Alibates Agatized Dolomite - Rock Types Along the Trail

 by John Bradford Branney

 

Figure One - Artifacts from the author's collection, made from various flavors of Alibates  
agatized dolomite. Tear-drop ultrathin knife form to the right is 3.25 inches long.    

My story begins thirty-five or so miles northeast of Amarillo, Texas on what is now known as the Alibates Flint Quarries National Monument. The monument encompasses 1371 acres with over 700 visible prehistoric mining pits. For 13,000 years or more, prehistoric humans mined a special rock type that they used to make their projectile points and stone tools from the quarries. In the following paragraphs, I will delve into some of the history, prehistory, and geology surrounding a special rock type known as Alibates agatized dolomite. 

 Alibates National Monument around Lake Meredith. 
Graphic by Jason Kenworthy
(NPS Geologic Resources Division). 

Alibates agatized dolomite is a very distinctive, multicolored rock with colors ranging from maroon to red and gray to black. Mix in a little white and tan with bands of pink, blue, purple, yellow, purple, brown, and cream, and Alibates agatized dolomite exhibits a rainbow of colors (figure one).

Although Alibates agatized dolomite is the rock type’s “official” name, collectors and professionals alike refer to it by other names such as Alibates, Alibates chert, Alibates jasper, Alibates dolomite, Amarillo flint, Beef Steak Alibates, Quartermaster flint, and Alibates silicified dolomite. In this article, I will refer to the rock type as either Alibates agatized dolomite or just plain Alibates.

According to several modern-day flintknappers I spoke to, Alibates can have a resistant quality and hardness that makes it difficult to sometimes knap. As popular as Alibates was during prehistoric times, based on its wide geographical range, prehistoric flintknappers must have ignored the rock’s finicky nature and instead focused on its exotic colors and banding. I believe that Alibates probably mesmerized prehistoric humans just like it does some of us today. Alibates agatized dolomite is not only pleasing to the eye, but perhaps prehistoric humans believed the rock enhanced their hunting success. 

     Figure Two - Boulders of white Alibates Dolomite cascading

down hills at Alibates Flint Quarries NM. NPS Photograph. 

                                                                                                                 

How did the name Alibates agatized dolomite come about? Gould (1907) first described the agatized dolomite a mile and a half south of the national monument along Alibates Creek in Potter County, Texas. A local rancher named the creek after his cowboy son, Allen “Allie” Bates, and Gould named the rock type after the creek where he found it. Agatized is an adjective describing the geological process that creates the rock type called agate, which is a striped or banded, sometimes translucent, cryptocrystalline variety of quartz. And the last word in the rock type’s description, dolomite, is a common, rock-forming mineral that I will discuss later in the article. 

Meltzer (2006:250) added some flavor to the origin of the name Alibates agatized dolomite by relaying the following story. In 1926, excavations began at the original Folsom site in New Mexico. In 1928, the American Museum of Natural History joined the Folsom excavation with vertebrate paleontologist Barnum Brown in charge. In November of 1930, Oklahoma State Geologist Charles Gould sent Barnum Brown a package of Alibates agatized dolomite. Gould acquired his experience in Texas Panhandle geology several decades prior to 1930. Gould also happened to be the first person to map and describe the Alibates Dolomite Formation where the agatized dolomite came from. 

Figure Three - The Drake Clovis Cache. One of the 
most famous examples of mostly Alibates artifacts
found on the high plains of northern Colorado. 

Barnum Brown did not agree that the rock samples Gould sent him were agatized dolomite. Brown believed the rock samples were jasper, a variety of chert containing iron-oxide impurities which gave the rock type a wide range of colors, especially red. Being an experienced geologist, Gould knew exactly where the rock samples came from. He replied to Brown that the rock samples “formed a constituent part of a ledge of dolomite that outcropped over parts of the Panhandle of Texas”. Gould added that the best site for finding Alibates agatized dolomite was “on the bluffs overlooking the south Canadian River”.

