Testing the Third Notch

Hi all,

 CLICK HERE TO SEE THE TEST VIDEO

The presence of a little third notch on Bonito Notched and Temporal points has interested me for a number of years.  I first saw these point types in person in 2011 while helping teach for the Archaeology Southwest Field School out in southwest New Mexico.  These points were made throughout the western half of New Mexico and into eastern AZ.  I wouldn't be surprised to see these points in northern Mexico given prehistoric interaction.  People made these points during the Late Prehistoric period, Pueblo II to III time frame, placing them around A.D. 950-1150.  Bonito points were in vogue in Chaco Canyon during the Classic Bonito phase (A.D. 1020-1120) when construction at the massive Pueblo Bonito was completed.  Check out Justice 2002:254 for info on how these relate to earlier Chaco point forms.  Bonito points were contemporaneous with non-triple notched points for some time, as both types have been found together in excavated arrow bundles at Pueblo Bonito (Judd 1954).

Temporal Point from Fornholdt Site, Mule Creek, NM

 
Temporal points occupy a more southerly region and are more or less restricted to southwest New Mexico and eastern AZ. These points also have a third notch along one margin and date to the Late prehistoric; around A.D. 900-1200 is a good ball park date range.

The points were typically made from flake blanks and often exhibit the original flake scar from core removal.  I can typically produce a point of this kind within 15 minutes.  They are thin, sharp, and a welcome asset to any quiver.

The third notch was not used as an additional element for hafting the point to a foreshaft as hafted points have been found at Pueblo Bonito with sinew wraps only around the lower two notches (Justice 2002:41; Cosgrove 1947).

So, is a third notch on one side a technological advantage, or should we look outside of technological function to explain this attribute?

Area of Fornholdt Site, NM with mule deer in distance

The Test

I wanted to see if the single third notch along one side aided in consistent and predictable fragmentation.  If the points failed to show a clear advantage over serrated points or normal point breakage patterns then we might start entertaining ideas of social, rather than technological function.  for a pilot study I created five hafted points with a single notch on one side.  These points were shot with a recurve bow into meat targets until breakage was achieved.  The broken points were observed for breakage patterning to understand technological function versus a more vaporous social marker.

Set of Bonito Notched and Temporal points ready for hafting

Hafted points with a third notch along one side

Results

All points functioned well and took several hard impacts prior to any sort of impact damage.  As always, I would want more data.  Only one point exhibited a break along the third notch.  All others broke at the tip or at the intersection of haft and point, where in my experience a majority of breakage occurs during impact.  At this point I cannot comfortably attribute the single third notch as a technological advantage over serrated points or straight-edged points.  The third notch did not make breakage patterns more predictable, nor did it make the point into some kind of frangible arrow point.

The remaining points show no strict breakage patterning

One point broke along the third notch

Temporal point going strong after several impacts

 Discussion

I can see why we would think the third notch functioned as as technological advantage.  for instance, perhaps the third notch was a quick way of making the point break apart on impact with bone, which is a good thing in some cases.  But, this was not the case.  The points broke in relatively normal order.  In fact, the points took just as much of a beating prior to breakage as any other point.  I had to shoot the points through sinew and light bone up to five times before any type of breakage occurred.  This is of course luck of the draw, as one major bone impact on the first shot would cause a break.  But, at the end of the day, shot after shot, the points did not show any superiority in breakage patterning to other points tested so far.  Perhaps in this case we have a social function or marker of time and place flaked into stone rather than strict technological choice.  More tests will help, but for now I have been persuaded to look at these types as a mark of identity, rather than technological/functional adaptation.  Possible social functions? Your guess is as good as mine.

 Happy Hunting



Refernences:

Cosgrove, Cornelius B.
    1947      Caves of the Upper Gila and Hueco Areas in New Mexico and Texas.  Papers of the peabody Museaum of American Archaeology and Ethnology, Harvard University 24(2).

Judd, Niel M.
    1954      The Material Culture of Pueblo Bonito. Smithsonian Miscellaneous Collections Vol. 124.

Justice, Noel D. Stone Age Spear and Arrow Points of the American Southwestern United States
     2002      Indiana University Press, Bloominton, Indiana.

