新疆哈密东戈壁超大型钼矿床成矿热液蚀变作用分析

ORE-FORMING HYDROTHERMAL SOLUTION ALTERATION ANALYSIS FOR DONGGEBI OVERSIZE MOLYBDENUM ORE DEPOSIT OF XINJIANG HAMI

我国天山山脉东段(新疆哈密)东戈壁超大型斑岩型钼矿床,其成矿热液蚀变作用主要表现形式为各种脉体的大量产出,主要类型有:1.硅化:①出现数以万计的大量脉体;②硅化带;2.钾长石化:大量的含钾长石的脉体,其中石英-钾长石脉及钾长石-石英脉最多;3.碳酸盐化:为成矿后期热液活动的产物,成矿阶段较少;4.萤石化:一般与其他组分的脉体形成复式脉,如萤石-石英脉、萤石-钾长石脉等。上述4种蚀变类型以硅化与成矿关系最为密切。其次为钾长石化。可以说石英脉及钾长石脉即为钼金属元素热液活动中的主要载体;而碳酸盐盐化与萤石化则不是主要成矿热液蚀变类型;矿床的蚀变分带共4带,由内到外为:1.白云母石化带(绢英岩化带);2.钾化带;3.硅化带;4.黑云母化带。除白云母化带界线清楚外,其余三个带相互渐变过渡。总而言之,矿床成矿热液蚀变作用的区域与矿区主要工业矿体的分布区相一致。

Donggebi oversize porphyry molybdenum deposit is located in mountain Tianshan ridge in Hami,Xinjiang province.The main form of its ore-forming hydrothermal solution alteration is the appearance of a large number of all kinds of vein bodies,the main types： 1.silicification：（1） appearing tens of thousands of large veins bodies;（2） silicified belt;2.potash feldspathization： a large number of vein bodies containing potassium feldspar,with most quartz-potassium feldspar vein and potassium feldspar-quartz vein;3.carbonatization： it is the product of ore-forming later stage hydrothermal activity,less in ore-forming stage;4.fluoritization： general with other components vein body form double vein,such as fluorite-quartz vein,fluorite-potassium feldspar vein,etc.According to silicification most closely related to ore forming in the above four alteration types.secondly is potash feldspathization.So to speak ＂quartz vein and potassium feldspar vein that are the main carrier in the molybdenum metal elements hydrothermal activity,and that carbonatization and fluoritization is not main ore-forming hydrothermal alteration types.Ore deposit alteration divide 4 belt,by inside to outside is： 1.Muscovitization belt（Sericite quartzitization belt）;2.Potash feldspathization belt;3.silicified belt;4.Biotitization.Divide Muscovitization belt has clear boundary line,the others three belt mutual gradual transition.In a word,the area of ore deposit ore-forming hydrothermal alteration with major industrial orebody distribute of mining district is consistent.