Thursday, May 30, 2013


Map of Cochise County, Arizona, showing localities around Gleeson, Courtland, and Dos Cabezas.  Map from Stephen Christian.  
The State of Arizona has a long history of mining activity with resulting "ghost towns" and abandoned mines.  Over the years I had some opportunities to visit mines and collecting areas and along the way found a few of the semi-abandoned towns.  Unfortunately, many/most of these old mines are posted and/or closed to individuals collectors.  For example, the Courtland-Gleeson-Pearce area east of Tombstone is often listed under the category of “ghost towns” and old mining districts. 

Pearce was a gold mining town and the Commonwealth Mine produced over 15 million dollars in gold (much more at today’s prices) in the late 1800’s and early 1900’s.  The boom town had a 200-stamp mill but a 1904 cave in at the Commonwealth was the “beginning of the end”.  The town barely hung on until the Great Depression when the town finally folded, or almost.  Today there is some movement in the area with new business and restored buildings and attempts are being made to attract tourists. 
Gleeson was the site of copper, and some lead and silver, production in the late 1800’s and early 1900’s.  In fact, a gentleman in Tombstone told me that the area had produced in excess of 75,000 oz. of gold.  Let’s see, at ~$1400 oz. that amounts to ……!!  The town suffered greatly due to a fire in 1912 and that event, plus the “playing out” of the rich copper ore, was a death call for the town.  However, some activity is still going on due to the small scale mining of turquoise.  In fact, the original name of the town was Turquoise; however, the stone was not really valued in those early mining days.

Courtland came about a few years later as surficial geological clues indicated an extremely rich copper ore body and for a time in the early 1900’s the area was thought to have the most promising copper vein in Arizona.  Two railroads served the area and by 1909 four major mining companies had constructed in excess of 8000 feet of underground shafts and the ore was being mined at ~7.5% copper.  Newspapers opened up and by 1911 over five miles of water mains were in operation---the boom was on (2000 people).  By 1920 the mining companies were losing money and the town literally disappeared!  It seems as the “mother lode” disappeared at about the 300 foot level, probably the result of faulting, and, the mines also were flooding.  Above information on the district is from Ghost Town Trails (2011).

Mineralization at Courtland-Gleeson-Pearce is of several types: (1) copper carbonates and oxides in irregular blanket deposits where the Cambrian quartzite is thrust over Mississippian limestone creating a fault breccia (broken rock) close to a contact with an igneous intrusion; (2) lead and zinc carbonates, lead sulfates and zinc silicates with silver chloride, manganese and minor copper and gold in irregular ore bodies in Pennsylvanian-Permian limestones along fractures and faults; (3) turquoise in near-surface stringers and lenses in altered granite and quartzite—solution in fracture zones; (4) manganese oxides in irregular masses along fractures in limestone; and (5) spotty base metal ores with gold and silver values in veins located in intrusive rocks (MinDat, 2011).  What all this means is that faulting in the area created fracture zones that allowed heated (from the igneous intrusions) and mineralized solutions to travel through and deposit the metallic ores.

I was intrigued by geologic descriptions of the area and of the many mines and recovered minerals.  However, upon traveling to the mining areas I was disappointed in that essentially all of the land is private and I could not locate owners who would allow me access.  However, I was able to purchase a nice piece of polished turquoise labeled “Courtland”. 
Turquoise polished slab, ~4.5 X 4.5 cm., labeled “Courtland”.  Turquoise is a secondary mineral caused by an alteration of rocks rich in aluminum.
A similar situation (private land without access) occurs to the north in the Dos Cabezas Mining District, an area that was booming in 1880’s.  Wilson (1927) stated “practically all the gulches in the vicinity contain gold-bearing gravels”.  That statement was enough to get me off and running to the area.  The Dos Cabezas Mountains are a typical “Basin and Range” horst (uplifted block of mountains with down-dropped valleys on either side).  The mountains have a wide array of rocks cropping out ranging from Precambrian granite to Paleozoic and Mesozoic rocks to Tertiary volcanics and intrusive.  However, it seems the entire area is covered with no trespassing signs and the land owners I could locate are quite unfriendly.  Perhaps they are just tired of out-of-state treasure hunters?  I did manage to grab several bags of sand from along the road (without trespassing) but was unable to confirm Wilson’s statement about the gold.

