粤北下庄铀矿田碳、氧同位素研究     

商朋强  胡瑞忠  毕献武  刘雷  张国全 《矿物岩石地球化学通报》2006,25(Z1):181-183

下庄矿田是华南重要的热液铀矿产区,区内控矿条件复杂.本文选取下庄矿田部分矿床内热液碳酸盐样品并测定其碳、氧同位素组成,测得与成矿有关的碳酸盐的δ13CPDB值为-3.1‰～-8.8‰.研究结果表明,成矿流体中矿化剂∑CO2主要来源于中新生代与区域深大断裂有关的幔源脱气作用,同时伴有壳源有机碳来源;成矿同时期伴随的强烈流体脱气(CO2)作用对矿质沉淀至关重要.  相似文献   

内蒙古东胜砂岩型铀矿床形成条件与成矿作用   总被引：21，自引：0，他引：21  

张复新  乔海明  贾恒 《地质学报》2006,80(5):733-739

鄂尔多斯盆地是中国煤、油、气、铀四大能源集一体的最大能源盆地之一,是统一在华北地台的太古宙、元古宙古老结晶岩系及古生代海、湖相台盆基础上,于中生代从华北地块分异出来并发育的中—新生代山前凹陷盆地。中—新生代盆地经历了台盆发育、断块活动及盆后活动阶段。本文分析了中—新生代盆地放射性铀成矿盆地地质及地球化学有利条件,铀的丰度(4.71×10-6～34.3×10-6)是上地壳平均丰度,甚至高出一个数量级。阐述了东胜铀矿容矿层的岩石学特征,成岩—后生—低温热液矿化蚀变特征。分析了与铀成矿作用密切相关、呈面型展布、分别产于矿体上、下盘的绿色化及漂白色蚀变形成与深盆气密切成因关系。矿床矿化蚀变作用具有:多期次多阶段成矿特点、矿化矿物组合复杂、矿化形式多样、成矿温度具低温热液特点(70～120℃)、绿色化及漂白色蚀变具面型分布,矿床属于沉积预富集—古层间氧化淋滤—后生二次还原与交代砂岩型铀矿床。  相似文献   

河南前河金矿岩石矿物特征   总被引：6，自引：1，他引：6  

裴玉华  严海麒  张明云 《矿产与地质》2006,20(4):513-518

前河金矿属构造蚀变岩型。容矿岩石为正长斑岩，矿体大小不等，控矿破碎带内的岩石曾经受到早期塑性变形和晚期脆性变形两个阶段。容矿岩石及矿体围岩曾受多次热液蚀变作用，可分为三个成矿期：岩浆热液期、表生期和沉积期。岩浆热液期为最主要的成矿期，由四个矿化阶段组成。一种富铁黄铜矿在金矿石中广泛存在，可作为金矿石的指示矿物。  相似文献   

Six thousand years of records of metal mining and utilization from lake sediments in central China     

Celine S.L. Lee Shihua QI Gan Zhang Xiangdong LI 《中国地球化学学报》2006,25(B08):20-20

A sediment core from the Liangzhi Lake, Hubei Province in central China, was used to assess metal usage and accumulation in the past 6000＋ years in China. The concentrations of trace metals, including Cr, Cu, Pb, Ni and Zn, and major elements, Ca, Fe and Mg, in the ^14C-dated sediment core were analyzed. Historical trends of metal inputs to the Liangzhi Lake from 5000 B.C. to the present were recorded in the sediments, representing over 6000 years of metal mining and utilization history in China. The concentrations of Cu, Ni, Pb and Zn have increased gradually since 3000 B.C., indicating the start of the Bronze Age era in ancient China, until the period 467-76 B.C. During the period of 467-76 B.C., there had been a rapid increase in the concentrations of these metals in the sediments, indicating the enormous inputs of these metals at that time. This era corresponded well with the Warring States Period （475-221 B.C.） and early Hart Dynasty （206 B.C.-220 A.D.） of China, during which copper and lead were extensively used in making bronze articles, such as vessels, tools and weapons. During 1876 A.D. to the early 1900s, there was also a significant increase in the metal concentrations, such as Cu, Ni and Pb, which could probably reflect the impact of metal emissions during the early industrial development and wars in China. The Pb isotopic analysis showed that the surface and subsurface sediments had lower ^206Pb/^207Pb, and ^208Pb/^207Pb ratios than the deeper layers, affected by mining activities both during the Bronze Age era and modem times.  相似文献   

Effects of the addition of complexants and bacteria on the soil-plant transfer at metal contaminated sites     

