Help with C14 sample?

[BAJR]

Had this in from Beta Analytics

This seems to be charcoal but is without striations and obviously different that the other sample. A few pieces are porous (indicating either a different kind of material or different heating. )

What is charcoal without striations? would I be wrong to think it may come from metal working ?

[kevin wooldridge]

Charcoal that isn't striated? isn't that coal?

[BAJR]

That is what I am wondering, though you would think that Beta Analytics would recognise it... though ... hmmm

[Sparky]

I normally have seeds, charcoal etc identified for suitability before sending off for C14 dating. This normally sorts out the coal from the charcoal; the heart wood from the sap wood; and the seeds from the granary loaf sandwiches from those of archaeological origin...

[BAJR]

Long story attached to this shall we say the client took all the samples away with them 5 minutes after the site ended. :face-confused:

[Dinosaur]

Break in paper-trail = in the bin, in my book anyway. Could have spent the money on some of my old high-quality samples that there's no budget for :face-crying:

[Jack]

Long story attached to this shall we say the client took all the samples away with them 5 minutes after the site ended. :face-confused:

The 'client' took the samples??!! I know you can't say who the client was but that would be a break of the working methodology? If not certainly a break in EH guidelines? If it was a construction company they have no reason to do so (and probably lack the required skills or knowledge to store them or keep em uncontaminated).

As Sparky does, we also send off stuff to an environmental expert to id the samples and to advise on the suitability based on amount of earthworm and snail disturbance and possibility of the sample to be dated as being intrusive...those individual charred grains and hazel nutshell fragments get around!

Would usually agree with Dino if the samples have become 'suspect' but am guessing there is more to it.

Personally, in my experience of radiocarbon dating its not worth the money doing radiocarbon dating on an iffy sample. Even if you get a result back that 'fits' with everything else...its still a dubious date if there is a chance of residuality, intrusion or sample contamination. If you do multiple determinations and they agree you have a better case.....but the doubt still resides.
Worse still, if you get an exciting date for instance the earliest date for something, even if its correct it'll never hold water due to the doubt.
So without further info, I'm with Dino -- Bin it.

Can you give us any further details without breaking AUPs?

[Dinosaur]

As Sparky does, we also send off stuff to an environmental expert to id the samples and to advise on the suitability based on amount of earthworm and snail disturbance and possibility of the sample to be dated as being intrusive...those individual charred grains and hazel nutshell fragments get around!

But take a long, hard look at such advice before acting on it! I've got a ???just possibly neolithic building which has remained undated cos the specialist ignored all the great lumps of wood-charcoal in the hand-crafted rock-cut postholes and recommended the limited budget be instead spent on some 'short-lived' material which proved too small a sample to date even using AMS....and, err, wouldn't the original posts have pretty much filled the postholes making it a bit tricky for anything else contemporary to have fitted in?...bugger I wasn't in the office to head that one off. Individual cereal grains, or even small groups, are, from experience, to be used only as a last resort, have had some well wacky results (those darned worms!) and hazelnut shell is nigh-on indestructible and hangs around for ever. Give me articulated bone every time.

[BAJR]

The 'client' took the samples??!! I know you can't say who the client was but that would be a break of the working methodology?

Nothing more sinister than they took them to send to Beta Analytics in America - I have nae worries about that, after all they are paying for them on a project they paid for outwith development or planning.

3 samples from a ditch are better for me and will give a solid date for the site. along with the ceramic assemblage.

Not often you get a client who wants to pay for stuff without twisting arms!

I am even get slag analysis done as well.

[P Prentice]

But take a long, hard look at such advice before acting on it! I've got a ???just possibly neolithic building which has remained undated cos the specialist ignored all the great lumps of wood-charcoal in the hand-crafted rock-cut postholes and recommended the limited budget be instead spent on some 'short-lived' material which proved too small a sample to date even using AMS....and, err, wouldn't the original posts have pretty much filled the postholes making it a bit tricky for anything else contemporary to have fitted in?...bugger I wasn't in the office to head that one off. Individual cereal grains, or even small groups, are, from experience, to be used only as a last resort, have had some well wacky results (those darned worms!) and hazelnut shell is nigh-on indestructible and hangs around for ever. Give me articulated bone every time.

*!$^*!"* bollox - i actually agree with him