AUTHENTICATION OF ROMAN CORRODED LEAD ARTEFACTS FROM ARCHAEOLOGICAL SITES IN CALCAREOUS ENVIRONMENT IN JORDAN BY ELECTROCHEMICAL ANALYSIS

The process of authentication involves a wide variety of steps that are intimately linked and completely interdependent. In this research voltammetry of micro-particles (VMP) is used to date and authenticate a five late Roman lead balance weights. The chronology of the archaeological finds together with lead balance weights was estimated to be 4th century AD. A set of independent experiments: square wave voltammetry and electrochemical impedance spectroscopy (EIS) with the corresponding calibration curves obtained from several archaeological samples, which have been done in our laboratory. The collected sample were corroded under burial conditions in calcareous soils, are consistent with an attribution of the age of both studied lead samples. The ratio of PbO2 and the porous PbO which formed during the process of led corrosion in the calcareous environment reflects the date of corrosion. These attribution, however, must be taken with caution because of the differences in the aging process for the studied samples and the lead materials used for calibration purposes corresponding to the reduction of the PbO ‘continuous’ patina formed under the ordinary exposure of the lead piece to the atmospheric environment. The ratio between peaks resulted from the corrosion process of Ancient led and reference one revealed the date of corrosion. Assuming the 4th century AD chronology of the lead samples erection to be correct, it was found that the applied method provide the same result which is consistent with archaeological estimations.