Flake Tools and Deer Hide

Hi all,

The other day my friend Angela Gore shot an Axis deer near Fredericksburg, TX and brought the hide over to begin the fleshing and tanning process.  Angela is interested in Upper Paleolithic and Paleoindian archaeology focused on the peopling of Beringia and the Americas, specifically patterns of human dispersals, hunter-gatherer ecology, and human behavioral adaptation.

What's really cool is that she brought along a ton of raw chert local to the area where the deer was taken. This locally available raw material is commonly known as root beer chert and is a minor lithologic constituent of the larger Fredericksburg limestone, dolomite, marl, and chert group. High quality nodules from this group knap very well and offer a more durable alternative to obsidian.

Axis deer hide ready for work

Fredericksburg root beer chert nodules

 We decided to perform the task with local raw materials to see what it would have been like to process a deer hide as a Central Texas forager.  The abundant raw materials allowed us to use expedient flakes taken from a core to flesh the hide.  Informal tools are made when minor design constraints are present such that little to no reshaping of a flake is necessary to complete a task.  In an instance of raw material scarcity, our technological choice may have become centered around a more formalized flake core to preserve our stone.  In this case I created blade-like flakes (more than twice as long as wide) from a single-platform core and produced more as initial flakes became dull through use.

Flake core with parallel removal scars and partially fleshed hide

When lithic specialists think of hide processing we sometimes focus too much on formalized scrapers.  Formal scrapers are the most iconic implement, yet are only one member of a much larger tool kit.  Interestingly enough, for our task, sharp flakes comprised the entire usable assemblage for the initial stage of fleshing.  The scrapers that we tested did laughably little to separate the tough membrane from the hide.  Formal scrapers will play a dominant role in the next stage of scraping the residual tissue once the hide is salted and soaked.  Salting the hide removes fats and oils that decompose and lead to hair loss on the pelt.  In this way each step includes a dominant tool assemblage that plays a key role in the multistage process.  Overlap in tool morphology no doubt exists as trimming with sharp flakes will accompany the formal scraper use later.  As far as site formation process goes, the initial fleshing leads to the production and eventual discard of several large, sharp flakes while the ensuing hide scraping produces small retouch flakes as scrapers are resharpened.

Angela uses a sharp flake to cut flesh from the hide

Visible use wear on the fleshing flakes took the form of a dull continuous polish along the cutting margin with minor flakes removed to dull sharp areas that came in contact with hands.

This sharp curved flakes worked very well.  You can see residue along the working portion of the flake

All in all a very fun experience that reminded us both of the compound nature of tool production, use and discard during a single hide processing event.  Additionally the task helped to reinforce the usefulness of expedient flake tools and the importance of tailoring production techniques to raw material availability.

Happy Hunting!         

Oh, Snap! Obsidian Knife Breakage

Hi All,

I hafted the fluted obsidian knife from the other day and took it out for a test in the Piney Woods of Deep East TX.  I (unsurprisingly) did not manage to get a deer or wild hog this time.  I did, however happen upon a rabbit.  These rabbits have been a real hit at cookouts with the neighbors, no really.

The Test:

In keeping up with thrashing nice things, I used the hafted knife to process a rabbit in a similar method seen in the previous rabbit knife post. The materials used did not change: obsidian knife blade, antler handle and pine pitch glue.  Rather than keeping the cutting edge centered along the tool's cutting margin, this time I played with a slight bevel.  This was supposed to be used in a test of resharpening efficiency between beveled and mid-line margins.  I had misplaced my metal knife so i set out on another functional-recon experiment with what I had laying around.

Hafted knife with beveled edge created along lower cutting margin

Results:

Unfortunately, I had little chance to observe differences in beveled/centered cutting edge performance as the blade snapped during rib cage separation.  I had inverted the knife, using the curved edge in an upward direction to open the rib cage from the inside.  This task did not bode well for this specific tool.  The event was signaled by the broken blade flying across the workspace that left a spiral of blood stretched across the ground.  So...pretty cool to see actually.  Try it for yourself sometime as a party trick, no?

The catastrophe resulted in a strange hinge fracture that traveled from margin to margin and split the piece in half.  The crack initiated from the curved section of the tool as force was applied upward.  Bending stress increased upon the fulcrum created at the junction of blade and handle to a sufficient degree such that the applied stress overcame the performance capabilities of the tool.  The fact that this was a fluted knife may have something to do with the breakage, as the channel flake eliminated the typical lenticular cross-section that usually works so well under bending stress. 

