【作者】 黄永卫；

【导师】 刘家军；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2010， 博士

【摘要】 浅成低温热液型矿床是金矿床中一个十分重要的金矿类型,倍受矿床学家的高度重视。浅成低温热液金矿床是黑龙江省重要的金成矿类型,近年来已发现数十个浅成低温热液型金矿床。黑龙江省东南部的完达山—太平岭成矿带,浅成低温热液型矿床数量众多,其中四平山金矿床和四山林场金银矿床是该类型矿床的典型代表。该成矿带内存在极为有利的区域成矿条件,具有巨大的成矿和找矿潜力。广泛分布的不同期次的中—酸性侵入岩,可为成矿提供成矿流体、成矿物质及热动力。大型推覆或走滑剪切与次级断裂构造,是成矿流体搬运的重要通道和成矿物质沉淀的重要场所。然而,研究区地表覆盖相当严重,工作程度还很低。因此作者在对该成矿带内典型矿床的成矿特征和形成机制进行研究的进程上,进一步分析了该成矿带的成矿规律。通过研究取得以下主要成果:1.四山林场金-银矿床以含金石英脉型矿石为主。矿石中硫化物种类多,金品位较高,Au与As、Pb、Ag、Cu等密切相关;轻稀土元素比较富集,具有中等负Eu异常,无Ce异常;单一深源硫同位素,铅同位素具有造山带铅为主的壳幔混合源;成矿流体温度为215℃-350℃,盐度较低,具有岩浆热液和大气降水混合的特点等;成矿时代为111.1~111.4Ma。该矿床是在构造带中岩浆热液与大气降水混合导致成矿作用发生和成矿物质沉淀而形成的。2.四平山金矿床的矿石类型为含金硅质岩。矿石中硫化物含量低、种类少,金品位较低,Au与Ag、Cu、Pb、As、Hg等元素密切相关;上部硅质岩具有Eu和Ce负异常,下部硅质岩中具有正Eu异常,但热泉胶结的砾岩和流纹斑岩具有Eu负异常;硫同位素组成具有深源硫和陆地硫酸盐混合特征,铅同位素具有造山带铅为主的壳幔混合源特点;成矿流体温度180℃-244℃,具有岩浆热液和大气降水混合特点;成矿时代为87~120Ma。该矿床是在构造带中成矿流体喷出地表附近导致成矿作用发生和成矿物质沉淀而形成的。3.四山林场金银矿床和四平山金矿床尽管均是浅成低温热液型矿床,但两者的产出部位和形成机制不完全相同。前者是成矿流体在地表1km以下以充填-交代形式,使成矿物质发生富集而形成的矿床;后者则是成矿流体以热泉形式喷溢出地表形成的矿床。二者是浅成低温热液成矿系统在垂直地表方向上的不同部位成矿的表现。4.完达山—太平岭成矿带中的浅成低温热液型金矿床,主要形成于五个集中区:(1)四平山-358高地;(2)跃进山—先锋北山;(3)向阳—四山林场;(4)洋灰洞—金厂;(5)神洞—东风沟。在前两个集中区的中心为金矿床,向周围及深部为铜多金属矿床。在后三个集中区的中心则以金银矿床为主,周围为铜铅锌多金属硫化矿床。作者在总结找矿标志与成矿规律的基础上,进一步指出了五个浅成低温热液型金矿床的成矿远景区。更多还原

【Abstract】 Epithermal gold deposit is a very important type of gold deposit to which deposit scientists pay a lot of attention. Epithermal gold deposit is an important type of gold deposit in Heilongjiang province, and dozens of epithermal gold deposits have been found in recent years. The Wandashan--Taipingling metallogenic belt, southeastern of Heilongjiang province, has a large number of epithermal gold deposits, such as the Sipingshan gold deposit and the Sishanlinchang gold-silver deposit. This metallogenic belt has a favorable condition for regional metallogeny, and a huge potential for both ore forming and ore prospecting. The widespread neutral-acid intrusive rocks of different stages can provide ore-forming fluid, ore-forming material and thermal power for the ore forming. The large-scale nappe structure and strike-slip shear and its secondary faults are the important channel for the ore-forming transport and the location where the metallogenic material precipitate. However, the surface mulching of the study area is rather severe and therefore the work degree is low. So the metallogenic regularity of this metallogenic belt is further analyzed based on the study of metallogenic characteristics and formation mechanism of the typical deposit in this metallogenic belt. The main results are as follows:1. The Sishanlinchang gold-silver deposit is mainly composed of auriferous quartz vein type ores. It has many kinds of sulfides and high gold grade. The Au has a close correlation with As, Pb, Ag and Cu; the REEs of the deposit relatively enriched in LREEs, which have a moderate or lower negative Eu anomaly; the sulfur isotopes are single and deep seated, and the lead isotopes indicate that the plumbum is from the earth’s mantle and crust, mainly from the crust; the ore-forming fluid has a temperature of 215℃-350℃and a low salinity with a mixture of characteristics of magmatic hydrothermal and meteoric water; and the ore-forming age is 111.1-111.4 Ma. The deposit is formed through the mineralization and the precipitation of the metallogenic materials caused by the mixture of the magmatic hydrothermal fluid and meteoric water.2. The gold-bearing quartzite is the main type ore of the Sipingshan gold deposit. This deposit has a low gold grade and a low content of a few types of sulfides; the Au have a close correlation with Ag, Cu, Pb, As and Hg; the upper quartzite has a middle negative anomaly of Eu, and the lower quartzite has a positive anomaly of Eu, but the hot spring cemented conglomerate and rhyolite porphyry both have a negative anomaly of Eu; the sulfur isotopes have a feature of the mixture of the deep-source sulfur and terrestrial sulfate ; and the lead isotopes indicate that the plumbum is from the earth’s mantle and crust, mainly from the crust; the ore-forming fluid has a temperature of 180℃-244℃, and it contains both magmatic hydrothermal and meteoric water; and the ore-forming age is 80~120Ma. The deposit is formed by the ore-forming fluid erupting from the structural belt onto the surface of the earth, causing the occurrence of the mineralization and the precipitation of the metallogenic materials.3. Although the Sishanlinchang gold--silver deposit and Sipingshan gold deposit are both epithermal deposits, they have different output area and formation mechanism. The former is the kind of deposit that the ore-forming fluid enriches the metallogenic materials by filling and metasomatism from 1 km underground; and the latter is the kind of deposit which is formed by the ore-forming fluid erupting out of the surface as a hot spring. These two deposits are the reflection of the epithermal system mineralizing at different locations in the vertical direction.4. The epithermal deposits in Wandashan-Taipingling metallogenic belt mainly formed in five concentration areas: (1)Sipingshan-358 highland; (2) Yuejinshan-Xianfengbeishan; (3)Xiangyang-Sishanlinchang; (4) Yanghuidong-Jinchang; (5)Shendong-Dongfenggou. The centers of the first two concentration areas are mainly for gold deposits, and the surrounding and deep areas are mainly for copper-polymetallic deposits. The centers of the last three concentration areas are mainly for gold-silver deposits, and the surrounding and deep areas are mainly for copper-lead-zinc sulfide deposits. Based on the summary of the prospecting criteria and metallogenic regularity, five ore prospecting areas of epithermal gold deposit are pointed out.更多还原