A micromorphological approach to inferring paleo-lake system phases: The case study of the Earlier Stone Age at Wonderwerk Cave, South Africa

Playa lakes are arid region ephemeral bodies of water that have been found in association with important archaeological sites. These lakes produce distinct sediments in response to changing hydrological and environmental conditions. To provide the means to more effectively study playa lake sediments, I developed an analytical protocol and a model that utilizes micromorphology and grain size distribution analysis of thin sections to identify and interpret paleo-playa lake phases preserved in intact archaeological deposits. To assess the potential of the analytical procedure, I applied it to thin sections collected from Earlier Stone Age deposits at Wonderwerk Cave, South Africa, where a playa lake system existed in proximity to the cave. The results of the study show that sediments produced during different playa lake phases can be distinguished according to a specific set of criteria identifiable through micromorphology and grain size distribution analysis.