'43"N; 114°26’55"W) presumably to extract gold from low-grade ore. Northern Vertex poured its first gold bar in early 2018. 

At the eastern extent of the mineralized zone, the Mossback mine lies along the edge of Mossback Wash. The property was claimed in 1863 and a shaft sunk to a depth of 800 feet. The vein is in andesite and as much as 90-feet wide with an 80o dip. Vein-filling consists of brecciated andesite and calcite with subordinate amounts of quartz, with spotty ore. In addition, the area appears to have an extensive gossan based on aerial photography (Hausel, 2020).

Recently, Elevation Gold Gold Mining Company published mineral resource estimates of gold and silver for the Moss mine as of December 2019. They report measured, indicated and inferred resources totaling 489,000 ounces of gold and 5, 838,000 ounces of silver. 

Elevation Gold optioned the Moss in 2011 and constructed a pilot plant in 2014. After construction and commissioning of the mill and mine in 2018, Elevation Gold announced commercial production at the mine, effective September 2018. 

The operation features a an open pit. The ore is crushed, agglomerated and heap leached followed by processing in a metal recovery plant and refinery, with a final process of production of gold and silver doré bars. 

An updated mineral resource estimate incorporating results of a 2019 reverse circulation infill drill program was disclosed in a December 18, 2019 press release. Drilling to the west of the current mining operation demonstrated there are significantly more resources within and adjacent to the open pit. 

"The resource estimate update found that from the start of operations to December 31, 2019, mining operations depleted approximately 71,000 ounces of gold, however with drilling success, these mined ounces have been more than offset by an addition of 86,000 ounces of gold in the inferred category. In comparing the updated December 31, 2019 resource estimate to the resource estimate in the Technical Report, aggregate measured and indicated gold ounces fell by approximately 8% primarily due to depletion from mining activities, while inferred gold ounces grew by almost 300% due to the identification of new resources from infill drilling. Exploration upside potential at Moss is excellent as the deposit continues to remain open for resource expansion along strike (at both ends) and at depth". 

TECHNICAL REPORT

Technical Report, 2021 on the Mineral Resource, Mineral Reserve, and Mine Plan for the Moss Mine

Goldfield Arizona - A Good Tourist Town.

The Goldfield district lies in the foothills of the Superstition Mountains at the extreme northeastern edge of the Phoenix valley, 5 miles northeast of Apache Junction and 40 miles east of Phoenix. The district extends from Pinal into Maricopa County along the margin of Arizona’s Transition zone within the Basin and Range province. 

Gold was discovered in 1892, and led to construction of Goldfield boomtown. The town was occupied by more than 1,500 residents with a post office established on October 7, 1893. The rush was short-lived. By 1897, many mines lost their glitter, and miners packed up and left Goldfield to the ghosts. 

But the ghosts were again haunted by miners and prospectors when a second community was established at the original townsite, and renamed Youngsberg. Mines re-opened, and a mill and cyanide plant built to recover gold, and a Post Office established on March 15, 1920, two years after the end of the first world war. 

But the mines again lost their attraction and the town was vacated in 1926, leaving it in the hands of ghosts. Today, the town has been revived by tourist trade and the town stands once again with both the living and the dead. The tourist attraction, a replica of the old mining town, provides exhibits of old mines, a brothel, saloon, museum, livery, gift shops, galleries, gold panning and more. You can even take a mine tour and sometimes see a gunfight. It is a highly recommended stop when visiting the Phoenix east valley, whether you are sentient or ghost.

Goldfield is accessed from Route-88 (North Apache Trail). Along the way, you will drive by the Superstition Mountains Museum. This is a highly recommended stop with old stamp mills, and information on the Lost Dutchman mine. After your museum tour, Goldfield is just another 0.8-mile up the road on the left. The Goldfield 7.5-minute quadrangle encloses much of the district and shows locations of some mines and prospects.

Wilson and others (1967) report that the district is covered by a pediment surface overlying coarse-grained granite, granite breccia, granite pegmatite and indurated (hardened) arkosic conglomerate. The principal mines in the district lie along north-trending, (west-dipping) shear zones (faults). 

