Prehistoric archaeological site changes and their causes with paleofloods in Southern Shanxi Province, China

Abstract

Southern Shanxi province is renowned for its abundant prehistoric human activities (from paleolithic to Zhou dynasty), and thus holds significance in the study of the origins of Chinese civilization. Exploring shifts in human activity can offer insights into civilization development. Yet, there's a notable gap in research on how climate affects ancient human societies and their adaptive responses, especially concerning extreme weather events. This study investigated spatiotemporal characteristics of prehistoric settlement distribution of archaeological sites of southern Shanxi province, and then analyzed a natural geological profile, Songcungou (SCG), located about 2 km west of a famous Taosi archaeological site. SCG profile is primarily composed of eolian loess-paleosol, punctuated with layers of embedded fluvial gravel, and Optically Stimulated Luminescence (OSL) dates, grain sizes and geochemical elements were used to investigate the influences of climate changes on settlement distribution. The results of spatiotemporal distribution of settlements showed that archaeological sites of the early Yangshao (∼7–6 ka; ka is 1000 years ago) period were mainly distributed in loess platforms under the influenced of mountain torrents. Archaeological sites near the Fenhe River first increased during the mid-term Yangshao (∼6–5.5 ka), then decreased in the late Yangshao (∼5.5–5 ka) period when the climate becomes cold and dry, Rised again in the Longshan (∼5–3.9 ka) period. However, climate shifts and floods in late Longshan (∼4.4–3.9 ka) likely caused a decline in settlements, paving the way for Xia (∼3.9–3.5 ka) culture in southern Shanxi, with political and societal factors overtaking climate as the main influence on human settlement patterns by the Shang and Zhou dynasties (∼3.5–2.3 ka). Furthermore, stratigraphic observation and OSL dating revealed two flood events in the Taosi region, which occurred at about ∼14.5–12.5 ka and ∼6.8–6.3 ka. The mountain torrents documented in Gravel Zones I and II were predominantly triggered by intense, short-duration precipitation events, compounded by factors such as saturated soil conditions, limited surface vegetation, and steep geomorphic features.