【摘要】 三江盆地富锦隆起下白垩统发育厚层暗色泥岩,为了恢复这套暗色泥岩的古环境,进行了系统的野外地质调查和取样分析。地球化学特征显示:Sr/Ba比值为0.08~0.20,碳氧同位素系数Z值为106.62~116.03,表明下白垩统为淡水沉积环境,盐度变化相对稳定;Ti含量为3 183×10-6~5 239×10-6,Sr/Cu比值为2.53~35.84,Fe/Mn比值为21.15~96.95,表明下白垩统处在温暖湿润的气候条件下;Cu/Zn比值为0.09~0.21,V/V+Ni比值为0.77~0.81,Ce的异常指数为-0.06~0.01,表明下白垩统处在还原环境中。孢粉化石特征显示:Protopodocarpus sp.(原始罗汉松粉未定种)、Aratrisporites fischeri(Klaus)Playford et Dettmann(弗歇尔离层单缝孢)等所指示的植物生长环境为温暖湿润的气候环境。烃源岩元素地球化学特征指示该套地层具有较好的生气前景,温暖湿润的还原环境为有机质生成提供了良好的条件。更多还原

【Abstract】 Based on systematic geological survey and sampling analysis,this paper restores the palaeoenvironment of dark mudstone of Lower Cretaceous largely developed in Fujin uplift of Sanjiang Basin. The geochemical characteristics show that ratio of Sr / Ba varies from 0. 08 to 0. 20 and coefficient of carbon and oxygen isotopes varies from 106. 62 to 116. 03,which indicates the Lower Cretaceous developed in a freshwater sedimentary environment with stable salinity. Content of Ti varies from 3 183 × 10- 6to 5 239 × 10- 6,ratio of Sr/Cu varies from 2. 53 to 35. 84 and ratio of Fe / Mn varies from 21. 15 to 96. 95,which indicates the Lower Cretaceous developed under warm humid climate conditions. And,ratio of Cu / Zn varies from 0. 09 to 0. 21,ratio of V /( V + Ni) varies from0. 77 to 0. 81 and abnormal index of Ce varies from- 0. 06 to 0. 01,which indicates the Lower Cretaceous developed in a reducing environment. The palynological fossils,Protopodocarpus sp. and Aratrisporites fischeri( Klaus)Playford et Dettmann indicate warm and humid environment for the plants growing. Geochemical characteristics of source rocks indicate a prospect for gas generation,and the warm and humid reductive environment provided favourable condition for organic matter.更多还原