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Re: orion: Castor oil impact on C14 tests
On Sun, 26 Oct 1997 23:52:07 GMT +100, GD@teol.ku.dk writes:
>Asia Lerner's post with analysis of outliers is well-reasoned
[... snip ... already seen ...]
>I have come up with one method--see what you think of this. If the
>occasional scrolls 14C date that is "later" than most is really an outlier, it
>ought to be nonrepeateable, and disappear into the aggregate on a
>second or third measurement.
This would happen only if there were a measurement error. If there
were a contamination problem, and this could be verified, on only
that tested sample, you should expect the subsequent samples to
test with the rest of the group, if otherwise from the nature of
the excavation you expect the samples to be of the same date date.
>But if the "later" date is really a true
>later date, its later date ought to hold up under repeated measurements.
Agreed. BUT, this value MAY be the result of all material being
contaminated.
>This sounds simple, but there is an additional factor: if you have a
>contamination situation you need to get something from the same text
>that isn't contaminated--try a sample from a different area of the
>text to begin with--so that you don't risk measuring the same
>contamination twice (as may have happened with Zurich's 4QTQahat
>date, measured twice with both measurements agreeing in being
>anomalously early).
>
>But with 4QpPs(a) there is a way to get a real answer. The scribe
>who wrote 4QpPs(a) also wrote 4QpIsa(a) and 4QpHos(a). In the
>upcoming battery I have recommended to Fred, who is coordinating
>the arrangements, that we have samples from all three of these texts
>measured. If all three agree with the 1st CE 14C date for 4QpPs(a),
>then there is some real information that this is not an outlier situation
>but a true 1st CE date. And that would be the first evidence of such
>yet in Qumran scrolls study history.
This is good once the contamination problem is solved. As below, you
don't know how badly they're contaminated!
>On the other hand, let us suppose these three pesharim texts,
>whose dates of skins we expect to be contemporary because it
>is the same scribe, give 14C dates in agreement with the 14C date for
>pHab, in the 1st BCE. Then we would have a good reason to argue
>that the first 4QpPs(a) date, the 1st CE date, was, indeed, an outlier.
>
>This is consistent with A. Lerner's analysis so far as I can tell, and
>again thank you for the lucidity and clarity of the analysis.
>
>Greg Doudna
>Copenhagen
>
PLEASE, all these arguments would be tossed out of court for
evidentiary reasons. You CANNOT ensure that these ancient materi-
als have been secure from contamination since discovery. Literally
hundreds of people have been in their presence, offering incidental
tampering such as the unwitting use of Castor Oil. How many times
have these materials been handled barehandedly? Were examiners
masked? Were they properly clothed to avoid contamination
They have been a conservationist's nightmare. Just think of the
pictures of Solomon Schecter's pieces. A single match would have
destroyed the whole lot and his wife too.
Then there was the bland notice that acid washes might work.
Horrors! The leather trappings of King Tut's horses literally
melted during the 3300 years before they were found. Only the gold
trim gave any idea of the artifacts' shapes. (The leather was
badly tanned.) Acid is lethal to leather. Bases, by and large,
aren't, in fact leather is "cured" with it, and they can be non-
organic and are by and large excellent detergents. And, with an
ample supply of securely dated skins, control samples may be dated,
contaminated deliberately and not.
Please, while a properly professional evaluation is arranged for
and done, limit yourselves to boning up on how to deal with the
results.
Tom Simms (I fought too long to get the scrolls sprung for people
to keep on messing things up...)