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酒西盆地青西凹陷下沟组中广泛发育的纹层状“白云质泥岩”和“泥质白云岩”,以其富含铁白云石、钠长石和方沸石等特殊的矿物组分和优越的油气地质条件 ,引起众多石油地质工作者的重视。以往的研究成果中 ,认为此两类岩石的成因均与火山作用有关。在该项研究中 ,依据此两类岩石的空间展布规律与北东向基底断裂的拉张活动密切相关 ,岩石的矿物组合和结构、构造特征主要显示热水沉积性质 ,并含有大量重晶石、地开石和出现微量闪锌矿、黄铜矿和方铅矿等特征的热液矿物 ,认为此两类岩石均属于湖相“白烟型”喷流岩 ,识别出各以铁白云石、钠长石、重晶石、方沸石和地开石为主的 6种热水矿物组合类型。在此基础上 ,划分出脉状充填型、水爆角砾型、盆地沉积型和区域扩散型 4种成因类型的喷流岩。文中首次提出喷流型热水沉积铁白云岩成因类型 ,探讨了此类白云岩在油气藏勘探与开发工程中的研究意义
The laminar “dolomitic mudstone” and “muddy dolomite” are extensively developed in the Xiagou Formation of Qingxi Depression in Jiuxi basin, and are characterized by their special mineral components rich in iron dolomite, albite and analcite The geological conditions of oil and gas, causing many petroleum geologists attention. In previous research results, it is considered that the causes of these two types of rocks are related to volcanism. In this study, the spatial distribution of these two types of rocks is closely related to the tension of the NE-trending basement faults. The mineral assemblages and structural features of the rocks are mainly characterized by hydrothermal sedimentation and contain a large amount of heavy crystals Rock, dickite and trace minerals such as sphalerite, chalcopyrite and galena are considered. Both types of rocks belong to the “white smoke type” jet lakes in the lake facies, , Albite, barite, analcime and dickite-based six types of hot-water mineral combination. On this basis, four types of jet rock are classified as vein filling type, waterblasting breccia type, basin depositional type and regional diffusion type. In this paper, the origin type of jet-flow hydrothermal sedimentary iron dolomite is first proposed, and the significance of this type of dolomite in exploration and development of oil and gas reservoirs is discussed