Blade held as used during fracture.  Fracture initiated from top to bottom

Oblique distal view of vertical bending stress fracture

Discussion:

Is this type of breakage specific to knife use?  I have never seen a hinge fracture like this as the result of horizontal impact damage.  Perhaps this type of breakage is associated with vertical bending stress during butchering events.  More tests are needed, as usual, but his seems to be something special in the world of task-specific breakage patterns.

The following images illustrate how this piece broke.  I have found that inverting the image is a simple way to see flake scar patterns slightly better.  There are some great new imaging studies out there that are revolutionizing our ability to assess flake patterning.  Inverting the image colors on obsidian is a quick and dirty way to see a piece in another light, plus it looks cool.

Let me know if you have seen anything akin to this type of stress fracture.

Happy Hunting!  

The Cost of Education

Hi all,

Shaping stone is a timeless language, each flake a word, each tool a statement of place and time.

At some point along the line I convinced myself that learning how to remove channel flakes (fluting) was a good idea.  If I lived near a large raw material resource this would be less of an issue as I could go destroy preform after preform while gradually learning the intricate process of creating a channel for hafting with a single strike.

The concept of channel flake removal is quite brilliant and usually accompanies other techniques that require a lot of practice to master.  In brief, a channel flake is a single flake removed from the base of a biface that serves to create a long, thin area for the haft to fit.  This method allows for a relatively robust point to be hafted into a usable dart.  Without this special type of haft preparation the projectile would simply be too thick and the weight of the stone point and accompanying (gigantic) haft would render the weapon delivery system physically inept.  I'll test that situation soon.

The ability to remove single flakes from the base of a point led to some absolutely fantastic lithic traditions.  Clovis, Folsom (my personal fav) and Cumberland points all used this method to varying degrees.  But what is the learning curve like? It can't be all that easy...but is it really all that hard?  The fact that we find fluted points means it is by no means impossible, and other modern knappers do it all the time.  On the other hand, we find channel flake failures all the time too so it can't be that simple.

Folsom preform with overshot from the Lake Ilo site, North Dakota. Photo: litchiccastinglab.com

In this test I set out to see what the learning process looks like.  Do my attempts at channel flaking mirror the artifacts we find in the archaeological record?  What of my failures, do they look like unsuccessful attempts visible archaeologically?  This is just the beginning of a long-term project to document the learning process for channel flake removal.  Most folks like to show the best products of their endeavors, as if the skill set became magically integrated within one's motor skill vocabulary.  Here we enjoy the process and observe the punctuated nature of success. So, here we go.

The Test:

I decided to try a few different point types that used the method of channel flake removal.  Specifically, i thought I'd try my hand at fluting Clovis and Folsom preforms.  As part of my job is to identify and describe Paleoindian sites in New Mexico, it is to my own benefit to produce and observe the kinds of flakes produced by these early foraging communities.  I used obsidian for most bifaces as the ease of flake removal is well suited to this sort of task.  I decided to not go overboard with the channel flake removal apparatus.  Take a look around the internet and you will find some methods that work well, like giant milled metal lever devices.  while a cool modern technological innovation, metal lever devices create assurance and steal adventure, grit and risk right away.  I wanted to see if freehand percussion would work sufficiently, given practice.  The answer is yes, by the way.  There are plenty of great ways to remove channel flakes and freehand percussion is just one method.

Results:

Creating a channel flake before trimming the point to final form saves time and energy.  There seems to be no good reason to spend time making a perfectly symmetrical point, then fold it in half due to a failed flute attempt.  Once the channel flaking strategy is a success then spend time on aesthetics.

My initial attempts resulted in catastrophe.  But, in time my failure has begun to mirror problems evident in the archaeological record.  Hey, at least I am failing correctly.  There has been some success though. Several channel flakes traveled well and thinned the biface into a usable item.  The channel flaking failures, typically when attempting Folsom preforms, carried too far across the surface and removed the opposite tip.  This unfortunately reduced the final size of the item.  Reduced length means less cutting edge, less material real estate to work with and ultimately translates to less blood loss on impact.  These factors are serious attributes when attempting to kill a large angry "something" with a rock.

