Saturday, October 22, 2016


Lord, I was born a ramblin' man,
Tryin' to make a livin' and doin' the best I can.
And when it's time for leavin',
I hope you'll understand,
That I was born a ramblin' man.

Allman Brothers Band

I had the opportunity to leave my position in academe 10 years ago and did so hoping, like most “retirees,” that our financial planning and frugality would yield financial rewards lasting throughout our life.  So far, so good!  I was experiencing some good times at my institution and wanted to leave on a high note---and because it was almost time for an accreditation review.  Few persons who have experienced higher education would say they enjoyed reviews by the various accreditation groups.

I also decided that although I was in late middle age---maybe?  Is 60 the new 40?  There was a plethora of “things” that interested me—from hiking 14ers and 13ers to reading to relaxing at morning coffee to some low level consulting to fishing to camping to traveling to etc.  After about six months I discovered that relaxing was getting boring and decided to try some new projects---writing popular geology articles (like this Blog with an easy editor), learning about new areas (like western US history), and trying to better understand “minerals and rocks.”  I was not a stellar student in my college mineralogy and petrology classes and perhaps wanted to redeem myself?  But traveling was always in the back of my mind as it had played a major part of my life as a field geologist.  I was now free to hook up the travel trailer (no more hard ground and tents for me) and head out at about any time of the year—I was born a ramblin’ man!

As noted in my previous post, in September 2016 we were able to spend three weeks in the Black Hills of South Dakota---Road trip.  Bring out the 60s CDs and turn up the radio:
Get your motor runnin'
Head out on the highway
Lookin' for adventure
And whatever comes our way

Spearfish Peak, a Tertiary intrusion dominating the southeast skyline of Spearfish.
I was excited about this down time opportunity as I needed to catch up on my rest and try to put my upcoming knee surgery way to the back of my mind.  I had a complete knee replacement about 17 months ago; however, the results were less than satisfactory and I needed some tweaking and cleaning and maybe the insertion of a grease zerk for a periodic infusion of wheel bearing grease!  Not what I wanted to do during the colorful fall season; however, I remain pleased that new body parts are available.
Not a torture device but a photo of arthroscopic knee surgery to reduce scar tissue (courtesy of  The S is an inserted scope to guide the surgeon while RR represents miniature roto rooter devices with small razor blades attached to the business end.  At least that was one description.  Fortunately I could not observe the procedure as magic meds had put me in la la land.

Index map of northern Black Hills.  Spearfish is noted with T indicating Tetro Rock, M: Maitland; C: Carbonate Camp; G: Galena; RT: Ragged Top.  Consult a topographic map or Google Earth for more detailed locations.
The first part of my expedition was headquartered in Spearfish, a quaint and progressive town in the northern Hills not far from the rambunctious gambling community of Deadwood.  FS 195 road leads out of town and heads south along a really colorful creek.  It then meets Maitland Road (gravel) and heads south to Lead and Central City---a sort of back road to the mining communities.  The conical Spearfish Peak (a very large sill, I think, with almost laccolith qualities; Blog Posting 9-5-13) is the dominant feature on the west side of the road; however, another more elongated peak becomes visible to the east---Tetro Rock at 5562 feet. Tetro, like many other Tertiary intrusions in the northern Hills, is composed of an igneous rock called phonolite: fine-grained groundmass of orthoclase feldspar and aegirine with ~45% phenocrysts of large crystals of feldspar (~2 cm) and pyroxene (8 mm) crystals; tiny (1 mm) of nephaline and sodalite.  The intrusive structure is probably a sill intruded along bedding planes in the Ordovician-Cambrian Deadwood Formation (Lisenbee and others, 2013).

The large Tertiary intrusion known as Tetro Rock.  Photo courtesy of Google Earth ©.  The Red Valley (Spearfish Formation) and the community of Spearfish in background.
A few miles down the road from Tetro Rock are remains of mines in the Maitland Mining District (Garden District) along False Bottom Creek.  The earliest mining activity probably started in the 1880s; however, the major production of gold and silver commenced in 1902 with the opening of the principal Maitland Mine.  In 1942 the Maitland was closed (due to the country’s effort in WWII) but had produced at least 176,000 ounces of gold.  The mineralization is a replacement gold deposit in the quartzite and dolomite units of the Deadwood Formation (Cambrian-Ordovician) with mineralizing fluids associated with nearby Tertiary intrusions.

