The Existing Status Study Of Silver Of Xiabao Deposit In Lengshuikeng Silver-lead-zinc Ore Field, Jiangxi Province

Jiangxi nengshuiken Ag-Pb-Zn polymetallic ore field is an important Ag-Pb-Zn fields, with the unique characteristics of the mineralization:not only the upper part of porphyry type deposits, but also the lower part of the insidious volcanic deposition-hydrothermal alteration type (layer control)deposits. On the basis of field observes, draw the selected highway sections focus on output under xiabao volcanic deposition-hydrothermal alteration-type deposits A7orebody ore. Indoor microscopy, scanning electron microscope, electronic probe and laser ablation inductively coupled plasma massspectrometry (LA-ICP-MS) and other instruments, the occurrence characteristics of the deposit of silver minerals, chemical compositions and more in-depth study, at the same time the formation of silver mineral in the area hydrothermal mineralization conditions, provide the basis for the study under xiabao mining area silver Causes of Ag-Pb-Zn deposits and metallogenic mechanism. The results show that:(1) nengshuikeng xiabao mine silver mainly occurs in the form of microscopic visible independent mineral phase, silver elements are mainly the formation of a sulfur-rich system of epithermal silver minerals, native silver and spiral-shaped sulfur-based silver mine, silver tetrahedrite, followed with a small amount of silver gold, crimson silver mines, sulfur silver tin. The order which the minerals formed is freibergite�'electrum�'pyrargyrite�'canfieldite�'natural silver.(2) microscopy silver in xiabao mining area is unvisible silver mineral and crystal lattice in the metal sulfide mineral galena-sphalerite-chalcopyrite-pyrite silver contents161.1g/T130.8g/T,63.8g/T,23.0g/T.Compared to domestic other volcanodeposition-hydrothermal transformation deposit, its content is lower by an order of magnitude. The possible causes may be due to in the ore-forming fluid system the lack of Sb3+、Bi3+two kinds of cation, lead to the silver ions can not be easy to maintain charge balance in the lattice of galena, sphalerite and other minerals, in the silver mines of the final stage of discharge related to the lattice of the above minerals.(3)Xiabao Ag-Pb-Zn deposit causes of late by volcanic sedimentary ore-forming hydrothermal fill superimposed mineralization. Iron and manganese carbonate ore is also very high silver content of ore, rich quality of iron and manganese on the activation of the silver ions in the hydrothermal fluids and precipitation good role, showing porphyry ore-forming fluids during ascent and early volcanic sedimentary iron and manganese carbonate layer and its layer broken the interaction between the band.(4) nengshuikeng xiabao deposit of silver element in the fluid migration, enrichment, sedimentation processes is closely related to the thermodynamic properties of silver, lead, zinc. Ore-forming fluids from high to low temperature, the pH from acidic to weakly acidic, changes in oxygen fugacity from high to low played key role of guidance and control in formation of silver minerals.