The most productive mineralized zone at Goldfield was known as the ‘Mormon stope’ mostly mined out prior to 1898 at the Mammoth mine, north of the town. A stope was developed on an ore shoot, discovered north of the main Mammoth shaft at an intersection of a cross-fault with a shear zone, which provided permeability favorable for gold to flood the structure. The caved portion of the stope is 100-feet by 25-feet where granite is stained by limonite with irregular stringers of coarse-grained, white, quartz. Limonite (some gold-bearing) is likely derived from pyrite oxidation.

The district is best known for sporadic, fault-controlled, rich, ore shoots in large blocks of low-grade gold ore. During its heyday (1893 to 1898), the Mammoth, Bull Dog, and Black Queen mines produced about 60,000 ounces of gold and 20,000 ounces of silver. You can find out the value in present day's dollars by using links on Searching for Gold. 

There are no known reports of placer gold in the district other than a passing statement by Dinsmore (1911) stating that within a 3 by 8 mile area, “gold may be panned anywhere”. A sediment-filled arroyo crosses the mineralized structure to the north and west of Goldfield, and likely has some gold. Based on some of the reported high-grade zones in the faults, it is likely a few nuggets and gold dust lie buried in sand and banks of the arroyo (search Google Earth for ‘Goldfield, AZ’). Like most stream beds in the desert, it is rare to see standing water in this drainage except after rare downpours. Since the drainage receives runoff from the nearby Goldfield Mountains, flash floods are not uncommon. 

Gold was discovered in this area following a flash flood that exposed granite porphyry breccia containing visible gold. The granite was covered by arkosic conglomerate before it was exposed by the flood waters (arkose is a sedimentary rock with considerable quartz and feldspar and of similar composition as granite). Prospectors reported some very old mine workings were found in the area, indicating gold had been sought by unknown miners prior to 1892. 

The principal mines are the Black Queen, Bulldog, Mammoth and the Old Wasp; however, other mines and prospects were dug including the Bluebird, Doc Palmer, Copper Crown, Tom Thumb, Fairstake, Treasure Vault, Golden Hillside, Highflyer, Lazy Doc, Goldstake and Gold Bond. These are described by Hausel (2020).

The Vulture Gold Mine, Maricopa County, Arizona

Geologist and author Dan Hausel is presented a trophy
to decorate his tent while working at South Pass,
Wyomingin the 1980s. This trophy was proudly
displayed in his office at the University of Wyoming
 for many years - until it was passed on to the
director of the Wyoming Geological Survey
still attached to plumbing so it would appropriately
accept what the director used for brains.
The trophy originally read "Welcome Back Dan,
 District Geologist's office"

When prospectors and treasure hunters discuss gold prospects or mining in Arizona, the Lost Dutchman or Vulture is usually the central topic of conversation. But the Lost Dutchman gold mine, in my opinion, was never really lost. If it's not just a myth, I'll eat my ....  Well, what should I eat? Hmmm, I only have one hat and it is likely not tasty after traveling with me to the field for so many years; so let me think about what I'll eat just in case I'm wrong.

Anyway, gold mine legends are just that - legends perpetuated by old timers who usually initiate legends in the dark corners of local bars. They search for listeners hopeful of getting enough facts, so they can sneak out and get some of the old timers gold - but they always need another detail or two. So they buy the old prospector another beer hopeful of loosening his tongue just a little more. This goes on all night until the prospector or the listener finally passes out. Its a great way to get free beer and free dinners. 

I know what you're thinking - nope I never tried it. I don't need to make up a story. There are too many good gold prospects already out there so I don't need to make up one. And I already found more than $60 billion in gold (but didn't receive a dime of gold for the major gold deposits I found in the Rattlesnake Hills of Wyoming or the co-discovered monster gold deposit in the Kuskokwim Mountains of Alaska. Yep - more gold than was mined from the Homestake mine during its 123 year mining history - and I didn't get any of it! And this doesn't even include the diamond and colored gemstone deposits I found over the years (and didn't receive anything more than a salary). So, I'm not sure why anyone bothers with myths - there are too many real gold deposits out there to be found. But I've known characters who have perpetuated a story or two.

Years ago, while mapping the 250-square-mile South Pass greenstone belt and its mining districts and mines, I would spend evenings in the local bar - the Atlantic City mercantile and sometimes the TNT cafe, just to listen to the old prospectors. I would later head off to my tent to do some work under a Coleman lantern before heading back out to the field the next day. 