 Google Earth © photo of the Maitland Mining area. Maitland Road comes in from lower left.

The above two photographs show remnants of structures associated with one of the Maitland mines.
Igneous rhyolite of Tertiary age intruded into the sedimentary Cambrian-Ordovician Deadwood Formation.
Manganese dendrite on a piece of the Deadwood Formation.  Width FOV ~3.5 cm.

Flow-banded rhyolite.  Width FOV ~20 cm.
Lisenbee and others (2013) mapped the igneous rocks associated with the Deadwood Formation at Maitland as rhyolite and latite, both fine-grained igneous rocks appearing as intrusive sills.  The mineralizing fluid migrated to the Deadwood via fractures and faults.  As best that I can tell, prospectors followed the contact between the igneous sills and the Deadwood digging small shafts along the way hunting for mineralization.  The Deadwood disappears under the middle Paleozoic limestones near Tetro Rock to the north and prospecting stops (Lisenbee and others, 2013).  I located a company project report indicating that Dakota Territory Resource Corporation has proposed a new mining project (Blind Gold Project) running from Maitland south to the Lead area (Cole and Smailbergovic, 2013).  They noted the “Maitland Mine was the last and furthest north of a string of mines that produced ore from the Deadwood Formation on a well-defined structural trend influenced by the fabric of the Proterozoic metamorphic basement.”  It will be interesting to see the results.

A small wooden structure along False Bottom Creek that the property owner told me was an original building from the mining era.  he also informed me that this area was the site of a stamp mill.

Bioturbated (note structures appearing to be animal burrows) rock slab of Deadwood Formation.  Penny for scale.
There is a small cluster of homes in the Maitland community along the creek (a gazillion other ranchettes are up in the hills) and a side road, named either the Carbonate Road or the False Bottom Creek Road, trends west to the old mining area of Carbonate Camp.  The name comes from ore mineralization in the middle Paleozoic Pahasapa Limestone rather than the Deadwood Formation.

In the Carbonate District, the Pahasapa has been intruded extensively by Tertiary sills and dikes. Wimorat and Patterson (1989) noted two different types of ore bodies: 1) fissure veins with gold-bearing iron gouge in the center and lead-silver rich (galena, cerussite, and cerargyrite) mineralized jasperoids (silica) along the margins; and 2) solution cavity-filling ores that are usually closer to igneous intrusions, are less siliceous than jasperoid, and are rich in lead and silver with minor gold.

The major minerals produced at Carbonate were silver, lead and gold with the best production for less than 20 years from ~1880-1900 (peak years 1885-1991).  The larger Iron Hill Mine, in the southern part of the District, hung on until ~1930.  In the late 1880s Carbonate Camp was a booming town with numerous businesses, including banks, newspapers, stores, mills, smelters, saloons, the largest hotel in Dakota Territory, and hundreds of residents. By the early 1900s diphtheria, other illnesses, fires and falling silver prices sounded the death knoll for the community.
It is hard to find production figures; however, Shapiro and Gries (1970) stated that in the peak six years the various mines produced 83 ounces of gold, 18,511 ounces of silver, and 83,191 pounds of lead.  Carbonate Camp was not a major gold producer.

