Burning, Cleaning, Dumping, and Dissolution: Site Formation Processes and Stratigraphy of Pre-110,000-Year-Old MSA l Deposits in Cave 1, Klasies River Main Site, South Africa

Abstract

Understanding the formation and stratigraphy of sequences in southern African Middle Stone Age (MSA) sites is vital for contextualizing evidence for the evolution of modern human behaviors and cognition. Deposits at these sites often have complex formation histories, typically involving a range of anthropogenic, geogenic, and biogenic depositional and post-depositional processes, and micro-laminated deposits are common. Consequently, archaeological micromorphology and related micro-analyses are now routinely a major component of MSA geoarchaeological research in the region. In the past few decades, microscale studies of the formation of anthropogenic features and deposits at MSA sites have begun to provide important behavioral information, including evidence for varying occupational intensities and the structuring and maintenance of living spaces. Here, a microscale geoarchaeological approach is applied to deposits dating to the MSA I cultural phase (> 110 ka) in the Cave 1 Witness Baulk. The results show that humans played a considerable role in site formation and that subsequent diagenesis affected the guano, charcoal, ash, and shell, with particular impact on the carbonates which were variably dissolved, altered, or recrystallized. This latter process helped to preserve ash through reduced dissolution potential. Spatial and temporal patterns in these factors influence the macroscopic properties of the deposits in any particular area, with significant implications for the correlation of extant deposits across areas excavated at low resolution during the 1960s. Different, variably preserved, anthropogenic features and deposits were found to make up a significant proportion of the deposits. Inferred behaviors range from repeated long-term low-intensity use of individually stacked hearths to the formation of dumped deposits (including shell middens) due to repeated hearth maintenance and patterned discarding of food waste during more intensive occupations. Differences in occupational intensity and frequency both within and between the two recognized MSA I members could indicate adaptation to changing conditions as temperatures and sea levels fluctuated during Marine Isotope Stage 5e and early Stage 5d, but changes in geogenic depositional rates over the same period could skew our perception of occupational frequency. The current limited and low-resolution dating evidence prevents correlation with any specific event/s, which might have affected behavior and/or depositional rates.