Barnum Brown and Charles Gould probably agreed to disagree on the rock type, but Brown and his associates confirmed that Paleoindians used Alibates agatized dolomite to make projectile points and stone tools at the Folsom site in New Mexico. Long and short of it, the label Alibates agatized dolomite prevails even today.  

The dolomite “on the bluffs overlooking the south Canadian River” that Charles Gould referred to was a fifteen-foot-thick bed of agatized or silicified dolomite and mudstone that geologists call the Alibates Dolomite Formation or the Alibates Dolomite for short. That formation contains three informal members: a lower gray dolomite which is resistant enough to form ledges, an upper brecciated and fractured upper gray dolomite that supplied most of the agatized dolomite, and a red to brown calcareous mudstone sandwiched in between the two dolomites. The Alibates Dolomite Formation lies above the red beds of the Permian Whitehorse Formation and lies below the red beds of the Permian Quartermaster Formation. Geologists often refer to that entire sequence of rocks as the Permian Red Beds. The twelve-million-year-old Ogallala formation from the Miocene-Pliocene Epochs lies directly on top of the two-hundred-sixty-million-year-old Permian Red Beds in what geologists call the Great Unconformity, a massive gap in the geologic record.    

It is now time for us to board our time machine for a little geology lesson. I am setting the dial of our machine for around two hundred fifty-five million years ago during the Permian Period. At that time, North America, and most of the rest of the world were not geographically located where they are today. Texas was situated along the equator and was a small part of a supercontinent named Pangea. During that time period, Texas landscapes were a combination of coastal plains, marine basins, and tidal flats. The Permian Red Beds for the most part were terrestrial deposits and formed alongside a great ocean that extended up from the south.

Figure Four - Pangea in Late Permian. Texas and the Alibates National Monument are
 located near the Equator at the southwestern end of the Central Pangean Mountains.     

Throughout geologic time, climate change has been a big factor in determining both weather and landscape, and the Late Permian in Texas was no different. When colder global climates occurred, thick ice caps grew in the north and south parts of Pangea. To grow, the ice caps borrowed water from the oceans which resulted in lower sea levels and more landmass. During that time in Texas, river and stream systems deposited hundreds of feet of relatively soft shale, sandstone, and mudstone, including where the Alibates National Monument lies today.   

When the climate reversed and warmed up, the ice caps melted, and the water returned to the seas. Sea levels rose and inundated the land with seawater, stretching from the Arctic Ocean near Alaska on the north, through Canada and the United States, and connecting with the Pacific Ocean in Mexico. When sea levels dropped again, lower-lying basins trapped the seawater, and when that water evaporated, it left behind organic matter and salt. That was how thin beds of gypsum formed in the national monument area and the main reason why the Canadian River tastes salty even today. And how was the Alibates Dolomite Formation created?      

Dolomite is a common rock-forming mineral and in its pure state, it is white to light-colored. Chemists specify dolomite as CaMg(CO₃)₂. Jackson (1970:176-178) and Scholle et al. (1983:194-195) studied the modern-day creation of dolomite deposits and reported that the formation of dolomite occurs along the ocean in hot, dry climates, a few inches above high tide in a zone referred to as the supratidal, or the splash or spray zone. The scientists proposed that dolomite started out as calcium carbonate (CaCO₃) in the form of calcite and aragonite sediments, mostly consisting of the remains of plankton, coral, algae, and shelled animals. Seawater soaked the supratidal zone during storm surges and abnormally high tides. Seawater also saturated the supratidal zone from underneath as capillary action pulled seawater to the surface of the zone (figure five). When the seawater evaporated, it left behind magnesium-rich brines which chemically reacted with calcium carbonate to form dolomite. 

Figure Five - Schematic diagram showing sedimentary environments from continental 
to marine, their relationships to sea level, and the relative amounts
of capillary action (Scholl et al. 1983:172). 

