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+--- Thread: C14 question (/showthread.php?tid=5308)
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C14 question - BAJR - 29th May 2014
Question oh folk who dabble deep into teh dark arts of C14.
I know what I think and I am pretty happy with what I see. However... is it possible taht these dates represent not 2 phases but 1 as they do.. per ce... overlap a bit.
670-410 calBC
536-391 calBC
560-390 calBC
541-395 calBC
543-396 calBC
516-379 calBC
550-390 calBC
410-350 calBC
406-354 calBC
359-390 calBC
C14 question - GnomeKing - 29th May 2014
what material is it
&
is this all the same material/s ?
is it all from the same sample (eg bucket), or from the same context (eg several buckets), maybe all from one intervention?
or are multiple samples from multiple interventions/contexts?
C14 question - Marc Berger - 30th May 2014
going for three phases and taking averages, ignoring the first date 540 as a phase in its own, something's happening like a rugby match around 380 which if you ignore leaves 465 where something like a football tournament is happening. Bring back in 380 and call it slightly less than 465, add a gregorian calendar, arabic numerals, consider a bit of duodecimal systems and the venerable Bede and it might be 3 or 4 days before or after a Tuesday. With a bit more knowledge about what distribution you are using and based on all the dates coming from a single cell living at the bottom of the sea off Greenland and the answer is 42....minuets plus or minus. What I would like to know is how you got so many dates out of a single cell found off the edge of Greenland at the bottom of a deep ocean and then if you did why is it relevant? or it could be that you have as many phases as dates as samples taken...did they all come from ditches and if they did, did you only have one ditch on site......I note that there is a gap between the dates which could be the big bang. You might like to try adding the coordinates between these dates, 3d if possible
ps why is the last date frontbackto?
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C14 question - P Prentice - 30th May 2014
cant be answered using the data shown. you need to explain how they relate stratigraphically and then do the chi-squared test to see if they are statistically consistent or not. what do you mean by phases? are you looking for distinct chronological actions or are you trying to decide if the, for instance, occupation of the site was distinct or continuous? i would ask one of those nice people at a lab - gordon cook in east kilbride is always helpful
C14 question - Dinosaur - 30th May 2014
BAJR Wrote:Question oh folk who dabble deep into teh dark arts of C14.
I know what I think and I am pretty happy with what I see. However... is it possible taht these dates represent not 2 phases but 1 as they do.. per ce... overlap a bit.
670-410 calBC
536-391 calBC
560-390 calBC
541-395 calBC
543-396 calBC
516-379 calBC
550-390 calBC
410-350 calBC
406-354 calBC
359-390 calBC
Yeah, I keep getting calibrated takes-yer-pick dates like that too, wrong bit of curve! Though of course occasionally you get that whole 2sigma range in 100 years jackpot...and then again, have charred grain at 41976-40602calBC in North Yorkshire - s'been checked, one of those statisticals sadly, bound to get a duff one occasionally...unless....:face-thinks:
C14 question - BAJR - 2nd June 2014
thanks for all that. all was useful. as it happens.. it was all the same material.. from various contexts across a site. charcoal in all cases ( no bone on site ) as it happens there is a new BAJR guide coming from SUERC in September...
C14 question - Jack - 23rd June 2014
Don't forget that the depositional processes of how your dated samples got into where you recovered them from is key to your phasing.
Otherwise your just phasing the death of the things the wood came from.
C14 question - BAJR - 24th June 2014
Quote:Otherwise your just phasing the death of the things the wood came from.Got that one
yes indeedy!
C14 question - Seedy Girl - 25th June 2014
You'd need to be asking questions of your charcoal too. Wood species: long-lived or short-lived species? Whether the charcoal sample was from the sap wood or heart wood makes a difference. Remember the 'old wood affect' too!
C14 question - Dinosaur - 27th June 2014
..and if it's a big wooden post-base, remember to sample the outermost rings (surprising and depressing how rarely that seems to be done), showed Seedy Girl that one, who says no on-the-job training :face-approve: