【作者】 辛存林；

【导师】 孙柏年；

【作者基本信息】 兰州大学 ， 古生物与地层学， 2009， 博士

【摘要】 新疆西准噶尔萨吾尔山—沙尔布尔提山形成和隆起与后碰撞岩浆活动有着密切的联系。研究该区的岩浆侵入活动和火山喷出活动对进一步探讨西准噶尔萨吾尔山扎合—沙尔布尔提山欧勒地区金、铜多金属成矿作用有着非常重要的理论意义。开展西准噶尔金、铜多金属成矿作用的研究，有利于深入探讨该区火山—侵入岩地球化学特征、形成年代和金铜成矿作用机理。深入研究西准噶尔萨吾尔扎合—沙尔布尔提欧勒地区金、铜多金属成矿作用与成矿潜力，对于解决国内金、铜矿产品需求量快速增长，原料短缺的矛盾具有重要的现实意义，同时，为开发利用该区的矿产资源提供了有用的参数。本文以扎合—欧勒地区为研究对象，在前人区域研究成果的基础上，运用岩石学、构造地质学、矿床学、放射性Rs-Sr同位素测年和示踪，主量、微量、稀土元素，论证了扎合岩体的成岩时代、构造环境及其岩体与金矿化的关系问题。通过对扎合金矿和欧勒铜矿的分析研究，深入开展了其成矿地质背景、地质矿化特征、地球化学特征、成岩时代和成因机制等一系列科学问题的研究，进而探讨了该地区地球演化、地球动力学背景、找矿标志；并对该区的成矿潜力进行了评价。论文主要取得了以下进展：1、扎合岩体地质特征、地球化学特征的研究岩体边部是较富铁镁质的角闪辉长岩、辉绿岩，向岩体的中心，过渡为富长英质的闪长岩、花岗闪长岩、花岗斑岩。岩体呈不规则状岩枝或岩脉侵入于下石炭统黑山头组（C₁h）地层中。岩体的主要矿物成分为蚀变斜长石、普通角闪石、石英、黑云母、绢云母、辉石、绿泥石等；次要矿物为榍石、磷灰石、磁铁矿、褐铁矿和黄铁矿等。近矿部位有不同程度的交代蚀变、硅化及褐铁矿化、绢云母化。扎合岩体SiO₂含量变化范围较大，具钙碱性特点。岩石富Na₂O，贫K₂O，具高Na₂O／K₂O的特点。分异指数较低，固结指数较高，反映其分离结晶的程度不高，分异较差，岩浆分异、演化不彻底。扎合岩体的(⁸⁷Sr／⁸⁶Sr)_i值平均为0.70433（0.704000～0.704895），其成岩物质应起源于地幔。利用岩浆岩的化学成分，可估算岩浆岩的结晶温度为1120～1250℃，岩浆岩的结晶深度为13.2～15.8km。扎合岩体形成的构造背景为后碰撞阶段的挤压环境，即大陆火山弧地区。测年结果显示，扎合岩体的Rb-Sr等时线年龄为246±13 Ma，因此，西准噶尔萨吾尔地区扎合岩体侵位时代为晚二叠世末-早三叠世初。2、扎合金矿的地质特征及成矿作用的系统研究对矿区地层、构造、岩浆岩、地球化学特征及含矿构造蚀变带进行了较为详细的研究，大致查明矿化体赋存规律，对矿床成因有了一定认识。通过野外地质调查共圈定出金矿带（脉）4条，主要位于矿区扎合哈尔盖图山沟东测岩体内及岩体与砂岩接触带；矿带走向为105-130°，倾向15-35°，倾角50-60°；矿带宽约0.8-2m，向两侧逐渐变窄，长度约65-150m；矿体金品位一般为1～4×10^-6，最高可达约13.89×10^-6。远离岩体的部位，金矿化不明显。矿石的工业类型为碎裂岩化蚀变岩型金矿石。3、欧勒铜矿的地质特征及成矿作用的详细研究对矿区地层、构造、岩浆岩、地球化学特征及含矿构造蚀变带进行了较为详细的研究，基本（大致）查明矿化赋存规律，对矿床成因有了一定认识。通过野外地质调查共圈定铜矿化带9条，走向近东西向，长度10-20m，品位0.2％-0.48％。共圈定含铜葡萄石脉23条，走向近东西向，长度5-40m，宽度0.1-1.2m，品位0.06％-0.43％。大致查明了矿体规模、形态、产状及空间变化特点；初步查明了矿体的连续性较差。4、扎合—欧勒地区金、铜多金属成矿潜力的评价通过对扎合—欧勒地区的区地质域背景、成矿物质、构造条件、成矿热液、围岩蚀变、岩体与金铜成矿的关系等方面的系统分析，认为扎合地区具有较好的金成矿潜力，矿体在深部有变大、变好的可能。欧勒铜矿的铜成矿潜力有待于进一步研究。更多还原