For agatization or silicification to occur, silicon dioxide must replace the original dolomite. Bowers and Reaser (1996) reported that at the Alibates National Monument, a silica-based mineral called chert completely replaced the dolomite in the upper dolomite member while only partially replacing the dolomite in the lower member. That led the investigators to conclude that the agatization or silicification process occurred from the top down with the upper dolomite member acting as the main host rock for silica solutions. Bowers (1975) stated that minor amounts of aluminum, iron, and manganese were deposited with the silica in the dolomite and those minerals account for the beautiful bands and colors found in Alibates agatized dolomite.              

Where did the silica come from that agatized or silicified the dolomite? Since the overlying rocks above the Permian Red Beds were eroded away, scientists can only speculate as to the source of the silica. The U.S. National Park Service (2022) provided three theories for the origins of the silica in the dolomite. The first theory entails an eruption of a Yellowstone super-volcano around 675,000 years ago provided silica via volcanic ash. Around Lake Meredith, there are several locations where there is a three-foot thick bed of Yellowstone ash. The theory goes that when it rained, some of the silica-rich ash dissolved into the rainwater and percolated down through the dolomite. Another theory is that the deposition of the Ogallala Formation sediments brought silica-rich material with it. The third theory, the National Park Service proposed was that silicification occurred at the same time as the dolomite formed, but for that to occur, perfect conditions were in order.  

We may never know for sure but what we do know for sure is that Alibates agatized dolomite is a beautiful and desirable rock type for artifacts!         

Bowers, R. L., 1975. Petrography and petrogenesis of the Alibates dolomite and chert (Permian), northern Panhandle of Texas [M.S. thesis]. The University of Texas at Arlington, Arlington, Texas, 155 pp.

Bowers, R. L., and Donald F. Reaser, 1996. “Replacement Chert in the Alibates Dolomite (Permian) of the Texas Panhandle”. The Texas Journal of Science.    

Gould, C. N., 1907, “Geology and water resources of the western portion of the Panhandle of Texas”. U.S. Geological Survey Water Supply Paper 191, pp. 1-70.

Jackson, Kern C., 1970, Textbook of Lithology, pp. 176-178. McGraw-Hill Book Company. New York.

Meltzer, David J., 2006, Folsom: New Archaeological Investigations of a Classic Paleoindian Bison Kill. University of California Press. Berkeley.  

Scholl, Peter A. Don G. Bebout, and Clyde H. Moore, Carbonate Depositional Environments, AAPG Memoir 33, pp. 194-195. The American Association of Petroleum Geologists. Tulsa.

U.S. National Park Service, 2022, Geology-Alibates Flint Quarries National Monument (nps.gov).

The historical fiction novels written by John Bradford Branney are known for their impeccable research and biting realism. In his latest blockbuster novel Beyond the Campfire, Branney catapults his readers back into Prehistoric America where they reunite with some familiar faces from Branney’s best-selling prehistoric adventure series the Shadows on the Trail Pentalogy.

John Bradford Branney holds a geology degree from the University of Wyoming and an MBA from the University of Colorado. John lives in the Colorado mountains with his wife, Theresa. Beyond the Campfire is the eleventh published book by Branney.         

Folsom v. Clovis Technology - SHADOWS ON THE TRAIL



Figure One - Wide range of High Plains Folsom Points from Texas, Colorado, Wyoming, and South Dakota. The longest point is 1.9 inches long. John Bradford Branney Collection.  

Did you identify the above projectile points as Folsom?  

My five-book adventure series about North America and Paleoindians titled the SHADOWS on the TRAIL Pentalogy began in what is called Texas and Colorado today. Ultimately, the latest book in the series, BEYOND the CAMPFIRE, ended up in the Black Hill of South Dakota and Wyoming. 

The books were written about a mysterious group of people we now call Folsom who lived on the Great Plains around twelve thousand six hundred or so years ago. There is no archaeological evidence that the Folsom Paleoindians used any kind of written language. Hence, they probably handed down their customs, processes, rituals, and folklore from generation to generation through word of mouth. One of the distinguishing characteristics of the Folsom Paleoindian culture was a beautifully-crafted fluted projectile point that is arguably the finest projectile point type ever made in North America. One of the processes that the Folsom People passed on from generation to generation was the making of these fabulous fluted projectile points. Figure one is a photo of a few examples of Folsom points from my personal collection. Even with the variation in shape, size, material, and quality, most people familiar with artifacts would identify them as Folsom projectile points. 



