Main Discussion Area > Flintknapping
1971: "Investigations concerning the thermal alteration of silica minerals"
mullet:
Ocala Chert and Brooksville Chert will heat treat around 450-500dgs. Quiet a few chert points found down here have been heat treated. Most high quality Marion, Newnan and Hillsborough's that are real thin have been heat treated.
AncientTech:
On Clovis thermal alteration, at the Ready Site
http://www.clt.astate.edu/jmorrow/clovis.pdf
Morrow:
"Due to the proximity of the Ready site to residual or lag deposits of high- quality Burlington chert, it is not surprising that this material dominates the entire site assemblage. Considering only the fluted points and preforms from the site, some 86.5 percent are made of Burlington chert. An occasional fluted biface in the collection will exhibit traces of incidental (unintentional) exposure to heat but NOT ONE OF THESE ARTIFACTS APPEARS TO HAVE BEEN INTENTIONALLY HEAT TREATED. Judging from the large numbers of unfluted, but potentially Early Paleoindian stage 2 and 3 bifaces recovered from the site, all stages of point production are well represented in this local RAW MATERIAL."
A total of 694 artifacts were collected at the Ready Site, and preserved in six collections. This includes HUNDREDS of Paleoindian artifacts (PAGE 3). This also includes 224 fluted biface rejects (PAGE 4). Approximately 86.5% of the fluted bifaces, and preforms, were made from local Burlington chert (PAGE 4). What is the incidence of intentional thermal alteration of the Burlinton material? Apparently, the incidence of intentional thermal alteration is 0%, in spite of the fact that there are HUNDREDS of Burlington bifaces, and preforms (PAGE 4).
MODERN KNAPPER'S EMPLOYMENT OF THERMAL ALTERATION VERSUS CLOVIS PEOPLE:
Burlington 600-650 DEGREES - On the following materials, dry out at 200° for 8 hours,then ramp up 50° per hour temp indicated. HOLD FOR 8 HOURS. Ramp back down at 30-50° per hour.
http://orerockon.com/Heat_treating.htm
Burlington Chert - 650-675 DEGREES - HOLD MAXIMUM TEMPERATURE FOR 72 HOURS.
http://www.pugetsoundknappers.com/how_to/Heat%20Treating%20Guide%20with%20Table.html
CLOVIS PEOPLES - NO THERMAL ALTERATION OF BURLINGTON CHERT.
So, why would Clovis people not employ thermal alteration at all, while working materials such as raw Burlington chert, even while they occasionally used thermal on other materials such as hard jaspers, and possibly even agatized coral?
It is my opinion that there are at least three possible answers to this question:
A. The Clovis knappers were employing flaking processes that generated much greater power than can be generated via hand-swung batons. Thus, making the stone any weaker simply was not necessary.
B. The Clovis knappers employed thermal alteration primarily as a means of altering grain, while conserving tensile strength as much as possible. As a result, some types of naturally blocky materials, would have become more easy to work, possibly with the conservative employment thermal alteration. In essence, the focus would be to improve grain, but not necessarily overly weaken inherent tensile strength.
C. Possibly, both ideas - A and B - could have been involved in the choices once made by the Clovis knappers.
Here is an example of a high power flaking operation, involving a common deer tine, and raw Colha chert, that other knappers may cook for up to fifteen hours, in a commercial kiln - this experimental example is raw. Perhaps the Clovis knappers used some similar process:
(Disclaimer: These photos are not intended to represent a "how to" tutorial on flaking. They are simply intended to illustrate the effects of high powered flaking processes, on raw materials, similar to what can be noted in the archaeological record.)
AncientTech:
--- Quote from: caveman2533 on June 21, 2015, 09:32:36 pm ---It tells me if they were heating their stone that they had not discovered your mysterious process.
--- End quote ---
So, do you think that the stone tool needs of Paleoindian era big game butcherers was the same as the stone tool needs of archaic era small game hunters? If not, then of the two parties which party would have needed high tensile strength edges, that did not quickly wear out?
mullet:
I've watched Claude Van Order percussion reduce/ flake, raw coral and Florida cherts using copper boppers, antler billets and hammer stones. He consistently reduces these hard rocks using these different tools. But he prefers copper. I have a Clovis made from Argilite that he freehand fluted with a copper billet while talking to a group of people just to show it could be done with copper.
Dalton Knapper:
Jeff Gatwood in NE Arkansas makes excellent Clovis and Dalton points from unaltered Lafayette Formation (Crowley's Ridge) materials and that stuff is hard as the dickens. Julie Morrow (the author referenced a couple of posts up, and station archeologist at ASU in Jonesboro, AR) has even made comments to me about Jeff's ability to tackle the raw material. I am pretty sure Jeff uses billets and likely copper.
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