E. Arnold : Distributed in North America by Cambridge University Press
Abstract
A combined geomorphological, radiocarbon dating, archaeological and historical approach permits
a refining of the age of the coastal dune systems related to estuaries in the Gulf of Cadiz. Three dune systems
are distinguished in this paper. The oldest one, DI, which accumulated under prevailing WSW winds during
the first millennium BC, overlays both the occupational horizons of Late Neolithic-Early Copper Age (fourth
millennium BC) and the 'lithic workshop levels' (fourth to second millennia BC). The middle dune system, D2,
containing both Roman and medieval remains, accumulated between the thirteenth or fourteenth centuries and
the seventeenth century AD. The youngest D3 system is associated with the time of building of watchtowers
in the seventeenth century AD but extends to the present; it is related to SW prevailing winds. We explain the
absence of aeolian deposits prior to ~2700 cal. BP as the result of trapping of a large part of the sediment
supply in the estuaries, which starved the neighbouring beaches and aeolian settings. Aeolian accumulation
reached significant values when sedimentation in the coastal zone changed from being mainly aggradational
in the estuaries (~6500~2700 cal. BP) to mainly progradational in spit barriers and related dunes (post ~2700
cal. BP). The present analysis of aeolian systems suggests a non-direct correlation, at least in some cases,
between coastal progradation of spit barriers and aridity