Lessons Learned:

Read around and you will find that creating a convex cross section is key.  To little surprise, convexity in the preform turns out to be essential.  Just like blade removal from a core (see microblade posts) flaking some convexity into the preform creates a mid line for the channel flake to follow from base to tip.  Again, unsurprisingly, platform preparation is essential.  Experience suggests uncalculated hope offers little comfort.   I am still not satisfied with my platform preparation technique.  I have seen some fantastic examples out there and my method needs refinement.  A little thing called "mapping" is helpful.  By grinding the face to be fluted with a stone one can observe the most prominent area of convexity and build a removal platform accordingly and apply force from the most appropriate direction.  Things will continue to get better from here.  I'll be excited to keep working on this technique.  There are some real masters out there, check it out on youtube if you are interested.  Oh, and hey...you don't need a fancy metal flaking leverage jig to get the job done.

 Take a look at the images below to see how things are working out.  This is the start of something fun, we'll see how my technique improves over time.

Happy Hunting.

This raw novaculite was very plastic feeling and resulted in multiple step fractures

I decided to flute this knife blade

Here is the support method that I use for direct percussion fluting

Overshot flake on Folsom preform

and yet another

This channel flake terminated early when it hit a stacked area

Overshot result on Folsom preform

Let's keep this party going! Yet another overshot

Novaculite channel flake

   

Usable Edge Loss: Obsidian Knife Performance (slightly bloody)

Unused obsidian knife

Hi all,

Images contained in this post are a little bloody. 

It's been a little while.  As it turns out, dissertation manuscripts take up a little of one's time for other things.  I've managed to slip in some time for experiments here and there though.  I was wondering the other day  about use wear patterns and usable edge loss, specifically how do different kinds of damage occur during a single activity.  Cleaning game takes more than just slicing through meat so i was interested to see how the processes stacks different types of use wear.  Questions that came to mind were things like: What types of damage occurs throughout the process and in what order might damage compile?  Does damage come in the form of dulling only, or is there actual loss of material?  The method of butchering likely predicates the variability in tool damage, and one test can't illustrate all possibilities, but I figured it would be informative to check it out.

I procured a rabbit while out in the piney woods of East Texas for some stew, a favorite winter food for me and my brother.  I processed the rabbit from start to finish with an obsidian knife.  The red and black banded obsidian comes from the Glass Buttes source complex in Oregon (Thanks Tim D and friends!).

Ribs presented no problem

Experiment:

I took total usable edge for both top and bottom cutting edges before and after to see edge loss and total damage.  I used a section of dental floss and a millimeter ruler to achieve accurate measurements along the curved blade edge.  I did not use butchering techniques that would help save the integrity of the blade.  If I wanted to keep the blade sharp for as long as possible I could choose to not use it for cuts through vertebrae or the pelvis.  When it comes down to it, all one really has to to is remove the organs which can be done with one incision.  The hide can be peeled off and requires no blade.  I chose to remove the head and cut the pelvis to thoroughly clean the critter.  I consider loss to be damage incurred such that cutting through tissue is no longer possible.

The pelvis created a decent amount of edge loss

 Results:

The total usable cutting edge breakdown:
initial top: 60mm
initial bottom: 65mm
resultant top: 5mm loss (8.33%)
resultant bottom: 42mm loss (64.61%)
TOTAL: 47mm of 125mm loss (37.6%)

Final edge form after use

 Discussion:

A quick look at the patterning in the damage illustrates that I damaged the bottom (curved section) of the blade most.  This is no surprise as I used this bottom edge for cutting through bony sections.  The top was used primarily for cutting through hide while the bottom was used for cutting the rib cage, cervical vertebrae and separating the pelvis.  Usable edge loss occurred in minor amounts with ribs, rapidly during interaction with the cervical vertebrae, and less so with the pelvis.  Edge dulling occurred rapidly upon initial hide and tissue cutting and continued gradually after the initial sharp edge was lost.  The large section of step fracture damage on the bottom blade edge came last and removed signals of earlier dulling as I removed the head and separated the pelvis. 


Conclusion:

The blade worked extremely well all said.  Different performance needs throughout the process created a compound history of edge use and damage within a single butchering event.  I was surprised at the bone cutting ability of the blade, regardless of edge damage incurred.  The blade could be used again in the current state, yet would require reliance on the top of the blade for most of the work.  While the blade worked well for all challenges presented, cutting bone, etc. a strategy of edge conservation would be a better approach.  Perhaps two tools, a sharp obsidian blade and a heavy utility edge of basalt or chert for cutting bone would combine to save the use-life of the formal tools used.

