ABSTRACT
The Sado River Drainage Survey project (2004-2008)
was designed to fill a significant gap in our knowledge of
the prehistory of Portugal. Southern Alentejo constitutes
nearly one third of the total land mass of continental Portugal,
but has received comparatively little attention from
Palaeolithic archaeologists. Practically nothing was
known about the prehistory of the Sado River basin,
which includes the southern Alentejo plain, before now.
The results of the Sado River Drainage Survey (SRDS)
indicate that the Sado River basin was likely occupied at
low population densities during the Middle Palaeolithic.
There is some evidence for a Lower Palaeolithic presence
but little or no evidence of an Upper Palaeolithic occupation.
The emerging pattern suggests either an occupational
hiatus or a major shift in settlement pattern towards
the end of the Middle Palaeolithic. Possible explanations
for this pattern, including aridification driven by climate
change, are explored here