Today the casual visitor might not even notice that a thriving town once existed in the area.  Maybe casual is the wrong word since visitors most likely are aiming for Carbonate Camp on ATVs or high clearance (preferably 4-wheel drive) vehicles.  The road can be very rough and rocky and the forest has reclaimed most of the old town.  I spotted some hewn logs, a few rotting log foundations, perhaps some collapsed mine shafts (the ole knee prevented much hiking), but nothing spectacular.  To the south the Iron Hill Mine (I think) looked reclaimed and No Trespassing signs were common.  Nature has its way of taking back localities of desecration and healing the land.
The forest has reclaimed much/most of Carbonate Camp although some structures may be identified as "human" in origin.
The best known road leading out of Spearfish is US 14 alt. trending south along a Blue Ribbon trout stream, Spearfish Creek (Trivia note:  trout species are not native to the Black Hills).  The canyon itself is absolutely gorgeous in all seasons, but especially so in the fall.  The canyon and stream dissect a large plateau of Mississippian Pahasapa Limestone; however, interrupting the plateau are numerous small-to-large, Tertiary igneous intrusions.  One intrusion that many visitors notice is Ragged Top Peak/Mountain towering above the creek and reaching 6220 feet in elevation while next door Elk Mountain comes in as 6422 feet.  What most visitors do not realize is that in the 1880s Ragged Top was the site of a booming mining community and several small towns and settlements. The major mines were generally north of Ragged Top but several other prospects were located west of the intrusion.  The production, mostly gold with some silver, came from vertical fractures in the limestone where mineralized fluid from the nearby intrusions had left behind the metals.  As with many of these boom towns, major production lasted less than 20 years with final closing ~1915.  It is difficult to estimate production; however, Allsman (1940) noted production from the mines operated by Spearfish Gold Mining and Deadwood Standard was nearly 50,000 ounces of gold from 1899-1914.  In mid-October 2016 spot gold prices ranged from ~$1250-1300 per ounce.  That calculates out as over $62,500,000; however, I have no information on the production costs. I do understand that some operators are looking at the deposits at Ragged Top, and Carbonate, for development of “heap leach” (cyanide) mining. 
 Google Earth © photo of Ragged Top Mountain along Spearfish Creek.

Igneous rocks exposed on flanks of Ragged Top.  Cloudy and misty morning and a telephoto lens do not allow for good photos.
Lisenbee and others (2013) indicated that Ragged Top is a sill and/or dike(s) intruded along bedding planes in the Deadwood Formation.  Someday I am going to try and find out the “whys” of these Tertiary bodies and their intrusions into the Deadwood Formation.  For example, some of the intrusions are not sills but actually laccoliths that domed up the overlying Paleozoic rocks.  Other intrusions deposit minerals in the middle Paleozoic Pahasapa Limestone Why?  I did note that Paterson and others (1989) believe isotopic compositions of minerals indicate “element sources in [both] the Precambrian rocks and Tertiary intrusive rocks.”  Some of life’s persistent questions?

The final stop in my little tour of old mining communities in the northern Black Hills was at the community of Galena (I love it when communities are named after minerals), south of Deadwood on US 385 for a few miles, crossing Strawberry Hills and then turning east (for ~3 miles) on FS 534 and then FS 534A.  Galena is a very active community with both permanent homes and seasonal “cabins.”  In addition, the 1882 school house is well preserved as are some other older buildings.  Unfortunately, it is difficult for a seasonal visitation by an ole geologist to acquire permission to explore the mines! 
Restored miner's cabin at Galena.
In previous posting I wrote about how Custer’s 1874 expedition, along with his “discovery” of gold, created a mining rush in all parts of the Black Hills.  Although it was illegal for non-Native Americans to enter the Hills, hundreds/?thousands of prospectors tried.  In 1875 Partick Donegan and John Cochran “snuck” into the future Galena, found silver-rich galena, and staked a claim.  They were then arrested and shipped away!  By July 1876 the Merritt Brothers had entered “Galena,” staked a claim about 100 feet above Bear Butte Creek, and started mining galena (probably argentiferous) and silver.  By fall 1876 the “sneakers” Cochran and Donegan had returned to Galena and formally filed their Sitting Bull claim about 200 feet above the Creek.  But remember all of the miners and prospectors were breaking the law as it was not legal to settle in the Hills until February 1877.  Who cares about decrees from Washington D.C. when “gold” is available for the easy taking.

As with many gold/silver/lead prospects in the northern Black Hills, the mineralizing fluids are associated with the Tertiary intrusives---with metal formation in the bedding planes, cracks, crevices and vugs of the Deadwood Formation.  The intrusives at Galena are composed of numerous sills and dikes that contain a wide variety of rocks with a fine-grained groundmass sprinkled with feldspar phenocrysts.