A 20 stamp gold mill on display near Apache Junction, Arizona

One prospector nicknamed 'Shorty', was just that, short. I really enjoyed talking to him as he had been a miner and prospector in the area for decades and even worked on the old Rock Creek dredge. I forget who told me the story, but Shorty had another nickname 'Wet Pockets'. I was puzzled by this nickname until it was explained Shorty worked in the Rock Creek washing plant when it was recovering gold in the 1930s until the outbreak of World War II. Apparently, it was discovered that his pockets were wet from high-grading gold off of the concentrating table, and he was dismissed. I don't know how much of that story was true, but Shorty was a very interesting character. Personally, I had a lot of respect for him. Even so, this could have been a start for another lost gold mine. How else could one explain finding those nuggets?

When I met shorty, he lived in a small, single wide trailer on the main drag of Atlantic City. He also owned a nearby gold mine. One day, he invited me in to talk about gold. At first, I couldn't quite tell, but there seemed to be a distinct odor. What was that smell? It reminded me of the building where my trophy came from, but I kept it to myself (not too long after this conversation, Shorty had a heart attack and passed on - many of us will miss one of the great prospectors of South Pass. His trailer was moved out of Atlantic City and sitting under the residence, right where he had cut a small hole in the floor, was a honey pot).

While talking to Shorty, he told me, he was the only successful prospector in the South Pass region over the past 60 to 70 years (I believe he was in his mid-80s at this time). It was apparently obvious I wasn't buying this, especially when I started looking around his tiny trailer thinking to myself - and why are you here?  As if he could read my mind, he stood up and reached in one gopher hole and pulled out a ball jar full of gold (now I wish I would have carried a camera). Then went to another cubby hole and pulled out another, then another. Wow! Now he got my intention. But do you see what could have happened here? He claimed to have mined all of that gold, but didn't make up a lost legendary mine.

The rugged Superstition Mountains, home of the Lost Dutchman legend, are
visible in the background. This rhyolite dome is the site where many people
end up being found by Search and Rescue because of the rugged hills and
intense desert heat. In foreground are the authors of the book 'GOLD'. 

Shorty was not the only character I met at South Pass. One of the great ones was Barbara. A tiny lady of possibly 90 pounds soaking wet. Barbara was a prospector who mined people's pockets and wallets at the Mercantile. If she could see you had gold fever - watch out, she would sell you just about anything. One poor sucker was looking for gold, so she sold him a bottle of gold. He was quite impressed at his investment until another prospector pointed out that his jar was filled with mica. Not sure how he took this information, but the Atlantic City volunteer fire department was called to put out a fire in Barbara's old Cadillac.

One day, a gentleman walked into the Mercantile dressed to the 9s. He apparently just got off an airplane in Riverton and drove to Atlantic City. Barbara thought she had recognized an opportunity and sat down with this well-dressed gentleman to try to sell him a gold mine - that's right, she was offering him a great opportunity to purchase the Mary Ellen gold mine at a bargain. However, Barbara took another shot from the bar after the gentleman told her that he already owned the Mary Ellen mine. Barbara too passed away a few years ago. Not sure if anyone knew her age, but she had lived a long time and, for those of us who did not fall for her scams, we all miss her and her antics.



Superstition Mountains in the background
from Goldfields, Arizona
(photo by the author).

So, back to the Lost Dutchman mine. In my opinion, the Lost Dutchman is just that, a myth chalked full of holes that has been embellished over time as any good legend should be. According to the legend, a rich gold vein was discovered by Jacob Waltz, a German immigrant, while prospecting in the Superstition Mountains east of Phoenix Arizona. If you’ve never been to Phoenix, the Superstition Mountains are the impressive volcanic dome that rises from the valley floor at an average elevation of 1,120 feet to vertical cliffs that reach a maximum elevation of more than 5,000 feet above sea level. From Apache Junction, the Superstitions rise as very impressive and rugged precipices.

The volcanic dome can be viewed on Google Earth: search for ‘Superstition Mountains, Arizona’. These rugged mountains are part of a 25 million year old, resurgent, rhyolitic dome and caldera. As you back out of Google Earth to an eye altitude of 30 to 35 miles, you should see evidence of an 8- to 10-mile diameter, circular structure: this is the dome. The dome is formed of rhyolite a volcanic rock that is the fine-grained equivalent of granite that occurs in a variety of colors, most notable light gray to white and reddish-brown to pink due volcanic rocks with abundant fine-grained pink feldspar. 

