Dating implications from solar bleaching of thermoluminescence of ancient marble

We present measurements of Thermoluminescence (TL) from Greek marble quarried at Paros, Naxos, Pendeli, Hymitos, Thassos, which have been known since ancient times. The results concern i) the solar bleaching of TL, ii) the solar transmission through marble thicknesses up to 16 mm, and iii) the implications for potential dating of ancient carved marble monuments/objects. The bleaching rate for marbles is very fast during the first hour of exposure. The solar penetration is at least 35 mm for long exposures. Beyond the 2 mm marble slab for exposure times 90–120 hours of sunshine, the residual bleached TL level is not reached. The bleached TL reaches a plateau which serves as the “zero time” upon which the archaeological TL dose subsequently builds up and gives the age of a marble monument.