October 29, 2024
by Gil Vilarinho
One of our 2023 Archaeology of Portugal Fellowship winners, Gil Vilarinho, provides us with an update:
As Roman stone exploitation was not hitherto subject to any systematic analysis in what is now Portugal, our understanding of what lithotypes were used and their respective sources was rather limited. As such, this project first aimed to determine possible main source areas for stones observed in Roman archaeological sites, contrasting the characteristics of each lithotype with geological charts and the modern ornamental stone industry catalogues. Following this first task, a desk-based assessment ensued, analyzing various geospatial datasets, such as aerial imagery and LiDAR data, archive records and geological and archaeological databases, mapping all the available evidence and defining areas of interest for subsequent fieldwork. This included a wide range of actions, from a simple photographic register to pedestrian and aerial surveys, in distinct areas of central and Southern Portugal. Being unable to mention all of them, I highlight a few.
The significant occurrence of a distinctly white, fine-grained marble in various Roman sites presently located in lower Alentejo suggested a regional source. Indeed, the subsequent investigation resulted in the identification of a possible significant quarry in the area of Serra da Adiça. Although the relative isolation of the site and the terrain did not allow thus far a ground analysis of these remains, we nonetheless managed to survey the area using UAV equipment, providing a clearer observation of the existing remains. In particular, it was possible to discern an extensive extraction area, currently covered by a dense vegetation canopy, and a rather interesting area of stone debris, apparently discarded in an organized manner along the perimeter, possibly associated with a stone working area where the material extracted could eventually have been cropped and trimmed and prepared to transport.
The Estremoz Anticline has been frequently considered the most important marble quarry area in this part of the Roman world, however, evidence for ancient exploitation has been relatively scarce. While mapping all the available archaeological data possibly related to this activity was the first step in our study of this area, a particular interest was devoted to the significative hydraulic structure known as Tanque dos Mouros, which could have powered stone sawmills. A small paper on this was published last year. Taking to the field, we resurveyed all the previously known quarrying remains, registering small evidence and larger areas with photogrammetry. In some cases, the surveys required targeted cleaning undertakings, as some elements of interest were covered by vegetation, recent soil deposits and modern quarrying debris. Surveying the surrounding areas also revealed previously unknown elements, particularly two well-preserved extraction areas. Additionally, collaborating with the local marble industry allowed us to track new evidence discovered during modern extraction works, especially a quarry displaying an interesting set of marks evidencing the use of saws to extract stone blocks, an exquisite technique not yet documented elsewhere in this region. Integrating this data into a wider research framework and working with several colleagues, some of the results obtained in the Estremoz Anticline will be published in an international peer-reviewed journal later this year.