新疆彩华沟与钼矿有关的岩浆岩地球化学特征研究

发布时间：2018-05-03 00:45

本文选题：中天山南缘 + 地球化学特征　；参考：《新疆大学》2015年硕士论文

【摘要】：中天山地块位于天山山脉中部,经过前人的研究,一般认为中天山是一个位于准噶尔板块与塔里木板块之间的一个微陆块,该陆块总体呈一西部较略宽,向东逐渐变窄的楔形,经过库米什,向东逐渐尖灭。在板块相互作用下,自晚古生带开始,南天山洋盆开始向北俯冲于中天山地块之下,致使中天山南缘形成了一系列与俯冲一碰撞有关的基性、超基性-中性-酸性的火山岩及侵入岩,并影响了本区晚古生带以来不同类型矿床的产出。彩华沟钼矿即产于中天山微陆块南缘NWW向花岗岩带上。本文行文前充分收集了前人资料并进行了详尽的野外地质工作,以新疆托克逊县库米什地区区域地质背景、构造演化及与钼矿有关的岩浆岩的地球化学特征为基础,详细研究了彩华沟钼矿的矿床地质特征、矿体地质特征、岩浆岩地球化学特征,并初步总结了矿床的成矿模式,最后结合区域地质背景、区域地质构造及区域地质演化规律及斑岩型钼矿的成矿条件及规律等方面的分析,对库米什地区钼矿化远景作出推断。库米什自晚古生带开始依次经历了弧后扩张-俯冲-碰撞-后期拉张回返四个时期的地质运动,构成了一个各阶段发育比较全面的威尔逊旋回,后期受走滑构造作用形成拉分盆地。其中南天山洋盆向北俯冲斜插到中天山地块之下及其与之碰撞阶段为本区各类岩浆岩的主要活动阶段,也是本区的主要成矿阶段,板块间的俯冲碰撞及岩浆岩的二次蒸腾作用控制了区内铜铅锌多金属矿床、钨矿、钼矿等矿床的形成。彩华沟二云母二长花岗斑岩与钼矿化关系密切,陈超等在研究忠宝钨矿时利用锆石U-Pb法获得其侵入年龄为298士3.2Ma,属晚石炭世。地球化学特征表明忠宝二云母二长花岗岩为具有中等-高的分异演化程度的高钾钙碱性过铝质花岗岩,为形成于同碰撞环境的壳源重熔S型花岗岩,源岩为中天山前寒武系基底。岩体中钼元素主要来自熔融之后的岩浆及二次蒸腾时流体对围岩的萃取。野外观察及室内研究表明,彩华沟钼矿床为斑岩型钼矿床,并伴有云英岩化、黄铁矿化、硅化及钾化。钼矿产于花岗斑岩内,矿体产出于库米什背斜东部倾伏端深部的花岗斑岩内,背斜转折端及两翼形成许多次级小褶皱,相邻岩层相对滑动致使褶皱的枢纽及两翼部分常形成层状、似层状、马鞍状剥离空洞,有利于岩体进入围岩进行矽卡岩交代。这就是其上部形成矽卡岩型钨矿床的原因。背斜南翼地层受NE向断裂破坏从而为岩浆侵入提供了通道及侵入空间,后期近SN向断裂构造多为对矿体的后期改造,由于彩华沟钼矿床埋藏较深及开展的地质工作有限,彩华沟钼矿床是否收到上述地质条件影响尚不明确。矿石矿物组分与结构构造:矿石中矿石矿物主要为黄铁矿、辉钼矿、次为黄铜矿、少量方铅矿、磁黄铁矿、白钨矿、孔雀石。脉石矿物主要为黑云母、白云母、石英、斜长石、钾长石、钠长石等。岩石结构主要为斑状、似斑状结构、块状构造。成矿作用按先后顺序可划分为钾长石-氧化物-硫化物期、云英岩-硫化物期、青磐岩-氧化物期。其中钾长石-氧化物-硫化物期及云英岩-硫化物期为主要的成矿阶段。
[Abstract]:The Middle Tianshan massif is located in the middle of the Tianshan Mountains. Through previous studies, it is generally believed that the Middle Tianshan Mountain is a micro block between the Junggar plate and the Tarim plate. The block, which is slightly wider in the west, narrowed to the East, gradually narrowed into the East, and gradually pointed out eastward through Kumish. In the beginning, the South Tianshan ocean basin began to subduction to the Middle Tianshan massif, causing a series of subduction related basic, ultrabasic acid volcanic rocks and intrusive rocks in the southern margin of the Middle Tianshan Mountains, and affecting the output of different types of deposits since the late Paleozoic zone in this area. The color Hua Gou molybdenum mine was produced in the southern margin of the Middle Tianshan micro block NWW. In this paper, we have fully collected the previous data and carried out a detailed field geological work. Based on the regional geological background, tectonic evolution and the geochemical characteristics of the magmite related to molybdenum ore, the geological features and geological features of the orebody are studied in detail. The geochemical characteristics of magmatic rocks are made and the metallogenic model of the deposit is preliminarily summarized. Finally, based on the analysis of regional geological background, regional geological structure and regional geological evolution and the metallogenic conditions and laws of porphyry molybdenum ore, the prospect of molybdenum mineralization in Kumish area is inferred. Kumish has been in turn from the beginning of the late Paleozoic zone. The geological movement of four periods of post arc expansion - subduction - collision - later extension and return, formed a relatively comprehensive Wilson cycle in