The Lost Dutchman's match box with inlay of milky
quartz filled with visible gold along the fractures.
The match box is described to have been made from
 Lost Dutchman gold mine ore (photo by the author). The
original photo is on display at the Superstition Mountains
Museum in Apache Junction.

According to historical documents, Jacob Waltz (the Dutchman) prospected the Bradshaw Mountains north of present day Phoenix from 1863 to 1867. When he later died at his home in the Salt River valley (Phoenix area) in 1891, legend claims a box was found under his death bed that contained 48 pounds of high-grade gold ore consisting of milky quartz with considerable visible fracture filling gold. An alleged sample of this ore was made into a match box and the woman who provided care to Waltz in his last days came into possession of a map of the gold discovery, which some sources report she sold copies for $7 each (a relatively high price in 1891).

Is there any truth to the Lost Dutchman legend? I’m no expert on the legend, but as myths go, they should be left to treasure hunters, used car salesmen, the Obama Administration, parapsychologists and brothels. The Lost Dutchman’s mine has never been found, but a rich quartz vein was discovered at the other end of the Phoenix valley in low-lying hills known as the Vulture Mountains. Records suggest the Vulture mine may have been the largest gold producer in Arizona in the historical past. And there may have been a connection between this and the Dutchman.

The Vulture mine became known for its high grade gold ore. Various reports suggest many thieves made a living high-grading ore from the mine (today, we call these people politicians). The problem was so rampant that some thieves were hanged at the mine site.

The Hanging Tree at Vulture City (photo by the author).

The history of the Vulture mine began with discovery of a vein along the southern flank of the Vulture Mountains in 1863 by Henry Wickenburg. The mine is situated 15 miles south of the town that bears his namesake. To see the mine and ghost town on Google Earth, search for ‘Vulture Gold Mine, Landing Strip, Wickenburg, Maricopa, Arizona 85390’. The mine is located west of the landing strip.

Henry Wickenburg and others were prospecting along the Hassayampa River (a dry river much of the year) to the east of the mine when they spotted a dark, iron-stained outcrop on a hill to the west. On close examination, they found visible gold in the outcrop. All of the prospectors except Wickenburg, were apparently unimpressed as only Wickenburg decided to file a claim on the vein.


Part of the Vulture quartz vein showing gossan (iron-stained rock)  (photo by the author).

Johnson (1985) reports some of Wickenburg’s initial samples assayed 6 ounces per ton gold. But instead of mining, he decided to sell ore to local prospectors for $15 per ton. These miners hauled ore to the Hassayampa River where the rock was processed in many arrastras set up wherever water could be found in the intermittent drainage. In 1866, Wickenburg sold his vein to the Vulture Mining Company and the company constructed a 40-stamp mill near the present town site of Wickenburg and gold was recovered from high-grade ore that ran 1.2 to 4.5 ounces per ton.

Early mine development focused on the western portion of the vein. Since the only water to be found was 15 miles from the mine, the site of the mill was based on the presence of water. The high-grade ore had to be hauled by wagon to the mill and high-grading occurred in the mine, mill and on the haulage wagons.

View of the old head frame at the Vulture mine (right) and vein (left).

In 1868, the western extension of the vein was mined by a separate operation known as the Smith group which built the Smith mill 10 miles east of the mine to process their ore: this mill had 20 stamps. At least three mills were initially constructed because of divided property ownership. The third mill was constructed 3 miles north of the Smith mill at Seymour (Hutchinson, 1921). In 1870, it was reported 300 miners were employed by mine operations and Vulture City had about 500 residents in total.

When the mine reached the 240-foot level (240 feet deep), a rich pocket of gold was intersected where the vein swelled to 47 feet wide. This shoot produced ore that contained 7 to 12.5 ounces per ton gold, suggesting a possibility of supergene enrichment, something common in many Arizona districts. Supergene enrichment occurs when oxygen-rich meteoric water leaches metals from near surface and transports the metal down through fractures by gravity until fluids lose oxygen (typically at groundwater level) and precipitating valuable metals to produce a zone of enrichment.

Remains of the Vulture mine and city powerhouse.

In 1872, the vein appeared to pinch out in the eastern portion of the mine and operations refocused on the western portion of the vein. In 1879, the Arizona Central Mining Company purchased the property and constructed a 16-mile long waterline from Wickenburg to the mine site and expanded mill operations with 80-stamps. Mining continued on the western vein extension until the eastern vein extension was rediscovered at depth.

