Publication Date:
2007-04-01
Description:
This paper reports the first detailed palaeogeographical analysis of the environmental context of late Mesolithic shell midden sites in the lower Tagus area and focuses on the lower Muge valley, which contains an internationally significant Mesolithic record. The lower Muge valley fill comprises buried estuarine and fluvial environments contemporary with Mesolithic settlement. Holocene environmental and palaeogeographic changes influenced Mesolithic settlement-subsistence and midden accumulation. The sudden appearance of large late Mesolithic shell middens throughout Portugal represents a process of increased visibility and preferential preservation of the archaeological record. Prior to ~6100 cal. BC, aggrading valley floor environments did not occupy the entire width of the present lower Tagus floodplain and any sites located in the early Holocene valley are currently deeply buried. Shell midden occupation on terrace levels followed the establishment of aggrading estuarine environments, containing productive shell beds, near the mouth of the lower Muge valley at ~6100 cal. BC. The critical factors in site choice appear to have been the nearby presence of (i) rich shell resources and (ii) freshwater environments. Long-term site occupation and (semi-)sedentary behaviour was favoured by the local presence, for over 2000 years, of rich resources from estuarine, freshwater and open woodland environments. Site abandonment (~5300—4800 cal. BC) coincided with the regional establishment of an open landscape (~5000 cal. BC) and the contraction of local estuarine environments (~5555—3800 cal. BC). The associated gradual decrease in resources and cultural interaction with the expanding early Neolithic communities may have influenced Mesolithic site abandonment.
Print ISSN:
0959-6836
Electronic ISSN:
1477-0911
Topics:
Geography
,
Geosciences
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