Manfred Sager Hyo Taek Chon Jin Hee Park 《中国地球化学学报》2006,25(B08):89-89

Within a series of pot experiments with substrates sampled at heavily to moderately polluted sites of past metal mining activities, it was tried to influence the soil plant transfer of metals via addition of complexants, soil bacteria and perlite. Lettuce （lactuca sativa） was chosen as a universal accumulator plant. A wide range of concentrations in the samples ensures a rather general approach. The goal was to develop a strategy to enable plant growth at metal contaminated substrates for phytoremediation purposes. One contaminated mine tailing from Shiheung/Korea was treated with EDTA, NTA, citric acid, malic acid, NaCl, citrate＋NaCl, as well as compost, to provoke effects from chemical treatment. This should yield low molecular metal complexes in the soil solution and provide a carbon source to natural soil life. Other samples from Shiheung, from Okdong mine tailings, Okdong farmland, as well as from three contaminated sites from a medieval mine tailing at Oberzeiring/Styria/Austrias were treated with Cd- adapted soil bacteria, perlite, and soil bacteria and perlite, to impose of changes in microbial life directly. Fresh mine tailings are low in microbial life and plant- available nitrogen, whereas in the contaminated Austrian medieval samples, conditions have had time to adapt for more than 600 years. In the test substrates, supply with nutrient nitrogen was low, supply with nutrient phosphorus was low to adequate, and supply with potassium and sulfate was adequate. Effects of various additives on the plant yield mainly depend on the initial nutrient status. After harvest, the soils were parted in root soils and bulk soils to recognize possible differences. The lettuce plants were parted in leaves and roots. The solids were characterized by convential methods and aqua regia digestion, as well as by a Tessier-type sequential leaching procedure. The plant samples were digested with HNO3/HClO4. Basically, sample solutions were simultaneously read for 23 elements in ICP-OES in appropriate dilutions. Various treatments result in concentration shifts in root soil, bulk soil, plant roots and plant leaves. Interpretation is not easy, but physiologically active elements or contaminants are usually more involved.  相似文献   

河北围场发现金多金属成矿带     

徐桂林  孟庆芳 《河北地质》2006,(2):32-32

河北围场朝阳湾金矿，1：1万地质填图发现金矿点20处、矿化点40处。金矿最高品位达每吨18克。  相似文献   

内蒙古大井锡多金属矿床锡矿物特征   总被引：3，自引：0，他引：3  

王玉往  王京彬  王莉娟 《地质与勘探》2006,42(4):51-56

大井锡多金属矿床含锡矿物为锡石和黄锡矿,产于3个成矿阶段和5种矿石类型中.从早到晚,即韧性变形阶段→锡石-毒砂-石英阶段→锡石-硫化物阶段(或黄铜矿-黄铁矿阶段),主要含锡矿物锡石的化学成分,表现出SnO2逐渐升高而FeO、TiO2、Nb2O5、Ta2O5和In2O5依次跳跃式递减的特征,同时NiO和Ga2O5趋于升高.与一般脉状锡矿床相比,早阶段锡石富Ta而晚阶段锡石富Ti、Fe,表明早期的锡石更接近花岗质岩浆源特征而晚期锡石则明显具层控性质.锡石的组分变化特征与各阶段(内)从早到晚成矿温度递减有关.另一含锡矿物黄锡矿含As、Zn较高,仅出现于锡石-硫化物阶段,并在温度为220℃～320℃、硫逸度为10-10.04×105～10-13.44×105Pa的特定区间内淀出.两个阶段锡石的稀土元素特征分别与矿区次火山岩和林西组地层一致,表明早期锡石-毒砂-石英阶段中的锡主要来自次火山岩(如英安斑岩),而晚期锡石-硫化物阶段中的锡可能主要来自林西组围岩(如粉砂岩).  相似文献   

四川盐源马丝螺地区1：5万水系沉积物测量成果及金矿找矿方向     

王仁宗 《四川地质学报》2006,26(4):218-222

阐述了盐源马丝螺地区破碎带中金矿(化)体特征,结合该地区1:5万水系沉积物测量所圈定的组合异常特征、成矿元素地球化学特征,提出了该地区的找矿标志,指出了找矿方向。  相似文献   

长城堡岩体西段放射性水文地质特征及其找矿方向     

董光国  戴永久 《铀矿地质》2006,22(2):104-109,128

文章论述了长城堡岩体西段放射性水文地质特征、水化学异常特征和铀矿化特征，探讨了三者之问的相关关系；指出该区铀矿化受水化学异常区和水文地球化学垂直分带的控制，铀主要富集在氧化-还原过渡带；根据该区铀易浸出的特点，认为适合于用溶浸和地浸法开采。  相似文献   

赣南崇义地区淘锡坑钨矿的地质特征与成矿时代   总被引：55，自引：0，他引：55  

陈郑辉  王登红  屈文俊  陈毓川  王平安  许建祥  张家菁  许敏林 《地质通报》2006,25(4):496-501

江西省崇义县淘锡坑钨矿区位于南岭东西向构造带东段与武夷山北东-北北东向构造带南段的复合部位,是九龙脑-淘锡坑矿田的一个重要矿区,属于以石英脉型黑钨矿为主的钨多金属矿床.矿脉穿切于震旦系中,成矿主要受北西向断裂控制,成因与燕山期岩浆作用有关.选取含矿石英脉中与黑钨矿共生的辉钼矿进行Re-Os等时线年龄的测定,得到辉钼矿的等时线年龄为154 4Ma±3.8Ma,黑钨矿的模式年龄为164.0Ma±2.7Ma,表明该矿床形成于燕山早期.  相似文献