Figure Two - The third book in the SHADOWS on the TRAIL Pentalogy.
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In the third book of the SHADOWS on the TRAIL Pentalogy titled WINDS of EDEN, I wrote about how I thought the Folsom People passed along their flint knapping processes  In the passage below, a tribal elder teaches children how to make these wonderful fluted projectile points. School is now in session!

The old man picked up a square of tatanka – bison hide. He placed it on top of his left thigh. He then picked up the flat rock and placed it on top of the bison hide. He then placed another square of bison hide over the top of the flat rock. The old man picked up an unfinished spear point and the antler punch. The three boys watched, never taking their eyes off the old man’s skilled hands. The old man then adjusted the flat rock so it was on the inside of his left thigh. He pushed the tip of the unfinished spear point against the flat rock and lined up the antler punch against the tiny knob on the base of the spear point. When the old man was satisfied with the positioning of the spear point, he placed the other end of the antler punch against his right thigh.

Since the elder was teaching the children a relatively complex process (rarely duplicated with success even today), we would expect to find errors and variations in the children's final product. Twelve thousand years later, you or I might find one of the children's Folsom points and wonder why all Folsom points weren't created equal. In general, Folsom projectile points exhibit three critical characteristics; 1). fluting, 2). thinness, and 3). micro pressure retouch along the edges. You can see these characteristics in all of the Folsom points in figure one. 

Figure Three - More Folsom points from my collection. 

I am switching gears now, to an earlier group of Paleoindians before Folsom. These Paleoindians were associated with what we call the Clovis Complex.

Ever since the discovery of the famous Folsom, Clovis, and Plainview sites in the early part of the twentieth century, there has been an ongoing effort to identify and categorize all Paleoindian projectile points into specific projectile point type buckets. Before the discovery of the above sites, archaeologists and collectors lumped most finely-made western Paleoindian projectile points into a broad category called Yuma, named after the town in Colorado where collectors were finding these artifacts in sand blowouts during the Dust Bowl years of the 1930s. 

One Paleoindian projectile point type with a broad geographical range in North America was named Clovis after the insitu discovery near the town by the same name in New Mexico. Today, collectors and archaeologists find Clovis-styled points in forty-eight states, Canada, and Mexico. Clovis projectile points are normally fluted, just like Folsom, but the flutes on Clovis are shorter and angled outward from the base (see figure four which demonstrates typical fluting angle differences - "a" in the diagram is Folsom and "b" is Clovis). In addition, Clovis projectile points exhibit less intricate pressure flaking and retouch than the average Folsom projectile point. Just like Folsom, Clovis projectile points show a broad range in dimensions, form, and material.

Figure Four - One way to differentiate 

between Folsom and Clovis. Folsom fluting 

is parallel to the biface plane (flat) while 

Clovis is diagonal to the biface plan (angled). 

Credit unknown.    

There are several plausible explanations for the variation in Clovis projectile points. First of all, Clovis flint knappers did not work from blueprints like modern-day manufacturing workers do. Clovis projectile points did not have written specifications, and all Clovis flint knappers were not created equal. For that matter, no Paleoindian flint knapper had exactly the same skills and experience as their peers! People with different levels of skill, experience, and creativity created Clovis projectile points! Last but not least, Clovis and other Paleoindian flint knappers dealt with a wide range of raw materials with different mechanical properties and quality. For example, chalcedony knaps differently than silicified sandstone which knaps differently than obsidian. Some raw material was just better for flint knapping than other materials, resulting in a wide range of quality and form between different projectile points. 

We can and should expect variation in quality, dimensions, and sizes for Clovis and Folsom projectile points!

