关键词: 定鼎门剖面, 历史洪水事件, 粒度, 常量元素含量

Abstract: DDM profile lies outside the south gate (Dingding Gate) of Luoyang City (capital as Sui and Tang Dynasty), Luoyang Basin, Henan, China. Based on measurement and analysis of grain size, major element contents, the authors investigate sedimentary process of the profile and the historical flood events from Tang to North Song Dynasty in Luoyang. Grain size compose, the cumulative probability and frequency distribution curve indicate that there are three flood events in section 4, 6, 7; the major element contents result of SiO₂, Al₂O₃, Fe₂O₃ percentage changes reflects the migration of quartz, kaolin, and magnetic minerals and environment changes; the increase of quartz and decrease of kaolin and magnetic minerals in the bottom of section 6 and 7 prove the historical flood events reflected by the result of grain size analysis. Comprehensive analysis shows that there are two large-scale floods in the early and middle Tang Dynasty; there is a more serious sheet flood deposits process in North Song Dynasty. The sedimentary record is very consistent with historical documents.

Key words: DDM profile, historical flood events, grain size, major element contents