each stage, and later subjected to a strike slip structure to form a pull apart basin. At the stage of activity, it is also the main metallogenic stage in this area. The subduction collision between plates and two transpiration of magmatic rocks control the formation of copper lead zinc polymetallic deposit, tungsten ore, molybdenum ore and so on. The two mica two long granite porphyry in color Hua Gou is closely related to molybdenum mineralization. Chen superclass is obtained by using zircon U-Pb method in the study of Zhong Bao tungsten ore. Its invasion age is 298 3.2Ma and belongs to the Late Carboniferous. The geochemical characteristics indicate that Zhongbao two mica two granites are high potassium calcium alkaline peraluminous granites with moderate to high differentiation and evolution degree, which are formed in the crust source remelting S type granite in the same collision environment, and the source rocks are the basement of the Cambrian in the middle of the central mountain. Molybdenum elements are mainly in the rock mass. The extraction of the magma after melting and the extraction of the fluid to the surrounding rock during the two transpiration. Field observation and laboratory studies show that the color Hua Gou molybdenum deposit is a porphyry molybdenum deposit, accompanied by cloud and quartz, pyrite mineralization, silicification and potassium. The molybdenum ore occurs in the granite porphyry, and the ore body is produced in the granite porphyry in the deep dipping end of the Kumish anticline, and the anticline turns. The folding end and the two wings formed a number of secondary small folds, and the adjacent strata relative sliding resulted in the formation of the pivot and the two wings of the folds, such as lamellar, saddle like peeling holes, favorable for the rock mass entering the surrounding rock and metasomatism of skarn rocks. This is the cause of the formation of a skarn tungsten deposit in the upper part of the anticline. The south wing of the anticline is damaged by the NE fault. For the intrusion of magma, the passage and intruding space are provided, and the late SN trending fault structure is mostly the later transformation of the ore body. Because of the deep buried and limited geological work in the color Hua Gou molybdenum deposit, it is not clear whether the color of the color Hua Gou molybdenum deposit has been affected by the above geological conditions. Ore mineral composition and structural structure: ore minerals are the main ore minerals. Pyrite, molybdenite, secondary chalcopyrite, a small amount of galena, pyrrhotite, scheelite, and malachite. The gangue minerals are mainly black mica, muscovite, quartz, plagioclase, potassium feldspar, and albite. The rock structure is mainly porphyritic, porphyritic and massive, which can be divided into potash feldspar oxide sulfide phase in sequence. The Yunnan Yunnan sulfide period, the blupan rock oxide stage, is the main metallogenic stage of potash feldspar oxide sulphide period and cloud rock sulfide period.

【学位授予单位】：新疆大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.65;P588.1

【参考文献】