Local Paleoclimate and Forager Land-Use in the Middle to Later Stone Ages of Morocco: An Analysis of Archaeological Stable Isotope and Biomarker Archives

Abstract

Studying the impacts of Late Pleistocene climate variability on Moroccan landscapes and human groups is an important step towards revealing the origins of Homo sapiens ecological adaptability, the conditions under which novel cultural practices such as hafted technologies, bone tools, and personal ornaments proliferated, and the long-term evolution of human-environment relationships through the Middle and Later Stone Ages (MSA, LSA). However, close, integrated comparisons between paleoenvironment and archaeological indicators of forager land-use have rarely been performed in North African Stone Age contexts. This dissertation examines changing local paleoenvironments in the Late Pleistocene of Morocco while simultaneously investigating the relationship between environment and land-use practices among MSA and LSA foragers with particular attention to site occupation intensity and resource use. Specifically, features of paleoenvironment are studied at the cave sites of Bizmoune, Contrebandiers, Taforalt, and Rhafas using a suite of proxies that include plant wax n-alkane stable carbon (δ13C) and hydrogen (δD) isotopes and distributions, branched glycerol dialkyl glycerol tetraether (brGDGT) distributions, land snail shell stable oxygen (δ18O) and clumped (Δ638) isotopes, and large herbivore tooth enamel stable oxygen and carbon isotopes. Paleoenvironmental results were compared with archaeological data relevant to forager land-use that include, depending on the site: frequencies of lithics, vertebrate faunas, and ornamental and non-ornamental marine mollusks; anthropogenic sediment inputs; human osteological data; and paleobotanical remains. Proxies detect fine-scale climate and environment changes within MIS 5e and late MIS 2. However, their impacts on human groups varied across locations and through time. Within the MSA, environmental change generally associates with resilience of local biotic communities. In some contexts, hominins adjusted to changing environments with minor land-use alterations, while in others we see greater change in mobility and site utilization. The most extreme land-use shift of all is recorded in the LSA at Taforalt and Rhafas, where foragers responded to the increased local productivity of nut-bearing trees with greater sedentism and resource intensification. In addition to local factors, rising population densities throughout the region likely pushed LSA groups towards broader diets, greater investment into food processing, and reduced residential movements in a manner not seen in the MSA.