Abstract: As a fault depression basin developed in the middle and late Quaternary,the Fuzhou basin consists of complicated deposit structures,including deposits of marine facies,terrestrial facies and marine and terrestrial alternating facies. The thick source alpha counter and flame-photometer are used to measure the content of radioactive elements (uranium,thorium and Potassium) of two drill holes (SZK1 and SZK2) strata in Fuzhou basin. Comparison of the content of radioactive elements with the result of spore-pollen analysis of one drill hole (SZK1) strata shows that the former changes with the variations of lithology and depositional environment. The content of radioactive elements in sediment is related to the scale of sediment granularity and lithology,being high in argillaceous sediments (e.g. silt and clay),low in sandy sediments and median in gravel strata. On the other hand,the contents of radioactive elements are relative to paleoenvironment,the warm and humid environment is propitious for high concentration of radioactive elements; while cool and dry climate is just the opposite.

Key words: U-Th-K radioactive elements content, granularity, paleoenvironment, drill hole strata, Fuzhou basin

摘要： 根据福州盆地2个钻孔地层放射性元素(铀、钍、钾)含量的变化特点,结合孢粉分析等结果,探讨了地层放射性元素含量变化与岩性、沉积环境的关系。沉积地层中的放射性元素含量与沉积物粒度、岩性等密切相关,在泥质沉积(如淤泥、黏土)中含量较高,在砂质沉积中较低,在砾石层中介于前两者之间。同时,放射性元素含量的高低还与古气候环境有关,温暖潮湿的环境放射性元素含量较高,凉爽干燥的环境含量较低。

关键词: U-Th-K放射性元素, 粒度, 古环境, 钻孔, 福州盆地