摘要
秦岭凤太矿田层控铅锌(铜)矿床的金属物质、硫和成矿溶液主要来自深部基底的岩石,属海底喷流—沉积成因矿床。从这一理论认识出发可进一步分析控矿地质条件及今后在该区有效地寻找同类矿床。
At first, the mineralized materials of the stratabound Pb-Zn ore deposits of the Fengtai ore field in the Qinling Mountain were considered to have originated from the magmatic hydrothermal solution, and after this, many people tended to think they were from the weathering denudation of the old continental rocks on the both sides of the Qinling trench, in this article a large number of facts show that the materials mainly stemmed from the deep strata and rocks through which the hot groundwater is infiltrated. The compositions of the ore lead isotope, in every ore deposit are all stable and the characteristic value of the source area is high. This shows that the source of the ore lead is the same as that of the present sea-floor sediments. According to the Doe methord, the single-stage model ages calculated ore lead-isotopes of the mainly between 390-450 my. and the age older than that of the middle Devonian-period stratum with ore also hints that the lead was possibly from the basement strata. In the terms of the chemical elements of the ores and the wall rock, Si02, Hg, Mn and so on of the ore, the typical hydrothermal elements, are obviously higher in the ores than in the wall rocks, and the difference between Co/Ni and Sr/Ba is very great.The trace element features of the metalliferous sulphide are different from those of the normal marine deposits and the magnatic hydrothermal solutions. And the main ore-holding rocks-silicolites are neither the products of the volcanic exhalation, nor the products of the marine deposits, but their features are similar to those of the sea-floor exhalogene. In addition, the background contents of the mineralized elements in the Devonian ore-bearing strata are low, and they have no any significance of ore sources. The facts mentioned above fully show that the metallic materials didn't stem from the old continental rocks, but they most possibly came from the extraction by the hydrothermal solutions in the deep strata.
The features of the sulphur isotope compositions in m
关键词
铅锌矿床
成矿物质
层控
矿床
Fengtai ore field
minerogenetic material source
syngenetic hydrothermal solution
sea-floor exhalation
sedimentary meneral deposit
