Site formation processes and site use in the Late Pleistocene and Early Holocene: micromorpohology and FTIR analysis at the cave sites of Xianrendong and Yuchanyan

Abstract

This research reconstructs site formation processes and activities of the inhabitants of two cave sites in south China, Xianrendong and Yuchanyan, where the earliest pottery in the world has been discovered. The goal is to broaden existing understandings of human behavior of Late Pleistocene and Early Holocene Chinese hunter-gatherers, through the production of data types rarely gathered at a Chinese Palaeolithic site. I use the geoarchaeological technique of micromorphology – microscopic observation of thin sections of oriented intact sediment samples to identify their components and nature – and micro-Fourier Transform Infrared Spectroscopy (μ-FTIR) a technique used to obtain the molecular composition of materials used here to detect changes associated with fires. In this study, I reconstruct occupational patterns over time and show how flooding events as well as cave-specific climatic patterns, such as freeze/thaw and dripping water affected human choices of living spaces. Analysis of sediments derived from human use clarify details of such activities as building and cleaning fires, and constructing clay surfaces. Analytical results indicate that the inhabitants of Xianrendong maintained fires with consistently low temperatures, while at Yuchanyan through control of oxygenation and preference of wood fuel humans could maintain their fires between 500 and 700 Co for long periods of time. The low temperatures support the hypothesis from a preliminary study of the ceramics that pottery at Xianrendong was made without the use of kilns. Thoroughly consumed wood fuel at Yuchanyan indicates sophisticated pyro-technological knowledge and a possible preference for boiling as a cooking method. Finally, micromorphological analyses confirm the undisturbed nature of the sediments and so corroborate the reliability of a recent radiocarbon date of 20 ka cal BP for the earliest pottery-bearing layers. Micromorphological research reveals these early peoples’ knowledge of the physical properties of fires and clays, as well as their behavior of separating usable space into activity areas. In combination with the published systematic analysis of the faunal and botanical remains and of the material culture from these sites, my results provide a high-resolution account of life in these two sites. This study will be an important precedent for the further, systematic use of these geoarchaeological techniques in Chinese archaeology.