BLACK HILLS: FUN AT BUFFALO GAP W/ UNKPAPA SANDSTOME

 

Author unknown.

In spring 1965 I made a critical decision or two—what to do with my life after college graduation (BS Geology).  I had pretty much decided during the fall semester that I wanted to continue my geology education; there was much to learn, and I was excited to explore the opportunities. So, I applied for admittance to several graduate schools with the knowledge that I could not continue my education without financial scholarship/fellowship assistance.  Much to my surprise I received some positive replies.  These offers came from a variety of institutions ranging from giant NCAA Division 1 institutions down to smaller state and private colleges.  That led to my critical decision in spring 1965—to attend the University of South Dakota in Vermillion (a college town that I really had never heard of)! So, it was off to the north land (at least north of my home in Kansas).

 Getting ready for the Homecoming parade on the main street of Vermillion, SD ca. mid 1960s.  Photo courtesy of southdakotamagazine.com

The decision to attend USD was one of those that was a “good one.”  Absolutely no regrets.  I was a small-town kid who attended a smaller state undergraduate college and USD was situated in a small town and was full of small-town kids and a small graduate program—I think there were five of us.  Students  got much attention from the faculty.

 

Back in the olden days, that would be late 1960s, the Charcoal Lounge (AKA Char Bar) was one of the anchors in downtown Vermilion (as seen in this 2017 photo--it looked the same in 1965).  The Char Bar was a 21 establishment since it served "hard liquor."  That meant the underclassmen were relegated to the "beer bars" such as the Varsity.

 

My roommate at USD for all two years was a small-town kid from nearby Minnesota.  After graduation from a doctoral program, he had a very successful career with South Dakota School of Mines and Technology.  During my recent trip to the Black Hills of South Dakota my mind drifted back to our grad school days as I drove through Buffalo Gap in the southern part of the Hills near Hot Springs.  My current journey to that part of the Hills was three-fold: 1) to relive, at least in my mind, some of the field work associated with my thesis; 2) to see if the Unkpapa Sandstone quarry was still open in Calico Canyon near the mouth of the Gap; and 3) to observe some nice roadside pegmatite exposures near Wind Cave National Park.

 

Google Earth© image of the start of Buffalo Gap with Custer County 101 following Beaver Creek westward.  The major highway is SD 79 coming north from Rapid City and heading south toward Hot Springs.  Calico Canyon, home of the Unkpapa Quarry, is the first major canyon coming off CC 101.

 

Unfortunately, the quarry had closed several years ago, and current landowners may not be interested in reopening.  Fortunately, I had visited the quarry back in the 1960s and have a few sandstone specimens stuck on my rock shelf.  What is so special about this sandstone?  For starters, who could resist looking at rocks named the Unkpapa?  The name was assigned to the stratigraphic unit by the famous geologist N.H. Darton as he studied and mapped the Hills in the early 1900s.  “The type locality is in the ridges east and south of Hot Springs, Fall River Co, SD, on the Chadron arch in the southern Black Hills, where it reaches a thickness of more than 250 ft. The name is from Unkpapa Peak, sec 23, T6S, R6E, Custer County, SD near Buffalo Gap.” (Darton and others, 1909).  Actually, the word Unkpapa is a misrepresentation of  Hunkpapa (Lakota: Húŋkpapȟa), one of the seven members of the Lakota tribe. The name Húŋkpapȟa is a Lakota word, meaning "Head of the Circle.  By tradition, the Húŋkpapȟa set up their lodges at the entryway to the circle of the Great Council when the Sioux met in convocation. They speak Lakȟóta, one of the three dialects of the Sioux language. (Access Genealogy, 2021). Sitting Bull (Tȟatȟáŋka Íyotake) and Gall (Phizí) were two well-known members of the Hunkpapa.

Second, the Calico Quarry has produced  some fantastic specimens of banded sandstone described by Joe Hartman (1975) as “argillaceous, very fine-grained, massive quartz wacke sandstone; moderately indurated but friable, permeable, no indication of cement. Colors range from pale yellowish orange to grayish orange to pale red purple to pinkish gray. Color banding common, planar, curved, and Liesegang.” The emphasis is mine as the rock produces slices commonly known as picture sandstone and at one time specimens were sold in virtually every rock shop and curio shop in the Black Hills and beyond (now replaced by picture sandstone from Utah).  The better specimens were lavender in color and the banding often was displaced by numerous small faults.

 

Unkpapa Sandstone cropping out in Calico Canyon, Black Hills, South Dakota.  Photo courtesy, and with permission, of Geodil and Joseph Hartman P00857 (Hartman Locality L96).

 

Unkpapa Sandstone from Calico Canyon showing several microfaults. Photo courtesy, and with permission, of Geodil and Joseph Hartman P00855 (Hartman Locality L96).

I also note that my ole roommate from USD, Jim Fox, helped pen one of the definitive papers on the Unkpapa in the Black Hills.  In 1981 Szigeti and Fox assigned the Unkpapa to the Morrison Formation (Late Jurassic) as its basal member and interpreted its depositional environment as eolian (by wind). Outcrops of the Unkpapa are restricted to part of Cretaceous hogback between Sturgis, SD, and Edgemont, SD, a distance of about 100 miles. The unit conformably overlies the Sundance Formation and underlies either the main part of Morrison or the Lakota Formations, both with gradational or disconformable contacts. The Unkpapa is thickest around southern end of Black Hills, where in outcrop it ranges up to 267 ft near Hot Springs but decreases slowly northward until it pinches out near Sturgis.

