Process of paleofloods in Guanting basin, Qinghai Province, China and possible relation to monsoon strength during the mid-Holocene

Prehistoric disasters including paleofloods and earthquakes in Guanting basin, Qinghai Province, China, and their impact on Neolithic cultures have attracted academic attention over the last decade. However, the process and mechanism of paleofloods in the basin remain unsolved. This paper describes studies of the periodicity and process of paleofloods in Guanting basin during the mid-Holocene and their relations to monsoon strength, based on geological and archaeological investigations, including analysis of magnetic susceptibility and color reflectance, application of radiocarbon dating and comparison with the stalagmite oxygen isotope record in Dongge Cave. During the mid-Holocene, paleofloods in Guanting basin began between 7550 cal a BP and 6510 cal a BP, and lasted to 2220 cal a BP at least. Four cycles of frequent followed by infrequent paleofloods have been detected. Three periods of infrequent paleofloods occurred during 4380–3970 cal a BP, 2850–2720 cal a BP and 2310–2140 cal a BP respectively. The other one took place around 5000 cal a BP, coinciding well with periods of weak Asian monsoon events. The process of paleofloods in Guanting basin during the mid-Holocene was possibly dominated by the precipitation changes responding to Asian monsoon strength.