  

We see variations in Clovis-styled fluted projectile points across the different regions in North America. The variation in size, shape, manufacturing process and material has led to many debates about whether or not these regional variants of Clovis-styled fluted projectile are actually Clovis points and fit under the umbrella of the Clovis Paleoindian culture that swept across North America. Some analysts argue that these regional Clovis-styled fluted projectile points prove by their chronological and morphological differences that they did not come from a single Clovis culture while others argue that these Clovis-styled fluted projectile points are just regional variations of a common Clovis theme at a slightly different time and place.

If these Clovis-styled fluted projectile points did come from one common Clovis culture, the variation might be explained by a process called 'drift". Drift occurs when we see the changing of a standard through time within groups of people who share the same cultural ancestry. Drift can occur in any given culture and can happen for a variety of reasons such as isolation of a population or innovation within a specific population or the evolving needs in a changing environment. As an example of the last item; when mammoths and mastodons became scarce or were absent, Clovis people might have adapted their weaponry to hunt different animals. We should expect a change in their projectile point style going from hunting mammoths as a mainstay to hunting bison or smaller mammals. In figure five below I show three different Clovis-styled variants from the eastern United States. Did these precede or follow Clovis? These three eastern types carry a bunch of Clovis characteristics. 

Figure Five - Clovis-style regional variants from eastern U.S. (Haynes 2002) Were these made by the same Clovis culture discovered in the west or different cultures that copied the fluting technology?   

Figure six represents a few Clovis projectile points from my high plains Clovis collection. You can see by the photo that even though these Clovis points were surface finds from the same region, they have quite a bit of variation. Even with the differences in form, fluting length, and flaking patterns, they are still Clovis points. In the caption below figure six, I identified the variants from other regions of North America that my high plains points resemble. As an example, the first point in my photograph is a Clovis projectile point that was surface found in northern New Mexico. It resembles the Gainey projectile point from the Great Lakes region in figure five. 

The photo in figure seven shows Clovis-styled fluted projectile points from the east coast of the United States and Canada. These Clovis-styled fluted projectile points are not typed as Clovis, even though they have similar characteristics to my Colorado Clovis point in figure six, second from the right.   

Figure Six - High Plains Clovis points demonstrate the wide range of variability. From left to right; New Mexico Clovis, Gainey variety; Nebraska Clovis, Colby variety, Montana Clovis, western variety; Colorado Clovis, Hazel Variety, Colorado Clovis, eastern variety; Colorado Clovis, Barnes Variety. The longest point is 3.8 inches long.
John Bradford Branney Collection.       

The bottom line is that there are a variety of reasons that a single point type such as Clovis shows variation between different projectile points within the type. That does not mean that these regional variants were not part of the Clovis Paleoindian culture that overtook North America for a few hundred years around 13,000 years ago.  

Figure Seven - Clovis-style points from Nova Scotia, New York, and Main.
(Haynes 2002) Boy, they sure look like my Colorado Clovis
above (fifth point).   

I am going to say goodbye for now and return to WINDS OF EDEN to see what happened between the elder and the children. School is back in session.      

The old man motioned for his two young grandchildren to sit down in front of him, close enough to see, but far enough away to avoid flying pieces of sharp rock. The old man readjusted the flat rock with the tip of the spear point. He then carefully positioned the groove in the antler punch with the tiny knob at the base of the spear point. When everything was to his liking, the old man picked up the heavy antler hammer and took a couple of practice swings in the air. The old man then held the antler hammer above the antler punch and swung down with enough force to transfer energy from the antler punch through the rock. The rock popped loudly and when the old man lifted up the spear point for the children to see, a flute or groove ran longitudinally up the entire length of the spear point. The children laughed as if it they had just witnessed great magic. Their eyes were as big as the moon as they looked around at each other. The old man gazed around at the children, smiling. The old man was proud of the flute in the spear point and relieved that he could still do it. However, what made him the happiest was passing down the fluting tradition to the next generation of the tribe.

2002    Haynes, Gary. The Early Settlement of North America - The Clovis Era. University             Press. Cambridge.  

The historical fiction novels written by John Bradford Branney are known for their impeccable research and biting realism. In his latest blockbuster novel BEYOND the CAMPFIRE  Branney places his readers smack dab into the middle of the late Pleistocene along the high plains of North America. BEYOND the CAMPFIRE is Branney's eleventh book.  

John Bradford Branney holds a geology degree from the University of Wyoming and an MBA from the University of Colorado.

 

Angostura V. Agate Basin along the SHADOWS ON THE TRAIL

Figure One - 3-inch-long Angostura spear/knife form surface recovered on private
land in Goshen County, Wyoming. Note the oblique parallel flaking. 
John Bradford Branney Collection.

For those of you who have read my prehistoric book series, the SHADOWS ON THE TRAIL Hexalogy, you already know that the books are about the Folsom prehistoric culture, populated by those mystical Paleoindians who lived on the Great Plains around twelve thousand seven hundred years ago. I have written several blog and magazine articles about the Folsom prehistoric culture and its artifacts, and the Paleoindians who came before and after the Folsom prehistoric culture. The style of the projectile points may have changed through prehistory, but the lifestyle and subsistence patterns did not change much for several thousand years.

Figure Two - the first book in the SHADOWS on the TRAIL Hexalogy
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This article is about one of the prehistoric cultures that came after the Folsom culture and the time period I chose for my book series, the SHADOWS ON THE TRAIL Hexalogy. Archaeologists call the projectile points from this prehistoric culture Angostura.

Figure Three - 2.1-inch-long Angostura made from moss agate 
and surface found in southern Colorado by R.D. Mutz 
in the 20th century. John Bradford Branney Collection.   

One of the non-perishable items that archaeologists use to identify a specific prehistoric culture is the style and technology of stone projectile points. In many cases, some bone, fossilized or otherwise, stone tools, and projectile points are the only items surviving in a Paleoindian archaeological site to help identify the prehistoric culture. Archaeologists lean heavily on projectile point types as cultural identifiers. Surface artifact hunters like me use defined projectile point types to determine the projectile point types we find on the surface of the ground. We use projectile point types to identify the presence or absence of specific prehistoric cultures where we hunt for artifacts. 

In 1946, archaeological investigators working on the Missouri Basin Project were inventorying archaeological sites along the upper Cheyenne River on the southern flank of the Black Hills in South Dakota. Plans for a future reservoir were threatening several archaeological sites, and the investigators were doing salvage work before the reservoir water engulfed the sites. 

By 1948, archaeological investigators were focused on the Ray Long Site, an early human site in a small arroyo along Horsehead Creek. The archaeologists discovered several fire hearths and camp-related stone tools between five and seven feet deep in the soil. Associated with that prehistoric campsite, investigators discovered what seemed to be a new projectile point type. At the time, the Ray Long Site was important for another reason; the investigators found evidence of plant gathering and processing in a 9,000-year-old site. 

Figure Four - 5.6-inch-long Angostura spear point made from obsidian
and surface recovered on private land in Hyde County, South Dakota.
Note the similarities to an Agate Basin point type. 
John Bradford Branney Collection.  

Archaeologist J.T. Hughes proposed the name "Long points" for the newly discovered lanceolate-shaped projectile points found at the Ray Long site in honor of the landowner. Hughes' intentions were good, but can you imagine how confusing it would be for a projectile point type to have a descriptive name such as long, short, fat, wide, red, green, or narrow? By 1954, archaeologist Richard P. Wheeler eliminated the confusion by renaming Long points to Angostura points, after the nearby reservoir. It was somewhat ironic that the word angostura in Spanish means "narrowness". To add more confusion, it took Wheeler almost forty years to publish the formal description for the Angostura projectile point type!   

 

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Angostura points were described as medium to large lanceolate-shaped points with random to parallel-oblique flaking. The blade edges were straight to slightly convex. The stem on the points contracted, sometimes quite dramatically. Basal thinning was accomplished by short pressure flakes, creating slightly concave bases. Oftentimes, Angostura points exhibited oblique parallel flaking and continued the Paleoindian/Early Archaic tradition of polishing or grinding the basal edges where the projectile point was hafted. 