There were two major “pay zones” of horizontal argentiferous galena producing at Galena: 1) the Lower Contact about 100 feet above Bear Butte Creek (the Merritt brothers’ claim) and 2) the Upper Contact about 400 feet above the Creek (Cochran and Donegan’s Sitting Bull property).
By the early 1880s Galena had numerous hotels, stores, a smelter or two, several mines, boarding houses, stamp mills, ore roasting ovens, saloons, newspapers, physicians, barber shops, a telephone line; with rail service arriving  in 1902.  The place was booming. However, as with many boom towns of that era production begin to decline---too many corporate fights and law suits, the 1893 drop in silver prices, production costs, price of equipment, etc. The “good times” periodically returned to Galena but never remained for a long period of time.

The original Galena District along Bear Butte Creek produced mostly silver and lead although the ore minerals varied.  For example, the Sitting Bull properties yielded much silver from oxidized minerals in the Upper Contact zone while the Double Rainbow immediately below on the Lower Contact yielded silver from primary sulfides.

In addition to the Bear Butte mines (silver and lead) producing from zones in the Deadwood Formation, other properties in the District (i.e. Gilt Edge) produced gold from brecciated rocks and fracture zones in Tertiary trachyte and quartz trachyte porphyry.  Add those two gold occurrences to the Homestake mine producing from Precambrian rocks, and Carbonate and Ragged Top producing from the Pahasapa Limestone, the Tertiary intrusions and their associated fluids are responsible for the major occurrences of gold, silver and lead in the northern Black Hills.
And that leads me back to George Armstrong Custer and his 1874 Expedition to the Hills.  I noted in the previous Posting that an African American woman by the name of Sarah Campbell, but usually known as “Aunt Sally”, was part of the Expedition and an original claimant on the French Creek gold claims.  I also stated that she was one of the few members of the Expedition to return to the Black Hills.  In fact, she settled in Galena and is buried in the town’s Vinegar Hill Cemetery. 
Photo courtesy of Chuck James via
Road trips for field geologists or biologists almost are always enjoyable.  There are so many rocks to see, birds to identify, streams to fish, trails to hike, and memories of more youthful days to recount.
On the road again -
Just can't wait to get on the road again.
The life I love is [hiking] with my friends

And I can't wait to get on the road again.
On the road again

Goin' places that I've never been.
Seein' things that I may never see again

And I can't wait to get on the road again.
On the road again –
Willie Nelson


Allsman, P.T., 1940, Reconnaissance of gold-mining districts in the Black Hills, S. Dak.: US Geological Survey Bulletin 427.

Cole, B. and A. Smailbergovic, 2013, Technical Report on the Blind Gold Project, Maitland Mining District, Lawrence County, South Dakota: Dakota Territory Resource Corporation, Reno, Nevada.

Lisenbee, A.L., J.A. Redden, M.D. Fahrenbach, and K.A. McCormick, 2013, Geologic Map of the Savoy Quadrangle, South Dakota: South Dakota Geological Survey 7.5 Minute Series Geologic Quadrangle Map 20.

Lisenbee, A.L., J.A. Redden, and M.D. Fahrenbach, 2013, Geologic Map of the Spearfish Quadrangle, South Dakota: South Dakota Geological Survey 7.5 Minute Series Geologic Quadrangle Map 21.

Paterson, C.J., A.L. Lisenbee, and J.A. Redden, 1989, Gold deposits in the Black Hills, South Dakota in Paterson, C.J. and A.L. Lisenbee, Metallogeny of gold in the Black Hills, South Dakota (T.B. Thompson, Ed.): Society of Economic Geologists Guidebook Series Volume 7.

Shapiro, L.H., and J.P. Gries, 1970, Ore deposits in rocks of Paleozoic and Tertiary age of the northern Black Hills, South Dakota: US Geological Survey Open-File Report 70-300.

Wimorat, M. and C.J. Paterson, 2007, Carbonate-hosted Au-Ag-Pb deposits, northern Black Hills in Paterson, C.J. and A.L. Lisenbee, Metallogeny of gold in the Black Hills, South Dakota (T.B. Thompson, Ed.): Society of Economic Geologists Guidebook Series Volume 7.