Two “ghost towns” that are friendly to visitors include the settlements of Charleston and Fairbanks; both are managed by the Bureau of Land Management (BLM) so collecting, including metal detectors, is off limits.  These towns grew up along the San Pedro River in southern Arizona due to the proximity of the mines at Tombstone.  It seems as if Tombstone, 10 miles away, suffered from a lack of surface water so several stamp mills were established at Charleston and one at Fairbanks; ore was hauled by wagon.  A railroad was constructed to the mill towns and later two more were added.   Fairbanks, six miles north of Charleston, became a major train stop between Guaymas, Mexico, and Benson, Arizona.  The Fairbanks depot became a major transport area with the travelers coming and going from Tombstone, and cattle being shipped out of the area.  Both communities were thriving towns in the late 1800’s, but they owed their existence to the rise and fall of Tombstone’s fortunes. Fairbanks existed into 1900’s; Charleston was essentially destroyed when the U. S. Army used the buildings as a training base in World War II.  

Fairbanks, Arizona ca. 1890. Photo courtesy Arizona Historical Society.

Both communities are part of the San Pedro Riparian National Conservation Area (NCA) with a mission of enhancing and protecting the ecosystem along the river.  The NCA is managed by the BLM and the agency is slowly restoring many of the well-preserved buildings in Fairbanks.  I have visited the communities and have hiked along the river for many miles and have found the area fascinating.  First, the river is unique (at least to me) in that it flows north from Mexico into the U. S.  Therefore, it offers an interesting bird flyway with several tropical species fluttering north; one of my favorites is the Vermillion Flycatcher.  Second, the river flows in a large graben and is filled with late Tertiary lake and stream sediments and sedimentary rocks.  These units have produced a spectacular array of vertebrate fossils, hold the Desert Roses near St. David (see Blog posting February 4, 2013), and are the source of the glauberite pseudomorphs near Camp Verde (see Blog posting September 2, 2012).  And finally, the community of old Fairbanks is well-preserved and the buildings contain much history.  You can locate the old cemetery and stamp mill at Fairbanks and some of the old mining structures at Charleston.  Until visiting the area I had always assumed, although not much personal thought was given to the matter, that Tombstone produced its own stamp mills!  An erroneous thought!
Remains of Rockland Hotel at Sasco.
One of the more interesting accessible “ghost towns” to visit is Sasco, an acronym of its parent company, the Southern Arizona Smelter Company.  The town was established as the smelter site for the mining operations at the nearby Silver Bell mining complex.  Silver Bell was the site of major copper mining in the late 1800’s (minor silver, gold and lead) but seemed to suffer from a lack of potable water.  In the very early 1900’s the owners built a new smelter about 10 miles away and named it Sasco. By 1904 the Arizona Southern Railroad was built from Silver Bell to Sasco and on to Red Rock and Sasco boomed with over 600 residents.  Numerous buildings were constructed including houses, hotels, a jail, post office and several saloons.  Unfortunately, mining at Silver Bell went south and the smelter closed in 1919 and Sasco started its demise.  Today Sasco is vacant but there are really good remnants and foundations of the former buildings are numerous.  Unfortunately the site has been trashed—literally and figuratively.  Visitors have hauled in a tremendous amount of trash and debris and the ground is littered with shell casings.  Paintballers have discovered the place and walls are covered with the remains of the spent balls.  It is unfortunate that Arizona and/or BLM passed up the opportunity to stabilize an area of important historical aspect.
Railway (tracks on top of concrete pillars) ore dump at Sasco.  Railroad with ore came in from west (up) and dumped ore (right) where it was hauled a short distance to the smelter.
Silver Bell, the original town at the mine has been completely destroyed since ASARCO begin open pit operations in 1954 and continues today as a major copper producer.

I was able to poke around in the desert and dumps and actually came up with some interesting specimens: azurite [Cu3(CO3)2(OH)2] and malachite [Cu2(CO3)(OH)2], chalcanthite [CuSO4·5H2O], turquoise [Cu(Al,Fe3+)6(PO4)4(OH)8·4H2O], and what I believe is chalcoalumnite [CuAl4(SO4)(OH)12·3H2O].

Chalcanthite (A: ~3.5 cm.; B: ~3 cm. length), a hydrated copper sulfate found in the oxidized zone of copper deposits. 

Encrusting (on calcite) botryoidal ?chalcoalumnite, a hydrated copper-aluminum sulfate.  Length of light green encrustation (lower part of rock) ~7 cm.

Azurite and encrusting malachite, both hydrous copper carbonates.  Specimen ~5 cm. in length.
Ghost Town Trails (2011):

Wilson, E.D., 1927, Arizona Gold Placers, 2nd. ed. (revised), University of Arizona Bull. 124: 51