A late Pleistocene refugium in Mediterranean North Africa? Palaeoenvironmental reconstruction from stable isotope analyses of land snail shells (Haua Fteah, Libya). (1st May 2016)

• Record Type: Journal Article
• Authors: Prendergast, A.L.; Stevens, R.E.; O'Connell, T.C.; Hill, E.A.; Hunt, C.O.; Barker, G.W.
• Is Part Of: Quaternary science reviews. Volume 139(2016)
• Page Start: 94
• Page End: 109
• Publication Date: 2016-05-01
• Subjects: Terrestrial gastropod -- Oxygen isotope -- Carbon isotope -- Helix melanostoma -- Palaeoclimate -- Epipalaeolithic -- Neolithic; Geology, Stratigraphic -- Quaternary -- Periodicals; Stratigraphie -- Quaternaire -- Périodiques; 551.79
• DOI: 10.1016/j.quascirev.2016.02.014
• Languages: English
• ISSNs: 0277-3791

Abstract

Abstract: The late Pleistocene to Holocene archaeological record of North Africa is key to understanding the emergence of anatomically modern humans into West Asia and Europe, and the broadening of subsistence strategies in the shift from hunter-gatherer to pastoral-agricultural lifeways. Some contend that these developments were modulated by major shifts in climate and environment. Evaluation of this hypothesis requires the pairing of local and regional climate records with well-dated archaeological sequences. The Haua Fteah archaeological site in the Gebel Akhdar region of Libya provides a key site to test this hypothesis as the cave contains one of the longest and most complete sequences of human occupation in North Africa as well as abundant material for palaeoenvironmental reconstruction. This study uses stable isotope analyses (δ 18 O and δ 13 C) of the terrestrial mollusc Helix melanostoma to construct a palaeoenvironmental framework for interpreting North African human-environment interactions from the Upper Palaeolithic to the Neolithic (∼30, 000 to 5000 years ago). The land snail stable isotope records from Haua Fteah suggests that cool arid conditions in the cave peaked during marine isotope stage (MIS) 2. This stage was, however, only marginally drier than previous and subsequent stages and coincided with an increase in occupation density in the cave. This suggests that the Gebel Akhdar may have served as an environmental refugium from the more extreme aridity in the surrounding Sahara and arid coastal plains for Late Stone Age (LSA) populations in North Africa. Conditions became progressively wetter towards the Holocene. However, generally wetter conditions were interrupted by two arid episodes at c. 8.0 ka and 7.3 ka that appear to coincide with regional changes reflected elsewhere in the Mediterranean basin. Highlights: Stable isotopes were analysed from archaeological land snail shells from Haua Fteah. These oxygen and carbon stable isotopes reflect changing aridity from MIS 1-MIS 3. MIS 1 was generally more humid, but with arid peaks at c. 8.0 and 7.3 ka. MIS 2 was generally drier, although not as arid as surrounding regions. During MIS 2 the Gebel Akhdar likely served as a refugium for human populations.