Nine years later (1888), the vein was again lost. The vein was cut by a fault known as the Talmadge Fault that sliced the vein on the 300-foot level and the vein had been down-dropped to an unknown depth. At this time, mining operations were very limited and restricted to the western portion of the vein above the fault zone and it wasn’t until 20 years later (1908) that a comprehensive geological study was conducted that led to the discovery of the vein offset. The mine reopened and ore was again processed to recover gold on amalgamation plates while tailings were stored for later cyanide treatment. A new mill was constructed in 1910 that had 20 stamps with a capacity of 100 to 120 tons per day. Water wells were also drilled. One intersected groundwater in a gravel lens beneath a lava flow at 400 feet depth. Another well was drilled to 1,000 feet before hitting water (Hutchinson, 1921).

The mine operated until 1917 when the vein was again lost. This time it had been offset along a second fault (Astor Fault) on the 950-foot-level in the eastern portion of the mine. The Astor fault cut the vein also displacing it somewhere down dip.

Exploration for the offset vein began with the sinking of a 500-foot winze (an underground shaft) sunk from the 1050-foot-level. The vein offset was discovered on the 1,550-foot mine level and operations continued until the mine was closed by the War Production Board in 1942. At this time in history, the War Production Board closed all non-essential gold mines in the US to ensure maximum energy was directed towards the war effort. Many mines that were closed by this order never reopened, suggesting at today’s gold prices, many of these likely have commercial ore.

Tightly folded Proterozoic basement gneiss exposed at the
Vulture Mine.

Regional Geology. The Vulture mine sits at the southern edge of the Vulture Mountains 50 miles west-northwest of Phoenix. The basement (oldest exposed crustal rock) in this area is Proterozoic (2.5 to 0.6 billion year old) metamorphic and igneous rock (schist and gneiss) intruded by Cretaceous (145 to 65 million year old) granite and granodiorite that are all unconformably overlain by lower to middle Miocene (23 to 5 million year old) volcanic (rhyolite and andesite) and sedimentary rocks. All of these have been tilted by rotational (normal) faulting such that the original bedding is now near-vertical to overturned (Spencer and others, 1989). The Vulture vein is associated and related to the granite pluton. The mineralized zone at the Vulture mine is fault controlled with the vein trending east-west nearly parallel to foliation with a dip of 42oN.

The vein was traced 1,000 feet on the surface and is 32 feet wide on the surface. It is a complex of quartz and schist, such that mineralized quartz (about 6 feet thick) lies adjacent to footwall schist. This is overlain by chlorite schist followed by a large 30 to 50 foot thick quartz vein that includes low-grade white quartz and quartz with brecciated schist. The hanging wall is composed of chlorite schist and granite porphyry while the footwall is sericite schist. The vein was quarried on the surface in two, small, gossan-stained small open pits (Hutchinson, 1921; Wayne, 1985).

Vulture Vein. Gold mineralization occurs within and adjacent to a north-dipping quartz porphyry dike that extends eastward from the granite pluton. Gold is concentrated in quartz veins and in silicified and altered rock within and adjacent to the dike. The precious metal occurs as native gold or electrum and is also associated with pyrite, galena and minor chalcopyrite and sphalerite. There is a positive correlation between gold and secondary silica and sulfides. Granitic breccia clasts become progressively more common to the west in the vein. Where the vein extends into the granite pluton, it splits into smaller veins prior to pinching out.

The geology suggests ore shoots occur en echelon in the vein Another undeveloped shoot is proposed to occur further east and at greater depth that those mined in the past. In the area overlying this proposed ore shoot; surface rock exposures include Miocene volcanic tuffs and lavas which cover the old schists and gneisses. The metamorphic rocks are again found 3,000 feet further east where they show some evidence of mineralization (Hutchinson, 1921). The faults which offset the Vulture vein are not exposed at the surface and are buried under gravel and lava.

Glory Hole open cut at the Vulture gold mine looking to the east towards the ghost town.
The rocks are stained with limonite giving them a slight yellow appearance,
while along the right side of the photo is part of the exposed Vulture vein with
bluish-green chlorite schist.

Pervasive wall rock alteration adjacent to the vein resulted in replacement of feldspar and mafic (dark) minerals by sericite, hematite and clay. The gold was reported to be 760 to 780 fine (White, 1988).

