西藏龙玛拉铅锌矿床矽卡岩矿物特征及其地质意义

龙玛拉铅锌矿床是位于冈底斯成矿带之念青唐古拉铅锌成矿亚带东段的一个典型矽卡岩型矿床。前人对矿床成矿物质来源及演化、成岩-成矿时代、矿床形成动力学背景等方面进行过一定的研究, 但对矽卡岩矿物学及分带模式还缺乏系统的研究。为此, 本文通过详细的野外地质编录、系统的镜下鉴定和电子探针分析, 开展矽卡岩矿物组合、矿物成分及其分带特征研究。矿床矽卡岩矿物主要包括石榴子石、辉石、硅灰石、绿泥石和绿帘石等。矽卡岩矿物组合和化学成分在空间上具有明显的分带性。矽卡岩主要发育在角岩与大理岩接触带, 或沿裂隙充填在围岩中, 横向上显示了从褪色角岩→石榴子石矽卡岩→深色角岩→透辉石矽卡岩(矿体)→大理岩→角岩的分带特征。垂向上由顶板至底板表现出从角岩→石榴子石矽卡岩→透辉石矽卡岩→大理岩→石榴子石矽卡岩→透辉石矽卡岩→角岩的岩性分带特征。矿床石榴子石为钙铁-钙铝榴石类质同象系列(And7.92~88.63Gro5.92~86.46Pyr+Spe1.04~5.11), 端员组分变化范围较大, 表明矽卡岩的形成环境并不是完全封闭的体系。通过对铅锌主矿体的赋矿矽卡岩中石榴子石进行研究, 表明成矿流体是从矿区南西方向向北东方向运移就位形成主矿体, 为矿区寻找成矿岩体及深部找矿提供指导。     

华北地区铅锌矿资源特征及成矿规律

华北地区铅锌矿资源丰富、类型多样,是我国铅锌矿床的重要产区.本文在总结资源禀赋、矿床类型、时空特征、主要控矿因素、资源潜力等要素基础上,较全面分析了华北地区铅锌矿的主要特征和成矿规律.研究表明,从矿床成因角度,华北地区铅锌矿可划分为岩浆热液型、碳酸盐岩-细碎屑岩型、陆相火山岩型、矽卡岩型、斑岩型、碳酸盐型等6种类型,并...     

Diagenetic and Mineralization Age of the Hehuaping Tin-polymetallic Orefield, Hunan Province

The Hehuaping tin deposit is a large deposit found in recent years during geological surveys. The discovered tin deposit includes not only rock-alteration type deposits in fault zones, but also deposits developed in interstratified rupture zones between Devonian carbonate rocks (Qiziqiao Formation) and sandstone (Tiaomajian Formation). The finding of tin deposits of the latter type has greatly enriched tin-mineralization types in the famous Nanling polymetallic metallogenetic region and may provide us with a new potential orientation for prospecting of tin deposits in the region. It is commonly believed that the forming of the tin deposits in the Nanling region should be related to the Yanshanian instead of Indosinian granitic magmatism. Systematical zircon U-Pb SHRIMP dating in this paper shows that tin mineralizations have endured at least two stages. The early stage should be related to the intrusion of the main body of the Wangxianling granite, which was emplaced during the Indosinian period with a diagenetic and mineralized age of 224.0±1.9 Ma (MSWD=0.54), and the late stage should be related to the intrusion of Yanshanian granitic porphyry that took place after 142±3 Ma (MSWD=0.5).     

扬子板块北缘马元铅锌矿床有机地球化学特征及成矿作用

近年来,有机质与金属成矿关系研究备受关注.扬子板块北缘马元矿床铅锌矿体分布与古油藏、沥青在空间上叠置,是探索有机质与铅锌成矿关系的理想地区.矿区发育分散有机质、沥青、气态烃类等不同赋存形式的有机质,生物标志化合物特征明显,以低碳数正构烷烃为主,具浅海环境藻类来源特征,均处于过成熟演化程度.沥青206Pb/204Pb值为...     

甘肃省西和县页水河铅锌矿床地质特征及找矿方向

甘肃省西和县页水河铅锌矿地处西秦岭铅锌(金)多金属成矿带之西成铅锌矿田的西部,经过多年生产探矿,矿床规模不断扩大.铅锌矿体产于中泥盆统红岭山组生物灰岩与千枚岩接触部位,其含矿性与地层层位、特定的岩性、褶皱及断裂的关系密切.文章总结了矿床地质特征,分析了控矿因素及找矿标志,指出了下一步的找矿方向.     

