内蒙古浩尧尔忽洞金矿矿床地球化学特征与成因研究

发布时间：2018-03-28 04:22

  本文选题：浩尧尔忽洞金矿　切入点：黑色岩系　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：内蒙古浩尧尔忽洞金矿,又名长山壕金矿,位于巴彦淖尔市乌拉特中旗新忽热苏木东北约10km处,大地构造位置处于华北陆块北缘狼山-白云鄂博裂谷带。矿床赋矿地层为白云鄂博群比鲁特组,累计探明储量148.5t,平均品位0.82g/t,是我国北方最大的堆浸金矿山,具有规模大、品位低、易开采的特点。矿区内1:200地质地球化学剖面调查发现,Au元素品位与黄铁矿脉、石英-黄铁矿脉的发育程度呈明显正相关,矿区内各类侵入岩体(脉)本身含金量不高,金物质来源不太可能由岩浆活动提供,但是侵入岩体脉周围地层的Au含量有不同程度的升高,表明后期岩浆事件对金矿化有一定富集作用。分析表明,载金黄铁矿轻重稀土分异程度比较高,稀土配分曲线右倾,具Eu的负异常和Ce的弱负异常或无异常,与碳质地层、矿区外围地层的配分曲线和特征值相似,而与区内岩浆岩有所区别,说明成矿物质应该主要来源于地层。黄铁矿硫同位素结果显示δ34S的值集中在11.2‰-14.7‰,均值13.15‰,显示浩尧尔忽洞金矿是单一硫源,而黄铁矿微量元素Co/Ni比值1,Y/Ho比值与碳质浅变质岩相近,推断成矿流体为变质流体,成矿物质应主要来自于碳质地层。碳质地层样品的Sr/Ba比值为0.036~0.702,平均值为0.198,指示含矿碳质地层主要为陆源沉积。矿床有机地球化学研究结果表明,地层有机碳含量与Au元素一定程度负相关,说明Au的沉淀应该与有机质的热解有一定关系。正构烷烃的碳数分布范围为C11-C38,主要分布于C16-C27,主峰碳为C16和C18,表明研究区有机质应主要来源于菌藻类,(nC21+nC22)/(nC28+nC29)比值范围0.74~3.10,均值1.81,指示海相有机质输入;Pr/Ph范围为0.51~0.84,均值为0.67,指示矿源层形成于盐度正常的缺氧、还原沉积环境中。而铂族元素中Ir的含量最高,均值为3.19×10-9,与原始地幔(3.2×10-9,McDonough et al,1995)非常接近,暗示Ir可能来源于地幔。Pd含量与金元素含量呈现一定的正相关(r=0.7970),而Ir与Au的相关性不明显(r=-0.3221)。总结浩尧尔忽洞金矿成矿模式为:(1)中元古代白云鄂博群沉积,在缺氧还原环境中,预富集形成了最初的富硫、铁、金和有机质的矿源层,主要证据是地层中广泛发育的星点状、针尖状黄铁矿和碳质成分;(2)新元古代到石炭纪晚期,同步于区域构造作用发生褶皱变形的石英-黄铁矿脉和黄铁矿脉,表明该时期初步富集形成了含矿建造和矿胚;(3)海西期岩浆侵入,使地层中的预富集金发生了活化迁移,加富了有利地段局部金矿的品位。
[Abstract]:Inner Mongolia Haoyaoer and hole gold, also known as changshanhao gold deposit, located in Bayannaoer City, Wulatezhongqi Xinhure hematoxylin northeast at about 10km, tectonically located in the northern margin of the North China Craton Langshan Baiyunebo rift zone. Ore deposits and ore formation is the Baiyunebo group bierut total proven reserves of group 148.5t, the average grade of 0.82g/t, is the largest heap leaching of gold mines in northern China, with a large scale, low grade, easy mining. 1:200 geological geochemical profile survey found within the mining area, Au grade and pyrite veins, showed a positive correlation with the degree of development of quartz pyrite veins, various types of intrusive rocks within the mining area (vein) itself is not high gold content, gold source material not too may be provided by magmatic activity, but the content of Au invasion formation around the rock veins increased in different degree, indicating that the late magmatic events have a certain effect on the enrichment of gold mineralization. The results show that, Bearing pyrite REE fractionation degree is relatively high, REE patterns, negative anomaly and weak negative Ce Eu anomaly or no anomaly, and carbonaceous strata, the periphery of the mining strata distribution curve and the characteristic value of similar and different and magmatite zone, indicating that the matter should be the main source of minerals in the formation. Pyrite sulfur isotope indicates the delta 34S values from 11.2 -14.7%%, average 13.15 per thousand, Haoyaoer display hole suddenly gold deposit is a single sulfur source, and trace elements in pyrite Co/Ni ratio 1, Y/Ho ratio and carbonaceous shallow metamorphic rock is similar to that inferred mineralization fluid of metamorphic fluid, metallogenic material should be mainly from the carbonaceous strata Sr/Ba. The ratio of carbonaceous formation sample was 0.036~0.702, the average value is 0.198, indicating the ore carbonaceous strata are mainly terrigenous sedimentary deposits. Organic geochemical study shows that organic carbon content of the formation and Au elements to a certain extent Negative correlation, indicating that Au should have a certain relationship with the precipitation of pyrolysis of organic matter. The carbon number range of alkanes is C11-C38, mainly in C16-C27, C16 and C18 as the main peak carbon. The results showed that the organic matter in study area should be mainly derived from bacteria and algae, (nC21+nC22) / (nC28+nC29) ratio range of 0.74~3.10. The mean value of 1.81, indicating the marine organic matter input; the Pr/Ph range is 0.51~0.84, the average is 0.67, indicating the ore source layer formed in anoxic normal salinity, reducing sedimentary environment. While the content of platinum group elements in Ir is the highest, the average is 3.19 * 10-9, and the primitive mantle (3.2 x 10-9 McDonough, et al, 1995) very close, suggesting that Ir may be derived from the mantle.Pd content and metal element content showed a positive correlation (r=0.7970), and the correlation between Ir and Au was not significant (r=-0.3221). Hojaur summed up the hole suddenly gold metallogenic model: (1) the Mesoproterozoic Baiyunebo group deposition, reducing ring in hypoxia In the environment, pre enrichment form of sulfur rich, the first iron ore source layer, gold and organic matter, the main evidence is widely developed in the formation of star shaped, needle like pyrite and carbonaceous composition; (2) late Proterozoic to late Carboniferous, synchronized with the regional tectonic action fold deformation of quartz pyrite veins and pyrite veins, showed that the period of preliminary enrichment of ore formation and ore formation of the embryo; (3) the Hercynian magmatic intrusion, the formation of pre enrichment of gold occurred in the activation and migration with rich local gold favorable area taste.

【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P618.51
，

本文编号：1674737