So, what do we do now?

    We have 2 broken pieces, a chert hammerstone, and 4,373.5 grams of debitage. The large section of the broken celt can be sawed down the middle to make two celt blanks, 16 inches(40cm) long. These would still be very large celts and longer than any of the other celts from Grossman. The smaller piece can be reworked to an axe or celt about 7 inches(18cms) long. This would more closely resemble the lower end of  the remaining Grossman celt lengths. 

Larry and others have noticed the almost total lack of axe/celt debitage on archaeological sites in his area, not only while surface hunting but also while working on professional digs. Since he has a large amount of debitage from a controlled experiment, he has decided to screen the debitage through different sizes of archaeological screens to see what evidence the archaeologist should recover from a site where axe/celts are being made. In Larry's area most archaeological screens used are 1/4" but 1/2" were used for years and Larry used window screen at Lehman-Sommers site to recovery very fine micro-drill remnants.

    The lack of axe/celt debitage leads us to assume that they are produced elsewhere and the finished product is transported to the site, used, broken and discarded (possibly reworked and/or lost), or taken along when the site is abandoned. By screening the debitage, we can bolster the assumption that axes/celts are roughed out at the quarries. It should be noted here, that a certain amount of debitage degradation should occur over time, due to the acidity of the local soils.

Stage 1

9minutes-7seconds long

    Larry screened the debitage from the separate stages through 1/2", then 1/4", and then window screen. He weighed the debitage stages separately, and recorded the weights. The first stage(9min-7sec), knapping with a quartzite hammerstone, produced 2,178.8 grams of debitage. 

Larry will divide the # of grams of debitage by the # of minutes it took to produce it. That will tell us the grams per minute (GPM) for that sample.    

Basalt caught in 1/2" screen            1,771.6 g              81%       194.68GPM

Basalt caught in 1/4" screen                  203.7g               10%         23.38GPM

Basalt  caught in window screen     142.6g                 6%        15.67GPM

Fines passing through all screens    60.9g                 3%          6.69GPM

    If axe/celt knapping occurs at village sites, it's safe to assume we would see evidence of larger pieces (over 1/2") of axe/celt material in village excavations. In this instance, if a 1/2" screen is used, 1,771.6g, or about 81% stays in the screen. Since most excavations here use 1/4" screen, it should be noted that 1,975.3g, or about 91% is caught in that screen. Window screen will catch 2,117.9g, or about 97%. We see nowhere near that much debitage on village sites.

During stage 1, we are producing basalt debitage at the rate of 233.73GPM (excluding fines).

    The next 4 stages (chert hammerstone) differ from the previous one.  Larry now has the disintegration of the chert hammer adding to the debitage. Larry weighed chert and basalt separately. The next 4 stages were randomly determined by Larry's muscle fatigue and/or updating his web site, however, they do represent different stages in the deterioration of the chert hammer.


2 hours-4minutes-53seconds long

Total time at the end of stage 2=  2hrs.-14mins.

    In the first chert hammer stage (from 9min 7sec to 2hrs-14min) the chert hammer deteriorated quickly.

Total debitage recovered in this stage 906.1g

 (GPM=grams of evidence produced per minute of work)

Basalt debitage caught in 1/2" screen  13.8 g       1.5%           0.10GPM

Chert debitage caught in 1/2" screen   220.8g       24%           1.64GPM


    Notice the amount of hammer disintegration at this point through 1/2" screen with larger pieces of chert than basalt. The total debitage in this stage is 906.1g. With 13.8 g of basalt found in the 1/2" screen, we would have recovered only about 1% of the evidence. With 220.8 g of chert, we would have found about 24% but it would have been chert debris that we would not necessarily recognize as axe manufacturing material. So, through a 1/2" screen, we would have recovered 25% of the evidence for axe manufacture and 24% of that may not be recognizable because it is chert. Only 1% would be recovered at this stage and that's not much to work with.

 So, now, we'll run it through 1/4" screen.

Basalt debitage caught in 1/4" screen  45.9g          5%            0.34GPM

Chert debitage caught in 1/4" screen    121.7 g    13.4%          0.90GPM

    If we add the 1/2" and the 1/4' together, we should see how much better we could do with 1/4" screen. With a total of 906.1 g  we add the basalt figures to get 59.7g of basalt recovered and 245.9g  of chert recovered. Note that we still have more chert than basalt. Again, the chert evidence may not be recognized, so the 1/4" screen  increased  the basalt retained, to only 6.5% of the general debitage.

Now, let's try the window screen.

Basalt in window screen                   91.2g          10%           0.68GPM

Chert in window screen                    143.2g         15.8%               6GPM

Fines basalt/chert combined             268.5g        29.6%         2.00GPM

The problem is, would we recognize the chert evidence if we saw it on an archaeological site or in the lab?

We have gone from retrieving 91% of the basalt in the 1st stage, to only 39.56% in the 2nd stage, using a 1/4" screen. Since we see very little celt debitage on village sites, it should be safe to assume that celt manufacture occurs off-site.

In stage 2, through a 1.4' screen, we have retrieved 59.7g of basalt. Divide 59.7g by150.9g and we get 39.56% basalt recovery.

In stage 2, we have produced basalt debitage at the rate of 1.12GPM. That's very different from the 233.73GPM produced in stage 1.

In stage 2, 342.5g of chert debitage was recovered in the 1/4" screen. Divide 342.5 by 485.7 (total debitage excluding fines) and we get 70.5% In other words, we would get 70.5% chert recovery in the 1/4" screen.

Basalt debitage is produced at 1.126 grams per minute.

Chert debitage is produced at 3.62 grams per minute.