Achaeometrical Research in Hungary II., 1988
PROSPECTING and DATING - János CSAPÓ - Zsuzsanna CSAPÓ-KISS - János CSAPÓ JR.: How the amino acids and amino acid racemization can be used and with what limits for age determination of fossil materials in archaeometry
Standard error of a given estimate of age can be calculated 1 (x-xY S, =S VX J- + - r > yx \n s.s.x n = number of observations in the sample; n = 23 in this case, x = observed value of amino acid content in the unknown sample, X = mean amino acid content of the 23 samples and S.s.x = sum of (x - x )2 for the 23 samples. Standard error of the mean of three estimates yl + y2 + y3 , can be calculated as ' S y\ + S y2 + S y3 + ^ r x\x2 S pl S y2 + ^ r x1x3 S yl S y3 + ^ T x2x3 S y2p3 Confidence limits calculated as у ± (t21d f 0.05) ( s y ) can ^ e pl ace d on eacn est i" mate. Standard errors and 95% confidence limits for estimates of age of samples 1.18 and 2.25 are shown in Table 16. Sample 1.18 estimates vary from 562 to 600 years and average 580 years. All four sets of confidence limits overlap, indicating that the estimates are not significantly different (P < 0.05). We can be 95% certain that sample 1.18 is between 550 and 610 years of age. Estimates for sample 2.25 range from 297 to 344 years and average 326 years. All confidence limits overlap, and we can be 95% certain that the sample 2.25 is between 288 and 364 years of age. Increasing cysteic acid and decreasing cystine and tyrosine contents associated with the increasing age of wool samples have been shown to provide an accurate basis for estimating the ages of wool carpet and fabric. However, caution should be exercised in using the prediction equations presented in this paper. A different laboratory working with wool fabric of a different origin should analyse some samples of known age to either verify the applicability of these equations or to develop a set of equations appropriate for their samples. Acknowledgements The financial support of National Fund for Scientific Research (OTKA T 6653, OTKA T 14916) and Ministry of Education (MKM-15) is gratefully acknowledged. 44
