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Don Halter
Industry Professional
Location: Bryan, TX Joined: 25 Mar 2004
Posts: 94
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Posted: Wed 30 Jun, 2004 8:08 am Post subject: axeheads in my collection |
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Here's a page I put together a while back. I actually forgot i had created it until this morning when I found it!
These are various axeheads I got from germany about 5 or six years ago. These were bought in as dug condition and are currently undergoing restoration. I was able to date one specifically using carbon dating techniques here at the university. Unfortunately, I used up a host of "favors" to get that done. I have about 30 small seax blades as well...several of which I'd really like to authenticate via dating. Anyways, here is the page with pics and such of some axe heads. Hope you enjoy!
http://www.100megsfree3.com/kragaxe/artifacts/AXES.html
Don "Krag" Halter
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Don Stanko
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Posted: Fri 02 Jul, 2004 7:12 pm Post subject: |
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Great axe heads. Out of curiosity how did you carbon date the specimen? I have a few axe heads myself but never researched any dating meathod other than shape and construction, which would work well for your scramamsax blades. I have a great book that details the different shapes of the blades throughout the centuries. Shouldn't be too hard. Give a shout if you need any help, I would love to see the blades!
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E.B. Erickson
Industry Professional
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Posted: Sat 03 Jul, 2004 2:52 pm Post subject: |
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Hi Don,
Very interesting axeheads! I also wondered how you managed to radiocarbon date an inorganic object, but your comment about dating the C in the steel answered that! I guess that there were enough pure C inclusions to allow them to extract a sample
--ElJa
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Don Halter
Industry Professional
Location: Bryan, TX Joined: 25 Mar 2004
Posts: 94
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Posted: Sat 03 Jul, 2004 5:00 pm Post subject: |
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Carbon dating is used pretty often for steel artifacts. Search under "carbon dating iron steel" and you should find several. I work at a university and knew of a few labs doing this. The more typical method required a fair amount of material to be removed. AMS(accelerator mass spectroscopy) does not. If you know anyone in a physics dept, they might have some accelartor systems that would work. You have to be careful about what type though. If any of the internal contacts/leads are carbon, you can't use it since they will contaminate the sample. You can date rocks, meteors and quite a few other things using nuclide ratios. You don't need pure carbon samples, just anything that contains the carbon. When the sample is turned into a plasma, you accelerate the nuclei and use bending magnets to make the charged nuclei "turn a corner". The difference in mass will cause them the different nuclei to have different trajectories. You end up with a graph showing different peak heights at different mass numbers. The resolution on these is pretty incredible. the peak heights are proportional to the isotopic percentage in the sample. (Yes, I used to be a lab geek.) For steel objects, you're actually dating the tree that died to make the charcoal that was used to heat the iron and make the steel. If the object had ever been reworked, your results will vary. If they are objects that have been worked with coal, your results will be bizzarre and invalid. Under perfect conditions, you can get really accurate results. I had a couple grad student friends do mine for me. They gave me a date of 1290-1350 and said they had different resuts from different areas of the blade ranging over this period. Most samples were taken from the inside of the haft-hole.
Personally, I was expecting something closer to 1475-1525 based on other small blades that were found in the same area. I will stess that this was done by grad students...so take it with a grain or two of salt, although getting a couple mass peaks is fairly straight forward on these systems. If you're interested in carbon dating techniques for artifacts I can pull some articals and send to you. If I recall, there are a few places that will do it commercially for you, but I imagine it's pretty pricey!
I tried to get some senior project together and let some students do carbon dating techniques. Naturally, I was going to volunteer about twenty small knife blades I want done . Unfortunately all the accelerators in our nuclear engineering dept use carbon-arc points for vaporizing the sample .
Don "Krag" Halter
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E.B. Erickson
Industry Professional
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Posted: Mon 05 Jul, 2004 12:48 pm Post subject: |
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Hi Don,
Thanks for the info; I learn something new every day! Don't apologize for being a lab geek- I'm a Biology teacher and can be one myself!
--ElJay
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Don Halter
Industry Professional
Location: Bryan, TX Joined: 25 Mar 2004
Posts: 94
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Posted: Mon 05 Jul, 2004 2:52 pm Post subject: |
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I'm trying to find some other labs on campus with dating abilities. Unfortunately, the other two that can do it need a considerable size sample (2+ grams), long count times and are not even close in accuracy! I wish I could track down the guy who helped me way back and find out if the systems are still here on campus. Unfortunately he's out in the research world and trying to find a Li Hong in the research community is like asking for a Bubba in East Texas! I have contacted a few friends at the nautical archaeology dept for helpful leads. they are the ones who helped me with restoration/electrolysis set-ups.
P.S. I'll be taking some detailed digital pics of all my blades and setting up a page so others can help me with IDing some of these! Eventually I want to forge out a copy of each and make a display case with the originals next to the copy. Ha! I suppose that in itself is kinda geekish in a metal-working kind of way .
Don "Krag" Halter
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