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+--- Thread: Radiocarbon dates - from the horses mouth (/showthread.php?tid=4118)
Radiocarbon dates - from the horses mouth - P Prentice - 13th October 2011
not start again but use with caution - have you recalibrated old dates? -the error factor often still makes even single object dates worthless
Radiocarbon dates - from the horses mouth - Dinosaur - 13th October 2011
P Prentice Wrote:not start again but use with caution - have you recalibrated old dates? -the error factor often still makes even single object dates worthless
Afraid around here am usually using C14 to tell what era things are, don't usually have the advantage of finds like what they have on fancy sites down south - site I've been digging since April has produced 5 scrappy non-diagnostic flints and a practically non-existent skelly so far, no pot or other dateables - so even broad date-ranges have their uses, personally in an ideal world I wouldn't touch little bits of charcoal from the decay-cone within a postpipe with a barge pole, but if that's all you've got......hence my recently acquired enthusiasm for OSL!
Radiocarbon dates - from the horses mouth - Jack - 14th October 2011
I'm pushing for multiple determination dating (where you suitable stuff to date - big dumps of grain, carbonised residues, good bones etc) and bayesian statistics............it is after all recommended in the north-eastern research framework, Understanding the British Iron Age and even in the resource assessment for Yorkshire.
Even if you get two measurements from the same event (e.g. leg bone and arm bone from the same skelly) you end up with a massive increase in confidence (statistically and in the world of peer review) in the date ranges. Do some statistics (pooled mean I think - although my maths is shoddy) and it should refine the date range without compromising the error statement.
Do more than two and you start to get really useful dates.
But even getting dates for several things that are thought to be contemporary can cause surprises and make your remains much more significant (for those of use doing post-excavation assessments begging for more money!). Not allowed to go into details.......but on a recent project had something that was thought to be early medieval, (definitely Anglo-Saxon apparently by its form) but pushed for a RC date anyway to see if it was in the transition or later. The date came back as early 1st century to 3rd century AD making it very very interesting (possibly unique!).
This is a warning to every archaeologists who doesn't realise.....
The dating of many things (pottery, burial traditions, structural forms etc etc) is base solely on old typologies of artifacts that are often wrong.
A great modern example of radiocarbon dating is the work by Alex Gibson and Alex Bayliss at Duggleby Howe, North Yorkshire. in The Archaeological Journal vol 166, 38-78
It also shows just how much evidence (for making up your stories) you can actually get by using multiple scientific techniques. Not read it myself yet though.....just skimmed through it.
Radiocarbon dates - from the horses mouth - P Prentice - 14th October 2011
i think you mean weighted mean - which isnt the same as being statistically consistent but otherwise i agree that a suite of dates is what is needed
Radiocarbon dates - from the horses mouth - Dinosaur - 14th October 2011
Jack Wrote:I'm pushing for multiple determination dating (where you suitable stuff to date - big dumps of grain, carbonised residues, good bones etc) and bayesian statistics.....
My recent experience of getting no less than 9 dates for something is that you, err, get almost exactly the same date 9 times, for 9 times the cost....
Radiocarbon dates - from the horses mouth - maurizio feo - 14th October 2011
It is not possible for me to do it right now, but I think I shall ask a few (presumably stupid) questions later on (tomorrow or later) about carbon dating notations.
I must admit I have at least three tipes of difficulties:
I'm a newcomer.
I'm not an archaeologist
My mother tongue isn't English
Probably, there are even more I'm not aware of...:face-thinks:
Radiocarbon dates - from the horses mouth - moreno - 14th October 2011
Maurizio,
Strike three! Then again yer in good company. What is your interest in 14C dating, and I don't mean cup size.
Radiocarbon dates - from the horses mouth - GnomeKing - 14th October 2011
i like your style maurizio feo
Radiocarbon dates - from the horses mouth - maurizio feo - 15th October 2011
OK, thank you both for the encouragement...
My question is about a paper I found in the Internet. It' by Robert Tykot and it's about carbon dating of a number of different sardinian locations: its title is: "Social Dynamics of the prehistoric central mediterranean" (Univ. London - 1999)
In the table reporting his (and other researchers') results there appear 7 columns, some of which I badly need help with (because I cannot find any agreement between this table and the Author's final conclusions)...
From left to right they read: (1) Site, (2) Context, (3) Lab N?, (4) 14C age, (5) Error, (6) 2sigma Calibrated age range (CALIB 3,0,3), (7)Reference. I do not think that column (3) and (7) are of any interest here and column (1) and (2) only serve the purpose of making the example complete.
In particular, what baffles me is the actual final dating of nuragic towers.
One example: (1) Nuraghe Duos Nuraghes, (2) Tower A floor , (3) I-14,774, (4) 4180, (5)+- 320, (6) cal. BC3333 (3075, 3067,3040) 2915, (7) MMA 3(1992): 278.
According to my (scarce and primitive) understanding, I should subtract 1995 from 4180 and then allow for a mistake of plus or minus 320 yrs.: this procedure should yeld two hypothetical dates (in my reckoning: 1905 - 2545) high and low limits to which the building of the tower may be attributed. In column (6) I dont find any of these numbers, though. Not that this bothers me, really, though if any of you can explain my mistake I would very much appreciate it...
My final question is, in fact:
How does this table (existing for many different Nuraghi, of course, with slightly different figures) accord with the Author's conclusions that attribute the prehistoric period Nuragic I to 1600-1300 a.C.?
Thank you in advance, for your patience
Radiocarbon dates - from the horses mouth - maurizio feo - 15th October 2011
I would like to add that Tykot himself is not very detailed, when he writes about the date of these nuraghi (Brunku Madugui, Barumini and Duos Nuraghes) he simply states "they are the only ones for which evidence seem to place them earlier than 1.700 b.C.". If so, this would put them in the antecedent period (called Bunnanaro B), not in the Nuragic I, where Common Consense does at present. He also refers of an other case (nuraghe Noeddos - Trump, 1990 dated 1750 - 1500 b.C) in which the date precedes the Nuragic I.
But these figures, again, are not clear to me: I cannot obtain them from the data he notates in his table. :o)
Now this may not seem important to people who research mainly or preferably among English Archaeology items and problems, but I assure you that in Sardinia this is presently a rather [B]hot topic[/B, as are the functions of the nuraghi, the rebuilding, their total number and almost everything about them ].}
I really hope some one will be so kind as to help me out of my empasse in interpreting C14 dating...
Thank you.