Geoarchaeological study of the natural resources in the territory of the Roman town of Ammaia (Northeastern Alentejo, Portugal): case studies on water supply, building stone quarrying and opencast gold mining

This PhD-thesis presents the results of geoarchaeological research conducted in the ancient territory of the Roman town of Ammaia, located in the Northeastern Alentejo region in Portugal. It is focused on the exploitation of three major natural resources: water, granite and gold. In order to disentangle the considered research questions as comprehensively as possible, a geoarchaeological approach, integrating methods, techniques and knowledge base from a wide range of archaeological and geoscientific (sub)disciplines, was adopted in all three case studies. The studies further share the same base of fieldwork in a multidisciplinary frame of archaeologists, geomorphologists and geologists with different specialisations. The study of Ammaia’s water supply was aimed at identifying the main sources of water for use in the town, and at evaluating the possibilities of aqueduct construction for a continuous provisioning of the town. It resulted in the identification of the major sources of water and the reconstruction of two aqueduct routes to the town. The objective of the second geoarchaeological case study was to determine the provenance site(s) of Ammaia’s granite building stone. The abandoned quarry at Pitaranha, 6 km east of the town, was appointed as the producer of the typical Ammmaian granite. In the third case study, the existence of this large scale Roman placer gold exploitation on a site along the Tagus River, was verified and the respective roles of natural and anthropogenic processes in the Late Quaternary landscape evolution assessed in order to obtain a comprehensive understanding of the genesis of the present-day landscape in the area. Although much research is still needed before the full complexity of the ancient Roman economy and society will be understood, the author hopes that the studies presented in the framework of this PhD thesis unravel some of the burning issues regarding the exploitation and use of resources by the Roman town and that it forms a contribution to the still scanty knowledge on the Romanisation of the ancient province of Lusitania