等时格架下陆相页岩多尺度岩相精细识别及控制因素分析——以渤海湾盆地东营凹陷为例

由于陆相页岩控制因素的多样性与复杂性,使得页岩岩相的精细识别及预测具有一定的难度,同时,页岩岩相发育的控制因素也一直没有明确。通过近年来对渤海湾盆地东营凹陷泥页岩岩相及控制因素的持续研究,总结了不同级次等时地层格架下陆相页岩岩相多尺度精细识别标志与发育特征,提出了2种尺度的控制因素。岩相可分为层耦、层耦组、岩相域和岩相层序4个尺度,其中层耦受古生产力、季风、氧化—还原条件联合控制,层耦组—岩相域—岩相层序受物源、气候、构造联合控制,多种因素叠合造就了陆相页岩岩相的复杂性与多样性。研究成果对于系统刻画中国陆相页岩岩相特征、深入理解不同尺度岩相形成机理具有重要意义。

Identification and controlling factors of multi-scale lithofacies for continental shale under an isochronous stratigraphic framework: a case study in Dongying Sag,Bohai Bay Basin

At present, due to the diversity and complexity of terrestrial shales, it is difficult to identify and predict the shale facies precisely. At the same time, the controlling factors for shale development are not well understood. The study of shale facies and controlling factors in the Dongying Sag has allowed the identification of features of multi-scale lithofacies in lacustrine shale of different grades, and further identified two controlling factors. Lithofacies can be divided into layer coupling, layer coupling group, lithofacies domain and lithofacies sequence. The layer coupling is controlled jointly by paleoproductivity, monsoon and oxidation-reduction, while the layer coupling group-lithofacies domain-lithofacies sequence are controlled jointly by material source, climate and structure, thus resulting in the complexity and diversity of continental shale lithofacies. The results can be used to systematically understand the multi-scale characterization and research of lacustrine shale lithofacies.