摘要
Through deeply field survey, a Holocene loess-soil profile with interbedded flood slackwater deposits (SWD) was found in Xianyang of the middle reaches of the Weihe River, which recorded the information of palaeoflood events. In order to achieve OSL ages, 9 luminescence samples were collected and postIR-OSL measurements were used with single-aliquot regenerativedose (SAR) protocol. Grain-size distribution and magnetic susceptibility were also analysed so as to research the occurrence and cause of palaeoflood. The result shows that the fast component is dominant in OSL signals of quartz grains (40~63 μm), which is suitale for postIR-OSL measurements. This paper shows that the Weihe river in transform period from rainy to dry. The highly variable, unstable and catastrophic climate was the cause of extreme palaeofloods occurrence.