Research into the Mesolithic period in Portugal has been dominated by the famous shell middens, particularly those located in the estuaries of the rivers Tejo and Sado (central/south of Portugal), known since the second half of the 19th century. In conjunction with other archaeological sites discovered in 20th century along the southwest coast (Estremadura, Alentejo and Algarve regions), the panorama of the Portuguese Mesolithic was defined by a littoral settlement model, leading some authors to suggest the depopulation of some parts of the territory, especially upon the north and the inland, after the advent of the Holocene. 

However, more recently, new findings in some regions previously considered, according to that model, as uninhabited, provide a more diverse and enriched picture of postglacial Portugal. One of these regions is the north west of Portugal, where in the 1990's one of the authors (J. Meireles) implemented a research project oriented to the recognition of a settlement model associated with the last hunter-gatherer prehistoric communities of the region, in the medium altitude mountain areas. This project had as its reference the surveys and work developed in the neighbouring Spanish region of Galicia, where a continuous Epipaleolithic/Mesolithic settlement pattern was observed in its central and southern mountain ranges.

Therefore, a set of consistent and detailed field surveys took place in the mountains of NW Portugal, leading to the discovery of the archaeological site named ‘Rock Shelter 1 of Cerdeira Valley', a granite rock shelter situated in Cabreira Mountain (Vieira do Minho, Braga, NW Portugal, max. alt. 1,262 m).

The campaigns of excavations undertaken permitted the identification of two combustion structures, from which charcoal samples provided two C-14 dates, as well as a significant stone tool assemblage (around 30,000 pieces), that established the prehistoric occupation of ‘Rock Shelter 1 of Cerdeira Valley' between the Late Mesolithic and the Early Neolithic.

This archaeological site and its body of evidences are being analysed within the context of an ongoing Phd project developed by one of the authors (P. Xavier), through two mutually related lines of research. The first one relates to the complete technological and typological study of the lithic assembly, identifying the objectives of the stone tool production, i.e., lithic production systems and related chaines operatoires; and the second concerns itself with the classification and characterisation of different raw-materials (of a local and exogenous nature) exploited by the prehistoric communities and, wherever possible, to make some additional considerations about the economy of abiotic resources and raw material procurement - exploited areas, potential sources, processes of exchange and lithic mobility.

This text aims to present and discuss some preliminary results of our work in progress.