Early-Mid Holocene Cultural and Climate Shifts in NW Africa: Paleoenvironmental Reconstruction Using Stable Isotopes of Land Snail Shells

Abstract

The long-term response of humans to climate/environmental change can be assessed by studying proxy climate records extracted from well-dated and well-preserved archaeological sequences. Two Holocene Capsian sites from NE Algeria, NW Africa, document a marked change in subsistence strategies near 8,200 cal yrs BP. To examine the potential relationship between cultural shifts and environmental change, we analyzed the stable isotope composition (δ¹⁸O and δ¹³C) of archaeological shells of the terrestrial gastropod Helix melanostoma from the early to mid-Holocene (11,000 to 7,000 cal yrs BP). Harvested land snails are good local paleoclimatic proxies and primarily inform about humidity and vegetation type in the region. The preliminary results suggest conditions were notably wetter between ~10,000-8,500 cal yrs BP, coinciding with the African Humid Period (AHP), whereas the environment turned significantly drier at around 7,500 cal yrs BP, immediately after the 8,200 cal yrs BP climate event. These results suggest that noticeable humidity fluctuations occurred during the Early Holocene in NE Algeria and could have impacted the economy and strategies of prehistoric human groups in the area.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018