云南易门铜厂矿区主含矿层沉积特征和成矿关系研究

发布时间：2018-04-27 05:27

本文选题：易门铜厂 + 中昆阳群　；参考：《昆明理工大学》2015年硕士论文

【摘要】：云南易门铜矿带是滇中地区重要的铜资源矿区,铜厂矿区属易门东矿带的重要矿床之一。本文依托“易门铜厂及外围铜矿成矿规律与找矿预测研究项目”进行选题。通过野外地质调查,铜厂矿区沉积—成岩成矿特征明显,选取铜厂矿区中昆阳群落雪组地层(主含矿层)为研究对象。从含矿层地层厚度的时空变化、沉积构造、岩石组合、沉积微相特征、岩石地球化学特征等方面的研究,得出了矿区古沉积环境特征,并总结了沉积相模式,最终阐明了沉积环境与沉积成岩型矿体的关系。取得的认识有：1、对云南省易门铜厂矿区中昆阳群落雪组地层做了空间及时间上的对比研究,发现沿NE-SW方向上铜厂矿区古沉积盆地存在“两凹夹一隆”构造格局,且NE侧(17线以北)含矿性较好,SW侧(23线以南)含矿性差,矿化较弱。2、参照八十年代Flugel和Wilson的碳酸盐岩基本相模型和微相类型,并且依据野外现场调查和室内薄片鉴定,把落雪组白云岩分为八个微相类型,分别为MF1微晶—粉晶白云岩、MF2纹层状白云岩、MF3鲕状白云岩、MF4藻屑白云岩、MF5碎屑白云岩、MF6硅质白云岩、MF7硅化白云岩、MF8泥质白云岩。3、本文对研究区主含矿层白云岩主量元素、微量元素、稀土元素的沉积地球化学特征的研究表明：①不同岩石类型化学成分不同,与岩石岩性关系密切。总体上看落雪组一段(Pt2l1)白云岩SiO2+Al2O3平均值高,显著富含陆源物质(泥质),属高杂质白云岩类。落雪组二段(Pt2l2)白云岩普遍含硅质条带或硅质团块,CaO+MgO平均值高,Al2O3低,SiO2高,属硅质白云岩类。落雪组三段(Pt2l3)白云岩成分与落雪组二段总体相似。主要含矿层落雪组二段(Pt2l2)中的Cu、Co、Ba、 Zn、Sb平均含量相对落雪组一、三段(Pt2l1,Pt2l3)较高,这与矿化有关。不同岩石类型样品稀土元素配分模式都具有明显右倾趋势,轻稀土富集,重稀土相对亏损。落雪组二段δEu平均值为0.78,显示轻微-中等负Eu异常,反映整个地层沉积环境偏还原性,矿区北部Eu异常较为明显。②沉积地球化学指标[Sr/Ba、B/Ga、m、V/(V+Ni)、Fe2+/Fe3+、Mg/Ca、 Sr/Cu]反映,落雪组沉积期沉积环境经历了弱还原(Pt2l1)→还原(Pt2l2)→弱还原(Pt2l3)和近岸-海水环境(Pt2l1)→半咸水(Pt2l2-Pt2l3)的演化过程。在空间上,落雪组第二段沉积期,北部潮坪洼地具高盐度(Sr/Ba=0.540,B/Ga=4.011)和还原性强(Fe2+/Fe3+=14.706)等标志,南部潮坪洼地具中盐度(Sr/Ba=0.25, B/Ga=2.6)和还原性较弱(Fe2+/Fe3+=2.54)特征。4、含矿层沉积相标志研究表明,中部隆起(潮坪礁滩相)锥状、球状、柱状叠层石发育,可见波状层理、透镜状层理构造和冲刷构造,水动力较强。南部和北部潮坪洼地层状或不规则条带状叠层石发育。北部潮坪洼地相可见纹层状构造、包卷层理、斜层理、波状层理、冲刷构造、扰动构造等,水动力强-较强。南部潮坪洼地相常见纹层状构造,水动力较强-较弱。5、宏观地质、岩石地球化学及沉积相研究表明,矿区沉积成岩型矿化在很大程度上受控于岩相古地理环境,17线以北的潮坪洼地相为相对封闭的低能带,海水盐度较高、处于相对还原环境,利于成矿物质聚集,沉积成岩型矿体发育较好,是主要成矿地段。23线以南的潮坪洼地与外海沟通较好,封闭性较差,海水盐度中等,处于弱还原环境,不利于成矿物质聚集。
[Abstract]:The Yunnan Yimen copper mine belt is an important copper resource mining area in Central Yunnan, and copper factory mining area is one of the most important ore deposits in the Yimen east ore belt. This article is based on the "Yimen copper plant and the peripheral copper ore metallogenic law and prospecting prediction research project". In the middle Kunyang community, the snow formation (main ore bearing layer) is the research object. From the temporal and spatial variation of the thickness of the stratum, the sedimentary structure, rock assemblage, the characteristics of sedimentary microfacies and the geochemical characteristics of the rock, the characteristics of the paleosedimentary environment of the mining area are obtained, and the sedimentary facies model is summarized, and the sedimentary environment and sedimentary rock type ore are finally clarified. The understanding of the body is as follows: 1, a comparative study was made on the space and time of the Kunyang community snow formation in the Yunnan Yimen copper factory mining area. It was found that there was a structural pattern of "two concave clips one uplift" in the ancient sedimentary basin along the NE-SW direction, and the ore bearing property of the NE side (north of the 17 line) was better, and the mineralization was poor in the SW side (23 lines to the South), and mineralization was poor. Weak.2, referring to the basic facies model and microfacies type of the carbonate rock of Flugel and Wilson in 80s, and according to field investigation and laboratory examination, the snow formation dolomite is divided into eight microfacies types, which are MF1 microcrystalline dolomite, MF2 lamellar dolomite, MF3 oolitic dolomite, MF4 algal dolomite, MF5 detrital white cloud. Rock, MF6 siliceous dolomite, MF7 silicified dolomite and MF8 argillaceous dolomite.3. This paper studies the sedimentary geochemical