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在密西西比中部几种类型的以沉积岩为主岩的金属矿床中。在白垩系岩层最底层富含铅和锌的油田卤水内发现了局部含有有意义的地球化学微量金属含量,进一步证实了沉积层间水和这些矿床之间的成因联系。早白垩世岩层的卤水样品中铜含量为<0.02-0.37mg/L、在2个样品中探测到银含量的最大值为0.021mg/L。钴含量为<0.04-0.22mg/L,钼为<0.03—0.05mg/L。均未发现金,铂和钯的含量超过用石墨炉原子吸收方法测量的分别为0.000lmg/L、0.003mg/L和0.002mg/L的低探测限。这次研究结果与最近公布的微量金属在富氯化物热液中的溶解度比较表明卤水相对于铅、锌和铁近似饱和,显然,相对于金、铂、钯、锑、钴和可能银是未饱和的。被还原的硫含量、卤水的物理化学特性(如盐度、温度、氧化还原状态和pH值)、岩层金属源及卤水迁移过程的共同作用,明显控制着当前密西西比油田卤水里的微量金属浓度。
In the central part of Mississippi, several types of sedimentary rock-hosted metal deposits. The discovery of the local presence of significant geochemical trace metals in the brine of the lead and zinc-rich formations at the very bottom of the Cretaceous stratigraphy further confirms the causal relationship between sedimentary interlayer water and these deposits. The copper content in the brine samples of the Early Cretaceous strata was <0.02-0.37 mg / L, and the maximum silver content was found to be 0.021 mg / L in the two samples. The cobalt content is <0.04-0.22 mg / L, the molybdenum is <0.03-0.05 mg / L. None of the gold, platinum and palladium levels were found to exceed the low detection limits of 0.0001 mg / L, 0.003 mg / L and 0.002 mg / L, respectively, as measured by graphite furnace atomic absorption spectroscopy. The comparison of this study with the recently published solubility of trace metals in chloride-rich hydrothermal fluids shows that the brine is approximately saturated with respect to lead, zinc and iron, and obviously, relative to gold, platinum, palladium, antimony, cobalt, and possibly silver are not Saturated. The reduced sulfur content, the physicochemical properties (such as salinity, temperature, redox state and pH) of the brine, the interaction between the metal source in the formation and the brine migration significantly control the concentration of trace metals present in the brine of the Mississippi field.