【Abstract】 There is the close relation between the form、uplift and the post-coilisional magmatic activity ofSawuer-Sabuerti Mountains. It is important to study the magma intrusion activity and volcanic activityfor further discussion of the mineralization of the Zhahe-Oule Au-Cu deposit in Western Junggar, and itis also propitious to discuss the intrusive rock and volcanic rock’s geochemistrical character, age and theformation mechanism of Au-Cu deposit, when we study the mineralization of Western Jungga Au-Cupolymetallic deposit. So, there is a very imprtant practical significance to resolve the conflict betweenthe Au-Cu deposit product requirement’s rising and the raw materials’ scarcities, at the same time, weprovided a useful parameter for the development and utilization of mineral resources in the area.In order to research the age of the Zhahe pluton, its tectonic settings and the relation betweenZhahe pluton and Au deposit, author applied multidisciplinary methods, such as petrology, tectonics,deposit, Rb-Sr dating, the major elements, trace elements and so on, in this paper.By the study of geological setting, mineralization character, geochemical character, metallogenicgeological condition, pluton’s age and deposit formation mechanism, the author ascertained the area’searth evolvement, geodynamical setting, prospecting indication, and evaluted mineralization potential.Through the above studys, some conclusions can be drawn as follow:1.Geological and geochemical characteristicThe pluton distributes like zonation, the border is the hornblende gabbros and diabase; from theborder to the center, the rock changes gradually, from diorite, granodiorite to Granite porphyry. Theyintruded into Heishantou formation stratum, Lower Carboniferous. The primary minerals of the plutonare metamorphic plagioclase, hornblende, quartz, biotite, sericite, picrite and chlorite; secondaryminerals are sphene, apatite, magnetite, limonite and pyrite; and the alterations are metasomaticalteration, silicide alteration, limonite alteration and sericitization.Zhahe pluton has a wide range of SiO₂ content, a calc-alkaline characteristic, it is rich in Na₂O,poor in K₂O, and has a high value of Na₂O/K₂O. The rock has a low DI, high CI, theyreflect a low fractional crystallization degree, the magmatic differentiation and evolution are notcompleted, also.The average value of （87Sr/86Sr）_i is 0.70433 （0.704000～0.704895）, the diagenetic material shouldbe originated in the mantle. Using the chemical composition of the igneous rocks, the temperature ofcrystallization can be estimated that is 1120～1250℃, depth of the magmatic rocks’ crystallization is13.2～15.8km. The pluton formed in a extrusion setting, the post-collision tectonic stage, in other words,that is volcanic arc areas of the mainland. The Rb-Sr isochron age of the pluton is 246±13Ma, so it isshowed that the incursion time of Zhahe pluton in West Junggar is Changhsinggian to Induan.2. Geological characteristic and mineralization of Zhahe gold deposit Based on the detailedly study of statum, structure, magmatic rocks, geochemical characteristicsand orebearing alteration structure in this diggings, the author identified the deoposit rules and hadsome ideas on the genesis of ore deposits.Through the geological survey, the author found four gold mineralization zone, in the mining area,located mainly in the contact zone of pluton east Zhahe Haergantu valley and sandstone, nearly105-130°direction, 50-60°obliquity, 0.8-2m width, 65-150m length, average grade of 1～4×10^-6, themost highest value is 13.89×10^-6. The An mineralization is not obvious far away from the pluton, andthe ore’s industrial type is the fragments of the altered rock-type gold ore.3. Mineralization potential evaluation of Oule Au-Cu depositBased on the detailedly study of statum, structure, magmatic rocks, geochemical characteristicsand orebearing alteration structure in this diggings, the author identified the deoposit rules and hadsome ideas on the genesis of ore deposits.Through the geological survey, the author found nine copper mineralization zone, nearly east-westdirection, the length of 10-20m, grade of 0.2%-0.48%. And found out the deposit’s scale, modality,occurrence and continuity.4. Mineralization potential evaluation on Zhahe-Oule Au-Cu Polymetallic depositIt is showed that there is a good Au mineralization potential and it is possible that the Au depositbodies should be big and mineralization should be better than the earth’s surface. By the analysis ofregional background, mineralization minerals, tectonic conditions, hydrothermal mineralization,wall-rock alteration, the relation of pluton and Au-Cu deposit. But the potential of Oule Cu deposit maybe needed further studied.更多还原