characteristics of main elements, trace elements and rare earth elements of the main ore bearing dolomite in the study area: (1) the chemical composition of different rock types is different and closely related to rock lithology. In general, the snowrock group A (Pt2l1) dolomite SiO The average value of 2+Al2O3 is high, which is rich in terrestrial material (mud) and belongs to high impurity dolomite. The two (Pt2l2) dolomite of the snowfall group generally contains siliceous or siliceous masses, the average value of CaO+MgO is high, the Al2O3 is low, and the SiO2 is high, which belongs to the siliceous dolomite. The three segment of the snow formation (Pt2l3) is similar to the two segment of the snow group. The average content of Cu, Co, Ba, Zn, Sb in the two section (Pt2l2) is relatively high in one or three segments (Pt2l1, Pt2l3), which is related to mineralization. The distribution patterns of rare earth elements in different rock types have obvious right tendency, light rare-earth enrichment and relative loss of heavy rare earth. The two segment of the two segment of the falling snow group is 0.78, showing a mild medium negative Eu anomaly. The sedimentary environment of the whole stratum is partial reduction, and the Eu anomaly in the northern part of the mining area is more obvious. (2) the sedimentary geochemistry index [Sr/Ba, B/Ga, m, V/ (V+Ni), Fe2+/Fe3+, Mg/Ca, Sr/Cu] reflected, and the sedimentary environment of the snow formation period experienced the weak reduction (Pt2l1), reduction (Pt2l2), weak reduction (Pt2l3) and coastal seawater environment. Evolution process. In space, the sedimentary period of the second section of the snowfall group, the northern tidal flat has high salinity (Sr/Ba=0.540, B/Ga=4.011) and reducing strong (Fe2+/Fe3+=14.706) marks, the South tidal flat depression with the middle salinity (Sr/Ba=0.25, B/Ga=2.6) and the weaker (Fe2+/Fe3+ =2.54) characteristic.4, the sedimentary facies mark of the mineral layer shows that the middle uplift (tide) Taper reef beach facies, cone shaped, spherical and columnar stratified bedding, visible wave bedding, lenticular bedding structure and scour structure, strong hydrodynamic force. The stratiform or irregular stripe strate strate rocks are developed in the South and North tidal flat. The northern tidal flat is visible lamellar structure, coiling bedding, diagonal bedding, wave bedding, scour structure, disturbance structure, etc. The hydrodynamic force is strong. The common striate structure in the South tidal flat, the strong hydrodynamic - weak.5, the macroscopic geology, the rock geochemistry and sedimentary facies studies show that the sedimentary diagenetic mineralization of the mining area is largely controlled by the lithofacies palaeogeographic environment, and the tidal flat in the north of the 17 line is relatively closed low energy zone, and the salinity of the sea water is high. In the relative reduction environment, it is beneficial to the accumulation of minerals, and the sedimentary orebodies are well developed. It is better to communicate with the outside sea in the tidal flat of the main metallogenic section of the.23 line in the south. The sealing property is poor, the salinity of the sea water is medium, and it is in the weak reduction environment, which is not conducive to the accumulation of minerals.

【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.41

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