巧家松梁铅锌矿床Ⅰ号矿体分布区1260中段构造岩地球化学特征

云南巧家松梁铅锌矿床系滇川黔铅锌成矿域内赋存于震旦系灯影组白云岩中的富铅锌矿床,它严格受构造控制.文章在讨论矿床地质特征的基础上,选择Ⅰ号矿体1260中段36个断裂构造岩样品进行研究.认为NW向断裂带内铅锌矿脉的形成早于NE向顺层产出的铅锌矿脉,构造岩存在Zn-Pb-Fe、caO-MgO-Na,O和Al2O3-K2O三种元素组合.Zn-Ph-Fe组合和CaO-MgO-Na2O组合呈负相关关系.前者为铅锌成矿作用的元素组合,后者代表了沉积作用和热液蚀变作用的复合产物;Al2O3-K,O元素组合反映了断裂作用产生的黏土矿物.微量元素分析结果表明,自矿体中心向外存在Zn-Cd-Ga、Pb-Ag-Ge元素分带,这对成矿预测具有重要意义.     

江西相山铀矿田沙洲矿床流体包裹体研究

对江西相山铀矿田沙洲矿床方解石、石英和萤石流体包裹体的研究发现, 流体包裹体均一温度主要在200~210℃和230~260℃两个区间内, 盐度w(NaCl)分别为11.00%~12.00%和18.00%~20.00%, 平均密度为0.94g/cm3, 成矿压力为168.4×105~433.0×105Pa, 平均值为283.8×105Pa。由压力与深度的关系估算成矿深度值为0.561~1.443km, 平均值为0.946km; 结合流体包裹体成分和稳定同位素等分析, 得出成矿流体主要来自大气水, 并且有岩浆水以及地幔热液的参与。      

新疆伊宁县塔北铅锌矿床地质特征和S、Pb、C、O同位素组成

塔北铅锌矿床是西天山吐拉苏盆地中新近勘查成功的一个重要热液型铅锌矿床。矿体赋存于晚泥盆世-早石炭世大哈拉军山组第五岩性段酸性凝灰岩中,受断裂构造控制。矿石硫化物的δ³⁴S值介于0.5‰~7.3‰,估算获得成矿流体的总硫同位素值δ³⁴S_∑S约2.7‰,具岩浆硫的特征。晚期石膏的δ³⁴S值为4.7‰~5.3‰,表明石膏可能是火山热液中的SO₂发生歧化反应或火山喷发带出的H₂S挥发分在近地表的氧化环境中反应生成的。矿石铅同位素组成十分稳定,并与大哈拉军山组火山岩的铅同位素组成相似,指示成矿物质来源于赋矿火山岩。碳、氧同位素组成指示成矿流体中碳主要来源于深部岩浆。塔北铅锌矿床可能属于矿化较深的浅成低温热液型矿床。     

湘南骑田岭芙蓉锡矿田流体包裹体特征和成分

芙蓉矿田流体包裹体研究表明,从成岩到主成矿阶段的有关矿物中,以富含CO2包裹体和出现大量高盐度包裹体为特征.从成矿作用早期到主成矿期直至成矿期后无矿石英脉,其均一温度由290～560℃逐渐降至230～450℃（主成矿期）,无矿石英脉仅为150～220℃;其盐度w（NaCl）相应由47%～67%逐渐降至10%～57%,最后为4%～6%.似伟晶岩石英、矽卡岩的透辉石中群体包裹体的气、液相成分研究表明,成矿流体的主要成分是H2O（w（H2O）=66.34%～71.54%）和CO2（w（CO2）=28.33%～33.5%）,其CO2含量比大脉型W,Sn矿床中的CO2含量高出一个数量级,同时远远高于大厂锡石-硫化物型锡矿床中的CO2含量;溶液中的阳离子主要是Na＋,其次是K,Na＋/K＋=16;阴离子中Cl-很高,其Cl-/H2O比值较大脉型W,Sn矿床高一个数量级以上,但与大厂锡石-硫化物型锡矿床中的Cl-/H2O比值较接近.似伟晶岩石英、矽卡岩的透辉石和锡石-硫化物石英中单个包裹体的激光拉曼光谱分析同样表明,其成矿流体主要是H2O,其次是CO2,液相中x（H2O）= 66.9%～89.1%, x（CO2）=8.1%～15.5%.     

A Preliminary Review on the Metallogeny of Pb-Zn Deposits in China

Lead and zinc resources are abundant in China, with the reserves of 100 million tons ranking only second in the world. There are more than 3000 lead-zinc mine areas nationwide. The classification of lead-zinc (Pb-Zn) deposits has been a highly controversial issue. From the standpoint of evaluating the potential of mineral resources, we construct a Pb-Zn deposit predictive type of classification scheme, and propose a Pb-Zn deposit comprehensive classification scheme (including 5 classes and 13 sub-types) that regards mineralization as the primary factor and the ore rock as secondary. According to the temporal and spatial distribution of Pb-Zn deposits, we conclude that a multi-period, multi-cycle orogenic environment is the most favorable for lead-zinc deposit growth, that the Proterozoic is the major eon for the growth of igneous-type deposits, the Paleozoic is an important development era for sedimentary Pb-Zn deposits, and the Mesozoic and Cenozoic are the heyday eras of magmatic type lead-zinc deposits. On this basis, we analyse the relationship between tectonic evolution and Pb-Zn metallogenic, and propose that the key factors determining geological mineralization are the metallogenic epoch of mineralization and tectonic environment, which determine the temporal and spatial distribution.