PUT YOUR EMAIL IN THE COMMENTS SECTION TO BE INCLUDED IN A DRAWING FOR THE RABBIT KNIFE !

Practicing those fun channel flakes for upcoming tests

Working on overshot thinning for upcoming tests

Happy Hunting!

Eight Years in the Making

Hi all,

Control vessel kept indoors

In carrying out the tests on this blog I can dictate some of the possibilities, sure, but overall the outcome is really about forming a deeper understanding what happened and applying new appreciations.  In an uncontrolled experiment to appreciate change in a single pottery vessel, I left a jar alone outside for the last eight years.  I like to measure the movement of charcoal, uncover, map and refit my early attempts at flintknapping, and set pottery out to die. By doing these kinds of tests I am able to see continual to change over time and observe natural forces as they reshape the contexts that supply behavioral information to archaeologists. 

 As I often come in contact with materials older than 50 generations at least, I understand that the residual of my experiments will also last much longer then my own skeleton.  About eight years ago a good friend of mine, Brad Thomson, and I spent a summer finding and using wild clay as well as firing commercial clay vessels out in the piney woods of East Texas. We had a great time that summer; I sent the biggest flake I had made to that point into my ankle bone.  Thinking back on that blood-filled boot, it wasn’t a big flake at all, and the issue was totally caused by user error.

Summer of 2005 playing with pit and kiln firing

Fall 2013. Just look at how the trees have grown!

Vertical and horizontal cracks forming in situ.

Sit tight little guy

Ceramic vessels do not break into a series of sherds that follow a normal distribution of roundness.  As shown in this test, a vessel initially breaks apart into large angular pieces.  From there, trampling by wildlife, people, movement by water and abrasion by wind move sherds towards a more rounded shape.  Also, Spalling due to fire or chemical precipitation can make sherds smaller yet still angular.

So, if one recovers an assemblage of small rounded sherds, the question must follow: were these intentionally rounded by prehistoric peoples, or are they the result of abrasion by natural processes that have also removed them from their original context.  Of course when items are out of context our job of interpreting prehistoric human behavior gets a lot harder.  See, for instance, the difference in sherd roundness between two sites that I study in Samoa.  I produced roundness measures using something called the Waddell Measure of Roundness where you divide the mean radius taken from each corner by the maximum-sized radius that can be inscribed within the sherd.  This test shows that sherds at the site of Vainu’u have seen minimal post depositional damage by water while sherds at Aoa have been significantly affected by tumbling due to water transport.  The overall significance here is that because the sherd assemblage at Aoa has become restructured by water transport, we can't really say a whole lot about pottery production over time with any confidence.  A visit to each site quickly shows differences in depositional history and erosion.  Vainu’u is flat and covered in vegetation while Aoa is on a slope and has a stream running through the area. The shapes of pottery fragments from these two sites correlate well with the visible difference in landscape topography.

 Most sherds from Aoa are rounded, while at Vainu'u they are sub angular

Intact hot rock cooking feature at Vainu'u.

This is at the base of the hill slope at Aoa

 Change over time, what a thing to watch.


Happy Hunting

GoPro Camera on an Atlatl Dart!

Click here for full screen HD!

Hi all!

A few friends and I were putting the gas station shootout test together when we decided to put a small GoPro video camera on an atlatl dart.  I'm really not sure if this kind of thing has been done before, I know I've never seen it.  We were all interested to see what the earth looked like onboard a flying dart so we taped the camera to the end of the weapon and set to work.  I'll go ahead and say it, this is awesome!  Take a look at this short clip that Danny Beard put together.  Danny Beard works in film and is a student at the University of Colorado at Boulder.

Danny Welch and Danny Beard with the apparatus. Photo: David Loome

You can see the compression and flex as the dart is launched.  This is one of the physical aspects that makes the atlatl so powerful.  As the dart is launched, the mass of the projectile point (or camera) at the front of the weapon forces the dart shaft to flex.  The flexed dart shaft springs forward during release and rockets through the air.  I attached the feather fletching in a way that made the dart spiral like a rifled bullet.  A spiral helps to maintain accuracy down range, just like any other spiraling projectile such as a football or a bullet.  You can see the spiraling really well on the footage.

This was a really fun side project. How cool is it to see the earth from a flying atlatl dart! Special thanks to Danny Beard and David Loome.

Happy Hunting.