Production. Production figures are incomplete. Available reports indicate the mine produced at least 340,000 ounces of gold and 260,000 ounces of silver from ore that had an overall average grade of 0.35 opt gold and 0.25 opt silver (Spencer and others, 1989; White, 1988).

Current Activities. In recent years, there was an effort by preservationists to push the State of Arizona into purchasing the Vulture mine and ghost town and withdraw the property from mining. Such activities tend to set a dangerous precedent in letting government nationalize private property and control private land and businesses. Such activities lead to corruption and mining companies avoiding some states and regions.

Old assay lab at the Vulture gold mine. In the upper part of the wall, one can
see the old bricks used to construct this building. Legend suggests it is
constructed from rich quartz vein ore from the mine and contains
considerable gold.

This happened in Wyoming. The Wyoming state legislature purchased the principal historical gold mine in the South Pass region without consulting the Wyoming Geological Survey. The Carissa mine was incorporated into the South Pass City historic site essentially taking a sizable ore body from the public sector. The Carissa likely has tens of thousands to a few million ounces of gold. Work by mining companies and the author showed the presence of a ore body that was a minimum of 1,000 feet long, 300 to 1,000 feet wide and more than 970 feet deep (likely a few thousand feet deep) that may have provided jobs and attracted gold exploration in the region (Hausel, 1991, Hausel and Hausel, 2011).

Purchasing a commercial ore body by the legislature with taxpayer funds stymied gold exploration throughout South Pass. Previously, the Willow Creek placer adjacent to the Carissa mine was taken by the State under the guise it contained abundant toxic chemicals. Now the preservation effort is spreading to the nearby Duncan gold mine.

Mine adit at the Vulture mine dug into fanglomerate. I could not find any reports of gold mined from this conglomerate or from nearby drainages, but it would be one place I would look for gold since it sits adjacent to the Vulture vein.

For now, Arizona’s Vulture mine appears to have weathered the effort to have the State of Arizona purchase private property and more recently, the property was optioned by a Canadian company: Source Gold Corporation.

A real 'LOST' gold mine. The Carissa gold mine sits on a major gold-rich
shear zone that likely hosts several million ounces of gold. The mine was
lost in a legislative takeover of public property. The Wyoming legislature
purchased to gold mine and incorporated it into the South Pass City historical
site so it could never be mined again. This purchase followed research by the
author that showed a mineralized structure that is about 970 long by nearly
1,000 feet wide that likely continues to several thousand feet deep that
contains gold. Drill intercepts to more than 900 feet intersected rich gold
shear zones.

Conclusion. The Vulture mine never reopened after the Second World War leaving one to wonder how much gold remains unmined. There appears to be very interesting connection of the Vulture mine to the Lost Dutchman mine. Some reports suggest that Jacob Waltz (the Dutchman) worked as a miner at the Vulture for several years. Could he have been one of the many high-graders who collected gold specimens from the mine? Could this be the source of the legendary Lost Dutchman gold mine in the Superstition Mountains (Johnson, 1985)?

References
Hausel, W.D., 2012, Arizona's Vulture Gold Mine and Lost Dutchman: ICMJ Prospecting and Mining Journal, v. 81, no. 9.

Hausel, W.D., 1991, Economic Geology of the South Pass Granite-Greenstone Belt, Wind River Mountains, Western Wyoming. Geological Survey of Wyoming Report of Investigations 44, 129 p.

Hausel, W.D., and Hausel, E.J., 2011, GOLD - Field Guide for Prospectors and Geologists. CreateSpace, 366 p.

Gold vault at the Vulture mine, Arizona.

Hausel, W.D., 2019, Gold in Arizona - A Prospectors Guide: GemHunter publications, 350 p.

Hutchinson, W.S., 1921, The Vulture mine, Engineering and Mining Journal, v. 111, no.7 p. 2-12.

Johnson, Wayne, 1985, The Vulture: California Mining Journal, Oct., p. 8-11.

Spencer, J.D., Raynolds, S.J., Grubensky, M.J., Duncan, J.T., and White, D.C., 1989, Geology of the Vulture gold mine: Arizona Geological Survey, Arizona Geology, v. 19, no. 4, p. 1-4.

White, D., 1988, Geology of the Vulture Mine Arizona: AIME Preprint 88-44, 5 p.