海南省千家地区钼铅锌矿成矿规律探讨

发布时间：2018-05-21 05:00

本文选题：钼铅锌 + 成矿地质背景　；参考：《成都理工大学》2015年硕士论文

【摘要】：千家地区位于海南岛西南部,处于陵水-九所深大断裂与白沙断陷相交处。近年来,随基础地质和小比例尺区域成矿规律研究的深入。海南岛西南部发现众多具有良好成矿前景的矿床(点)。它们的分布具一定的区域规律:①矿床(点)成因相似;②矿产多为钼、锡、金、铅、锌金属矿床(点);③矿床(点)分布与中生代岩浆-构造运动息息相关,多集中分布在岩浆岩体边缘或附近地层区中。千家地区在海南岛西南部区域成矿大环境影响下,矿床(点)类型及矿床成因与区域矿床类似;但亦显示出一些鲜明的特点:矿床(点)往往分布于岩体内。本文在前人研究成果的基础上,结合野外地质调查成果。综合利用岩石学、矿床学、地球化学、地球物理学、矿物学、同位素地质学及成矿规律与预测学等方法,探讨千家地区成矿规律。首先以区域地质背景为带入点,仔细了解区内地质情况。在此基础上仔细对比石门山钼铅锌矿、后万岭铅锌矿、看树岭银矿。初步发现三类矿床有一些共性:矿化与晚期斑岩侵入活动相关;矿床受南北、北西断裂构造控制明显,矿体围岩基本为花岗岩类;矿化与围岩蚀变程度呈正相关;矿石构造常见浸染状、细脉状、角砾充填状;矿床成因相关、成矿时间相近。这些共性极可能为成矿活动在研究区成矿地质背景限制下,形成的一系列成因相似、时空相关的不同元素组合矿床(点)。为此基于矿床(点)仔细观察,由点及面深入剖析研究区成矿地质条件,探讨区内成矿规律,形成以下认识:1.地层在区域上虽是重要成矿因素,但考虑到研究区内矿床(点)多分布在岩体内且地层分布极其有限。为此地层不做为成矿主因考虑。2.区内岩浆岩主要为花岗岩类岩浆多期侵入形成的千家岩体及晚期沿断裂侵入的斑岩。整个岩体符合华南地区含钼铅锌矿岩体的基本地质特征。岩体主微量元素显示千家岩体在成岩过程经历物化环境的变化,成岩后受强烈风化作用;在这背景下侵入的晚期斑岩既能分异含钼流体,还能驱动含矿流体在一定断裂张性空间内循环萃取铅锌成矿元素。3.南北-北西向断裂活动时间与斑岩侵入时间耦合,断裂张性空间为斑岩侵入和热液成矿提供空间,同时断裂的多期性使断裂带内易形成一个半封闭系统有利于钼、铅、锌富集沉淀。4.岩浆和构造因素综合影响下,垂向上矿化和蚀变带呈现出深部与辉钼矿伴生的面状云英岩化蚀变带,至浅部与铅锌矿伴生的脉状绢云母化、硅化蚀变带的立体组合。平面上由于斑岩侵入路径不同;越靠近深部岩浆房顶部地区斑岩易分异出高温流体,相应的这也是区内高温矿化蚀变的分布区。5.斑岩及接触围岩中没有发现UST石英说明了断裂系统是半封闭环境。斑岩上侵并未伴随来自岩浆房出溶的大量流体,所以区内流体主要是由斑岩就位后出溶流体。岩浆冷凝早期出溶流体使钼元素迁移并在压力减小的环境影响下沉淀富集成矿。岩浆冷凝晚期出溶流体萃取铅锌并在温度下降的环境影响下沉淀富集。
[Abstract]:A thousand areas are located in the southwestern part of Hainan Island, located at the intersection of the Lingshui - nine deep fault and Baisha fault depression. In recent years, a number of ore deposits (points) with good metallogenic prospects have been found in the southwest of Hainan Island. Their distribution has a certain regional law: (1) the deposit (point) Cheng Yinxiang 2. The mineral deposits are mostly molybdenum, tin, gold, lead and zinc metal deposits (points); (3) the distribution of deposits (points) is closely related to Mesozoic magma tectonic movement, mostly distributed in the edge of magma rock mass or in the vicinity of the formation zone. It also shows some distinct characteristics: ore deposits (points) are often distributed in rock mass. Based on the achievements of previous studies and combined with the results of field geological survey, the metallogenic regularity of thousands of areas is discussed by comprehensive utilization of petrology, mineral deposits, geochemistry, geophysics, mineralogy, isotopic geology and ore forming law and prediction. On the basis of regional geological background, we carefully understand the geological conditions in the area. On this basis, we carefully compare the Shimen mountain molybdenum lead zinc mine, the later Wan Ling lead zinc mine and the tree ridge silver deposit. It has been found that the three types of ore deposits have some common characteristics: mineralization is related to the late porphyry intrusion activities; the deposit is controlled by the north and south, the north west fault structure is obviously controlled, the rock base of the ore body This is a kind of granitoid; mineralization has a positive correlation with the degree of alteration of surrounding rock; the ore structure is usually disseminated, fine vein and breccia filling, and the genesis of the deposit is related to the similar mineralization time. Based on the careful observation of the deposit (point), the metallogenic geological conditions in the study area are deeply analyzed from point and surface, and the metallogenic regularity in the area is discussed. The following understanding is formed: Although the 1. stratum is an important metallogenic factor in the region, it is considered that the deposit (point) in the study area is mostly distributed in the rock mass and the distribution of the strata is extremely limited. It is considered that the magmatic rocks in the.2. area are mainly a thousand pluton intrusions of granitoid magma and late intrusive porphyry. The whole rock mass conforms to the basic geological features of the molybdenum lead and zinc ore bodies in Southern China area. The main trace elements of the rock mass show that thousands of rock masses have undergone changes in the physical environment of the diagenesis and strongly weathered after diagenesis. In this background, the intrusive late porphyry can not only divide the molybdenum containing fluid, but also drive the ore containing fluid in a certain fracture tensional space to circulate the lead and zinc metallogenic element.3., which is coupled with the porphyry intrusion time, and the fracture tensional space provides space for porphyry invasion and hydrothermal mineralization, and the multiple phases of the fracture are at the same time. It is easy to form 1.5 closed system in the fracture zone, which is beneficial to the comprehensive influence of molybdenum, lead and zinc enrichment and precipitation of.4. magma and tectonic factors. The vertical mineralization and alteration zone present a surface like mica alteration zone associated with the molybdenite, to the pulse sericite associated with the lead and zinc deposits, and the stereoscopic combination of the silicified alteration zone. Because the porphyry intrusion paths are different, the porphyry near the deep magmatic roof area is easily separated from the high temperature fluid, and this is also the distribution area of the high temperature mineralization and alteration in the region. The.5. porphyry and the contact surrounding rock do not find UST quartz indicating that the fracture system is semi enclosed environment. The porphyry intrusion does not accompany a large amount of magma dissolution. Fluid, so the fluid in the region is mainly from the porphyry, and the fluid is in place after the porphyry. The early magma condenses the fluid to migrate the molybdenum element and precipitate and enrich the mineralization under the influence of the pressure decreasing environment. The magma condenses the late dissolution fluid to extract lead and zinc and precipitates and enriches under the environment of temperature decline.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.4;P618.65

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