相山李家岭铀矿床热液蚀变作用地球化学特征

发布时间：2019-02-12 08:22

【摘要】：李家岭铀矿床是最近几年在相山西部发现的一个铀矿床。矿床热液蚀变特别发育并存在明显的蚀变分带现象,在对钻孔岩心样详细的野外和室内岩相学观测基础上,将李家岭铀矿床铀矿化段分为矿化中心带、矿旁蚀变带、近矿蚀变带和远矿蚀变带,其热液蚀变强度依次减弱。运用标准化Isocon图解法表明,热液蚀变带中,CaO、FeO、Fe_2O_3、Na_2O明显增加,这与发育赤铁矿化、钠长石化、碳酸盐化相一致;K——2O明显降低,这是由于钠长石交代钾长石造成K的大量迁出;而MnO、MgO在各蚀变带中呈现"此消彼长"的特征,显示出热液蚀变交代过程中并不是简单地扩散渗滤交代,可能存在对流平衡的元素迁移方式。Th、Y、Zr、Hf等微量元素变化与铀含量一致,对铀矿化具有很好地指示作用。HREE与铀矿化关系密切,随着蚀变程度增强,HREE明显增加,显示成矿流体富含HREE,并具有深源性。
[Abstract]:Lijialing uranium deposit is a uranium deposit discovered in the west of Xiangshan in recent years. The hydrothermal alteration of the deposit is particularly developed and there are obvious altered zonation phenomena. On the basis of detailed field and laboratory petrographic observation of the core samples of the borehole, the uranium mineralization section of the Lijialing uranium deposit is divided into the central mineralization zone and the alteration zone beside the ore deposit. The hydrothermal alteration intensity of the near ore alteration zone and the distant ore alteration zone decreases in turn. The standardized Isocon diagram method shows that the CaO,FeO,Fe_2O_3,Na_2O increases obviously in the hydrothermal alteration zone, which is consistent with the development of hematitization, albite and carbonization. The decrease of K-2O is due to the migration of K from albite to potassium feldspar. However, MnO,MgO has the characteristics of "rising and falling" in each alteration zone, indicating that the hydrothermal alteration and metasomatism process is not simply diffusion percolation, and there may be a convective equilibrium element migration mode. Th,Y,Zr, The change of trace elements, such as Hf, is consistent with the uranium content, which is a good indicator of uranium mineralization. HREE is closely related to uranium mineralization. With the increase of alteration degree, HREE increases obviously, indicating that the ore-forming fluid is rich in HREE, and has deep source.
【作者单位】：东华理工大学地球科学学院;中国地质大学(武汉)资源学院;
【基金】：国家自然科学基金项目(U1403292)
【分类号】：P619.14

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