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C-14 controversy

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  • David Hall
    Was reminded of this subject while reading CANE, J. Sasson, 2000, V. II, Choronology: Issues and Problems, Frederich Cryer.   The plus or minus accuracy
    Message 1 of 1 , May 4, 2009
      Was reminded of this subject while reading CANE, J. Sasson, 2000, V. II, Choronology: Issues and Problems, Frederich Cryer.
       
      The plus or minus accuracy rating of 70-100 years for the first millenium B.C. was in line with estimates I had read in a recent article about the ancient Egyptian chronology from the time of Thutmosis III in the LBA mid-second millenium being about plus or minus 100 years.  Plus or minus 100 years is a range of accuracy spanning about 200 yrs. if one eliminates data points that are obvious outliers  
       
      According to F. Cryer callibration charts have been designed for regional variances in callibration.  I had not guessed the distribution of C14 in the atmosphere greatly differed from region to region.  I had suspected that variances in data might be caused by contamination of samples.  While I do not have the chemical background to designate a path whereby C14 might be more or less reactive to solutions in ground water than C12.  I have knowledge of cases where wood was replaced or fossilized by solutions containing silicates/agate/opal, iron pyrite, and calcium or calcium-magnesium carbonates.  In the abscense of replacement of cellulose and lignim with amorphous minerial concretion, there is the possiblity that some C-14 or C-12 might react with solutions and be transported from the sample, or new dissolved C-14 might be added to a sample.
       
      Turning to the Internet I found there are a number of articles about the contamination of C-14 samples by groundwater. 
       
      Findings at Tel Rehov indicated two grain samples from the same fiery destruction strata varied in age by 80 yrs.  I assume this was a typical case, else why was it published?
       
      David Q. Hall
       




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