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泥火山是地质流体活动的结果,喷发需具备泥浆源、泥浆运移通道和水补给3个条件。对乌苏泥火山8个喷口泥浆进行岩石地球化学分析,轻稀土元素富集,重稀土元素亏损,轻、重稀土元素平均比值为6.81,泥浆中富集大离子亲石元素Ba、Rb等,高场强元素Nb、Ta强烈亏损,Th弱亏损,(La/Yb)_N值为5.47,Ce/La值为2.22,球粒陨石标准异常值δEu显示中等负异常(0.760~0.805);Sr/Ba值为0.33~1.01(平均值0.60),表明源岩为陆相沉积且古盐度较低,Ce/La(2.22)、Ce_(anom)(-0.007)、V/(V+Ni)(0.78)值均指示源岩形成于还原环境。稀土、微量元素分析及地层对比分析表明,乌苏泥火山源岩来自于下侏罗统八道湾组、三工河组,为河流沼泽相-半深湖相含煤地层代表的弱还原-还原沉积环境,源岩的最大埋藏深度为7~8km。泥火山源岩的研究为指示油页岩、烃类物质的位置提供了证据。
Mud volcano is the result of geological fluid activities, eruptions need to have mud source, mud migration channel and water supply three conditions. The geochemical analysis of 8 spout muds in Wusu Mud volcano shows that the light rare earth elements are enriched, the heavy rare earth elements are depleted, the average ratio of light and heavy rare earth elements is 6.81, and the mudstone is enriched in large ion lithophile elements such as Ba and Rb (La / Yb) _N value is 5.47, Ce / La value is 2.22, and chondrite meteorite standard anomaly δEu shows medium negative anomalies (0.760 ~ 0.805); Sr / Ba (0.60 ~ 1.07), and the value of 0.33 ~ 1.01 (average 0.60), indicating that the source rocks are continental sediments and have lower ancient salinities with Ce / La (2.22), Ce anoma (-0.007), V / (V + Ni) ) Values indicate that the source rocks formed in the reducing environment. Rare earth, trace element analysis and stratigraphic correlation analysis show that the Wusu mud volcanic source rock comes from the lower Jurassic Badaowan Formation and Sangonghe Formation, which is a weak reduction-reduction deposition represented by coal-rich strata in the river marsh facies-semi-deep lacustrine facies Environment, the maximum buried depth of source rock is 7 ~ 8km. Mud volcanic source rocks provide evidence for the location of oil shale and hydrocarbons.