Figure Six - Angostura points from private land in Colorado, Wyoming, 
and Nebraska. Note the oblique flaking on most. The longest
point is 4 inches long. John Bradford Branney Collection.

The Angostura point type chronologically and morphologically overlaps with three other projectile point types on the High Plains: Frederick, Lusk, and Jimmy Allen. Some scholars have proposed lumping all four of these types into a single category called oblique-flaked Plano points, foregoing the use of specific point type names (Cassells 1986). Other scientists have proposed lumping these four projectile point types in what they called the Frontier Complex (Kornfeld et.al. 2010). A few scholars believe that the Angostura point type was not necessary at all because it fitted neatly within the Agate Basin projectile point type (Wood 1998). I am in the latter camp. 

Figure Seven - Agate Basin projectile points and knife forms as a comparison with the
Angostura points in figure six. The longest point is 4.6 inches long.
John Bradford Branney Collection. 

After studying many projectile points, especially those found at the Agate Basin type site in eastern Wyoming, it is my opinion that Angostura technology is a variation of Agate Basin technology with geographical and temporal overlap. More than a few of the Agate Basin points found at the Agate Basin type site have an uncanny resemblance to Angostura points.

Figure Seven - Central Texas Angostura points, 

2.5-inch-long dart/knife forms. 

John Bradford Branney Collection.  

When it comes to projectile point typology, there are two "camps". There are those people who are "lumpers", and there are those people who are "splitters". "Lumpers" try to fit as many projectile points as possible into existing projectile point types, using a philosophy that there are variations within each projectile point type. You might say that "lumpers" slice their bread a little thicker. In contrast, "splitters", see variation in a projectile point's characteristic and form as a possible reason for defining a new projectile point type. You might say that "splitters" slice their bread a little thinner.

I happen to be a member of the "lumper" camp, and I do not believe that Agate Basin and Angostura require separate projectile point type designations. I see both types as a variation around a common theme, and that they are pretty much the same projectile point type, with Agate Basin being the first expression of that theme. 

What do you think?  

References Cited

Cassells, E. Steve
1986  Prehistoric Hunters of the Black Hills. Pages 38-39.     

Kornfeld, Marcel, George C. Frison, and Mary Lou Larson
2010  Prehistoric Hunter-Gatherers of the High Plains and Rockies. Page 495.     

Wood, W. Raymond
1998  Archaeology of the Great Plains. Page 114.

The historical fiction novels written by John Bradford Branney are known for their impeccable research and biting realism. In his latest blockbuster historical fiction novel titled CROWN of LIGHT, Branney catapults his readers back into Prehistoric America, where they reunite with some familiar faces from Branney’s best-selling prehistoric adventure series, the SHADOWS on the TRAIL Hexalogy.

John Bradford Branney holds a geology degree from the University of Wyoming and an MBA from the University of Colorado. John lives in the Colorado mountains with his wife, Theresa. CROWN of LIGHT is the twelfth book published by Branney.

Prehistoric Burins and the SHADOWS on the TRAIL Pentalogy

Figure One. Scottsbluff knife form from Wilson County, Texas. The most interesting feature 
of this, 10,000 years plus beauty, is its burinated tip.
John Bradford Branney Collection.  

A prehistoric burin is a specialized, chisel-like stone tool created by driving a flake or flakes off the edge of another flake, biface, or blade to produce a ninety-degree edge for working hard substances such as ivory, antler, and bone. The sharp corners created by the burin were so useful that prehistoric knappers deliberately made them. The removed edge fragment is called a burin spall.

In the knapping process called burination, a small, relatively thick flake is removed from a flake, blade, or biface using a snapped termination or previous burination scar as the knapping platform. Burination can also be used to remove a sharp edge for the safe handholding of a knife form. Burination was extremely common in the “Old World” Paleolithic of Europe, Siberia, and Beringia. Paleoindians in North America also made and used burins. For some reason, it appears that the Clovis culture only used burination in rare instances, but it became quite popular during Folsom and Cody Complex times. Most of my stone tools with burins came from my Folsom and Cody Complex sites.

