Marble for the Emperor—The Cover Slab of the Sarcophagus of Otto the Great in Magdeburg Cathedral, Germany

As part of a fundamental and comprehensive monitoring and conservation of the tomb of Emperor Otto the Great in the cathedral of Magdeburg, the question of the provenance of the marble cover slab of the sarcophagus was investigated. Within the restoration activities, two samples of the slab were taken for scientific provenance analyses, one sample of the white marble and another of the irregular grey bands. The following investigations were used for this purpose: analysis of the stable isotopes of O and C, and chemical analysis of a large number of trace elements, resulting in a large number of variables. For the simultaneous evaluation of these numerical results, statistical multivariate analysis was used for comparing the results with our database of approximately 7000 samples from ancient marble quarries and the data being referenced in this investigation are published and listed here. The results obtained clearly identify the quarries of Prokonnesos in the Sea of Marmara as the most probable source of the examined slab. This is in perfect agreement with petrographic analyses carried out on these samples.