Interruptions of the ancient Shu Civilization: triggered by climate change or natural disaster?

Environmental proxies of a stable carbon isotope, total organic carbon, free iron oxide, and particle size distribution in sediments as well as the stable carbon and oxygen isotopes in fossil human and animal teeth were used to reconstruct the history of climate change and natural disasters near the Jinsha Relic Site and to track their effect on the ancient Shu Civilization, which was established in the Chengdu Plain of southwest China during the late Holocene. In general, the late Holocene climate in the Chengdu Plain demonstrated a drying and cooling trend, with evident cooler events ~4100 and ~2700 a BP, which coincided with global climate changes. The ancient Shu Civilization was interrupted twice, and it included three stages—the Baodun (4700–3700 a BP), the Sanxingdui (3700–3150 a BP), and the Shi’erqiao (3150–2600 a BP)—that were slightly related to the abrupt climate changes that resulted from the collapse of the classic Sanxingdui Civilization, which was founded in a regional warm period. The abrupt increase in sand content in the sediment from the Jinsha Site coincided with the palaeoearthquake and palaeodam burst in the Longmen Mountains when the Baodun and Shi’erqiao desisted, indicating that a flood had occurred due to a dam burst and may likely have caused the ancient civilization’s destruction. Although the warm and humid climate, flat terrain and rich water resources prompted the prosperity of the ancient towns of Sanxingdui and Jinsha, frequent natural disasters, such as powerful earthquakes, landslide dams, and outburst floods, consistently affected the ancient Shu inhabitants.