Figure Two. Burin tip (B) of the Scottsbluff knife form
photographed in figure one. The 'stop notch' (N) ensured
that the burin flake did not travel too far down the edge of
the biface or into the body of the biface. 

Figure one is a photograph of a 3.7 inch long Scottsbluff knife form, made from Edwards Chert and found on private land in Wilson County, Texas. This artifact is Early Archaic with an approximate age of 10,000 years. The knife form had two or three resharpenings that have reduced its overall length, but the most interesting feature of this Scottsbluff knife form is its tip (figure two). The tip of the knife form at some time was pressure flaked into a burin tip (an engraver) and was re-tipped two more times. Burination strengthened the tip of the Scottsbluff knife form exponentially, keeping the edge from crushing and failing while engraving hard objects.

Most burins and burin spalls are unspectacular features. Most people do not even recognize them. Caution has to be applied when differentiating an impact fracture from a burin. Not every missing sliver off an artifact is a burin! Finding impact fractures on an artifact is far more common. Usually, after I post artifacts with burins, I receive a rush of requests to look at people's artifacts who think they might have burins. Identifying burins from photographs is difficult at best. It is best to have the artifact in hand so that you can feel the edges for use wear and examine the artifact. All of my artifacts that I claim to have burins have gone through thorough examination and scrutiny.       

Figure Three. My heart was pounding!

Figure three is an in situ photograph of a Scottsbluff (Cody Complex) point half-buried in the sandy creek bottom at my SHADOWS on the TRAIL site in northern Colorado. The day was August 23, 2008, when I spotted this Scottsbluff point lying in the sand. It took my breath away and my heart pitter-pattered. It was obvious what it was, but the tip was buried. The square base and the flaking pattern were definitely Cody Complex. After a somewhat extended photoshoot, I pulled the Scottsbluff point out of its sandy grave. My heart sank when I saw that an impact fracture had taken off the tip of the point.   

Figure Four. Scottsbluff point with a blunted tip.  

I yelled out the PG-13 version of "DRAT!". Quite frankly, even though I had found a tremendous artifact I was disappointed because of the broken tip. My first reaction was that this beautiful 2.8 inch-long Scottsbluff point ended its useful life by hitting bone or rock and fracturing its tip. I pocketed my find and went back to hunting for the rest of the day. It wasn't until I got home later that night and had a chance to study the point that I realized that the original Scottsbluff point was probably decommissioned because of an impact fracture and the creative Cody Complex knapper recommissioned the point into a stone tool by intentionally creating a double-sided burin for use in scraping wood and hides (figure five).

Figure Five. Twin burin edges with a chisel tip. 

My interpretation of the history of this Scottsbluff point goes something like this; The maker of this Scottsbluff point used a dendritic jasper as the raw material. The dendritic jasper looks like some of what I find on the Hartville Uplift of Wyoming. The finished projectile point at some stage suffered damage to its tip. Instead of repairing the projectile point, the Cody Complex knapper refurbished the broken point into a knife form with double burins. He or she removed burin spalls on both sides of the impact fracture (figures five and six). Then the innovative knapper created a chisel-like edge on the rounded tip. He or she could have used this Scottsbluff knife form as a burin, knife, scraper, and chisel for use on meat, bone, wood, and hides.

Figure Six. Chisel tip is well polished.  

The raw material at the tip of this Scottsbluff knife form has a different color and texture than the rest of the artifact. I attribute this to polish or use-wear from the way its owner used it.  There is evidence that the  owner might have re-tipped or repaired the chisel and burins once or twice since that area of the knife form has a different flaking pattern than the rest of the biface.          

Another important feature about burins when found in Paleoindian contexts, they seldom show use wear on the edge near where the burin spall detached in front of the striking platform. Instead, use-wear is usually found on the edge adjacent to the striking platform or tip. In the case of this last Scottsbluff point, the most use wear was at or near the tip.

So, there you have it. A couple of Cody Complex burin examples. You will have to read the SHADOWS ON THE TRAIL Pentalogy to see how the Folsom Complex used burins. All the information needed to order your copies of my book series is below. 

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