 

These hand-size samples were collected in summer 1966.  The top two specimens had one side slabbed off.

Szigeti and Fox (1981), and Blakey and others (1988), believed the Unkpapa Sandstone was correlative with sandstone beds at the base of the Morrison Formation cropping out on the western flanks of the Black Hills uplift in South Dakota and eastern Wyoming. The Unkpapa dune field apparently was surrounded by lacustrine environments represented by mudstone layers in the Morrison Formation. As the region subsided, the dune field was inundated and eventually covered by lacustrine deposits.

One of my questions about the Unkpapa was answered by Szigeti and Fox:  what was the source of the sand in the unit?  They noted that as the Sundance Sea (marine, Middle to Upper Jurassic in age) withdrew from the Black Hills region, the climate became arid to semiarid. Lacustrine and fluvial depositional systems were established on low-relief topography on which sediment of the Morrison Formation was deposited. At the same time, the Sundance Sandstone in an area of northwestern Nebraska, was being eroded and fine sand was being supplied to an eolian dune field which extended northward into low relief topography. These dune sands comprise the Unkpapa Sandstone, which overlies the Sundance Formation in the southeastern part of the Black Hills area. So, the Unkpapa sandstone is reworked Sundance Formation.

The Unkpapa often attracts attention due to its color banding commonly referred to as Liesegang Bands. These Bands are colored bands of cement, often containing authigenic minerals, that are secondary structures since they cut across normal bedding.  Little is known about the mechanism creating these bands.  

In the summer of 1966, I was working for the South Dakota Geological Survey and stationed in Chamberlain, a community on the Missouri River (now the location if I-90 crossing the River).  During weekends I traveled to the plains/badlands immediately east of the southern Hills chasing “old river beds” (high level terrace gravels that had their source in the Black Hills).  I often wondered if one of these ancient (late Tertiary) streams had come through Buffalo Gap.

Truckin' on.  South Dakota plains and badlands. Summer 1966.

The community of Buffalo Gap lies on the plains just to the east of The community of Buffalo Gap lies on the plains just to the east of the Hills.   One author calls it a semi ghost town with a 100+ population.  It first came into existence during the 1875-1876 Black Hills gold rush when a stage stop along the Sidney, Nebraska to Deadwood line was created.  Ten years later the Fremont, Elkhorn, and Missouri Valley Railroad reached, and moved through, the stage stop, and a railroad station was bult and christened Buffalo Gap.  The Elkhorn, as the railroad was known, was a railroad established in 1869 running from Omaha, Nebraska, west to Chadron (the Cowboy Line) and a decade later had established a branch line from Chadron north through Buffalo Gap, Rapid City, and on to Belle Foursch at the northern end of the Hills.

At one time huge herds of buffalo (American Bison) grazed on the grasslands of western South Dakota.

The name, Buffalo Gap came from a nearby (west) water gap where a small stream (Beaver Creek) flows through a valley where the Cretaceous hogback (upturned rocks dipping east that front the Black Hills on the east side).  The Creek is an underfit stream and indicates the presence of a much larger stream in the geologic past.  Early travelers noted that buffalo (Bison) used the gap to travel back and forth to the interior of the uplands, and for shelter in the winter.  Today a gravel road traverses the gap and is a nifty drive over to the grasslands of Wind Cave National Park.

 

 A drive through Buffalo Gap will rocks from the bright red Permian-Triassic Spearfish Formation up through the Triassic, Jurassic and Cretaceous.

 At any rate, Buffalo Gap, the town, flourished in the late 1800s as a cattle shipping point for the nearby ranches.  Population jumped up to 1200 persons.  But like all good things the boom came to an end with drought, blizzards, overgrazing, dropping cattle prices, and closing railroads.  The final kill came with the Great Depression and the Dust Bowl in the 1930s.  Today the name lives on in the community, but mostly in the vast expanse of Buffalo Gap National Grassland. 

REFERENCES CITED

Access Genealogy, October 2021: https://accessgenealogy.com/north-dakota/hunkpapa-sioux-tribe.htm

Blakey, R.C., F. Peterson and G. Kocurek, 1988, Synthesis of late Paleozoic and Mesozoic eolian deposits of the Western Interior of the United States: Sedimentary Geology, 56 (1988) 3-125 3 Elsevier Science Publishers B.V., Amsterdam.

Darton, N.H., and C.C. O'Harra, 1909, Description of the Belle Fourche Quadrangle, South Dakota: U.S. Geological Survey Geologic Atlas of the United States Folio, Belle Fourche Folio, no. 164.

Szigeti, G.J., and J.E. Fox, 1981, Unkpapa Sandstone (Jurassic), Black Hills, South Dakota; an eolian facies of the Morrison Formation, in Ethridge, F.G., and Flores, R.M., eds., Recent and ancient nonmarine depositional environments; models for exploration: Society of Economic Paleontologists and Mineralogists Special Publication, Symposium, Casper, WY, June 3-7, 1979, no. 31, p. 331-349.

HAPPY NATIONAL FOSSIL DAY: OCTOBER 13

 

Having fun with fossils (Giant Short-Faced Bear femur, Arctodus compared with femur of modern Black Bear, Ursus. Collected in shoreline gravels of Pleistocene Lake Bonneville, Utah. ca. 1984. Nelson, M.E., and J.H. Madsen, Jr., A giant short-faced bear (Arctodus simus) from the Pleistocene of northern Utah: Transactions Kansas Academy Sciences, v. 86, no.1.