MULTI‐METHOD MARBLE PROVENANCE DETERMINATIONS: THE CARRARA MARBLES AS A CASE STUDY FOR THE COMBINED USE OF ISOTOPIC, ELECTRON SPIN RESONANCE AND PETROGRAPHIC DATA*

TLDR

The study explores the feasibility of applying a multi‑method approach to broader provenance problems. The authors present a multi‑method strategy combining petrography, stable isotope analysis, and electron spin resonance to assign the provenance of white marbles and differentiate the three main Carrara quarry basins (Torano, Miseglia, Colonnata). They employ 11 experimental variables, including quantitative colour and homogeneity measurements, petrographic, isotopic, and spectroscopic data, to build the classification model. Using a carefully selected subset of six variables, the method achieves 85 % resubstitution and 81 % jackknifed re‑assignment rates, and adding the remaining five variables does not improve performance.

Abstract

A multi‐method approach, based on petrography, stable isotope data and electron spin resonance spectroscopy for assigning the provenance of white marbles, is presented. A total of 11 experimental variables has been used, including the quantitative measurement of the sample colour and its homogeneity. On this basis we attempt to distinguish the three main quarrying basins of the Carrara district, that is, Torano, Miseglia and Colonnata. Such discrimination, extremely uncertain on the basis of the single techniques, may be performed with acceptable confidence’ using a properly selected subset of six petrographic, isotopic and spectroscopic variables. The final resubstitution and jackknifed re‐assignment rates are, respectively, 85% and 81%. Inclusion of the remaining five variables into the classification rule does not improve the results, but simply increases data overinterpretation. The practical possibility of using such an approach for more general provenancing problems is considered.