A Multianalytical Approach to Identifying the White Marbles Used in Roman Imperial Sculptures from Tarraco (Hispania)

A selection of the most outstanding white marble sculptures from Tarraco has been archaeometrically studied to know more about the marble sources and their respective artistic workshops. All are imperial portraits of the 2nd century AD (Trajan, Hadrian, Lucius Verus and Marcus Aurelius) and a thoracata bust assigned to Hadrian, found on display at the National Archaeological Museum of Tarragona (MNAT). The well-established multimethod approach, combining petrography, cathodoluminescence, C and O isotopes and Sr and Mn trace element composition, has revealed the use of different very fine- to fine-grained marbles of the highest quality exploited in classical times. In contrast to what was thought until now, in which all the pieces had been assigned to Luni-Carrara, this present study identifies the use of two varieties of the recently discovered site of Goktepe near Aphrodisias and Paros-lychnites marbles, being Carrara, in minority. This study confirms the importance of strontium concentration and the contribution of cathodoluminescence to distinguish Goktepe from Carrara marble, while carbon and oxygen isotopes were crucial for the identification of Cycladic marble. Finally, in line with recent published interdisciplinary studies, the marble provenance forces us to rethink the discourse on the use of marble, its sculptural workshops and its distribution in this temporal context.