Marble for the churches

Borgund, boasted three or four churches in its heyday. Worked marble blocks from Borgundgavlen, some with architectural details, and in the last remaining church suggest that some of the churches were built of marble ashlars. The present investigation aims to identify the geological source of the marble ashlars from Borgund and compare the results with marble found in other medieval churches and church ruins in the Sunnmøre district. Samples were collected from 12 marble deposits and six churches/ruins. Since all the relevant marble deposits in the region are mineralogically and texturally similar, provenance sourcing could not be carried out visually or by petrographic examination alone. Moreover, modern quarrying of marble for lime mortar has eradicated traces of medieval marble extraction. Consequently, we studied the provenance of the marble using C, O and Sr isotopic analyses. The isotopic data provided evidence for a major source of marble for the Borgund Churches, most likely the nearest sizeable marble deposit. Other churches in the region displayed different isotopic signatures, indicating that several marble quarries were employed in the 12th century, showing a complex pattern of resource acquisition.