Achaeometrical Research in Hungary II., 1988

BIBLIOGRAPHY - SUMMARIES - DATING

A method based on amino acid Racemization was developed and evaluated for determination of the Age of fossil bones. One hundred fossil bone samples of known Age from Hungary were collected and analysed for the D- and L-amino acid content. Because Racemization of amino acids is not only Age dependent but, is also affected by temperature, pH and metal content of Soil, These factors were corrected for by using C14 Age of the bone samples. This Age had previously been determined by a corrected C14 method. By plotting the D/L ratio as a function of time for the samples of known Age, and by using the half life of Racemization, calibration curves were established which subsequently were used for Age estimation of fossil samples of unknown Age. For This purpose, the D/L ratios of 2-3 amino acids were determined for each unknown sample and then the mean value of ages, estimated on the basis of the calibration curves, was then considered as the Age of the specific fossil sample. In the application of This method to dating of several Hungarian fossil bone samples, there were usually negligible discrepancy between the Age estimated from the amino acid Racemization with the Age obtained from C-14 dating. Notably, a high degree of caution were considered in the sample selection and sample preparation. Thus, unknown samples were mainly of similar origin as those for which the calibration curves had been made. The sample preparation procedure was also kept the same in detail for the samples of both known and of unknown Age. In This way, the method proved to give very reliable Results and may therefor be used as a general scheme in other dating applications. However, our calibration curves should not be used then because other samples may have been subjected to different environmental conditions (other temperatures, pH. etc. ) than the samples in This study. In those applications, other calibration curves should be derived for each different environment. Csapó J., Csapó-Kiss Zs., Költő L., Folestad, S., Orwar, O., Tivesten, A., Martin, T. G., Némethy S.: Age estimation of old carpets based on cystine and cysteic acid content = World Archaeological Congress-3. New Delhi, India, December 4-11 (1994). A method for evaluation of Age of wool carpets and textiles was developed based on the Age dependent alteration of amino acid composition of proteins. Samples of 23 wool carpets and textiles of known Age, obtained from the Hungarian Museum of Industrial Arts and the Hungarian National Museum were analysed for amino acid content. Results were compared with data obtained for contemporary, untreated wool and wool carpet. The cysteic acid content of wool increased with Age. The contemporary wool carpet contained 0.31 g of cysteic acid in 100 g of protein. Comparable figures were 1.87 g for 550 -year old carpet and 4.01-4.39 g for the 1600-1750-year old wool carpets. Cystine content decreased with Age corresponding figures being 7.88, 3.12, 1.19-0.97, respectively. Corresponding contents of methionine were 0.43, 0.21, and 0.20-0 and for tyrosine were 3.07, 2.11 and 0.20-0. Prediction equations were developed as linear regressions of Age of wool on cysteic acid, cystine and tyrosine contents. The 95% confidence intervals of estimates for two samples of unknown Age were estimates plus or minus 30 and 38 years. 280