前寒武纪沉积岩地球化学特征及其对地壳演化的指示意义

本文介绍了运用前寒武纪沉积岩地球化学特征推断地球早期地壳的组成、增生历史及太古—元古宙界面构造性质突变问题,这已成为国际前寒武纪地质研究的前沿课题,并已相继在世界典型的前寒武纪低级区及部分高级区开展了这一方面的研究工作,取得了一系列重要进展。     

Geochemical processes during five years of aquifer storage recovery

A key factor in the long-term viability of aquifer storage recovery (ASR) is the extent of mineral solution interaction between two dissimilar water types and consequent impact on water quality and aquifer stability. We collected geochemical and isotopic data from three observation wells located 25, 65, and 325 m from an injection well at an experimental ASR site located in a karstic, confined carbonate aquifer in South Australia. The experiment involved five major injection cycles of a total of 2.5 x 10(5) m3 of storm water (total dissolved solids [TDS] approximately 150 mg/L) into the brackish (TDS approximately 2400 mg/L) aquifer. Approximately 60% of the mixture was pumped out during the fifth year of the experiment. The major effect on water quality within a 25 m radius of the injection well following injection of storm water was carbonate dissolution (35 +/- 6 g of CaCO3 dissolved/m3 of aquifer) and sulfide mineral oxidation (50 +/- 10 g as FeS2/m3 after one injection). < 0.005% of the total aquifer carbonate matrix was dissolved during each injection event, and approximately 0.2% of the total reduced sulfur. Increasing amounts of ambient ground water was entrained into the injected mixture during each of the storage periods. High 14C(DIC) activities and slightly more negative delta13C(DIC) values measured immediately after injection events show that substantial CO2(aq) is produced by oxidation of organic matter associated with injectant. There were no detectable geochemical reactions while pumping during the recovery phase in the fifth year of the experiment.     

阿拉斯加南部海岭俯冲作用与金矿成矿作用之间的联系

阿拉斯加南部海岭俯冲作用与金矿成矿作用之间的联系Ｐ．ｊ．Ｈａｅｕｓｓｌｅｒ等阿拉斯加南部基来和楚加奇山脉以过积岩为主的成脉金矿床具有奇特的构造背景，位于巨大的堆积杂岩体内．弧前区热液流温度较低，很难想象在此地质背景中会出现热液循环和金矿成矿作用．中生...     

澳大利亚“UNCOVER”计划研究进展

“UNCOVER”计划是澳大利亚科学院为了应对找矿发现成功率下降, 维持国家矿业繁荣而开展的一项综合性地学研究项目。该计划由1个勘查地学研究网以及盖层属性研究、岩石圈结构研究、成矿过程演化模拟及矿物质运移印迹等4项行动构成, 目的是通过号召澳大利亚科学家在一个创新的、结构化的和全国协调的战略联盟中开展合作, 提升澳大利亚覆盖区的找矿成功率, 为澳大利亚矿产勘查创造竞争优势。该计划吸引并调动了勘查行业、大学研究团体、政府地学机构和合作研究中心等多方力量的参与, 是“产学研”的典型代表, 其做法值得思考与借鉴。     

铜资源现状与发展态势分析

进入21世纪以来,全球矿业走出低谷,步入了新一轮矿业繁荣周期.铜作为一种重要矿种,在过去的十多年里,经历了空前的繁荣,铜矿勘查开发投入屡创新高,国际铜价在中国、印度等新兴经济体强劲需求的带动下,走向高位,甚至出现了过度金融化倾向,价格泡沫化严重.中国国内铜储量严重不足,对外依存度高达70％,外加国际铜价虚高,对中国贯彻落实“立足国内,充分利用国内国外两种资源市场”的战略方针提出了严峻挑战.文章较为系统地总结了全球铜资源的总体发展态势以及中国铜资源的基本现状和特点,并对未来十年中国铜资源的供需形势进行了预测,提出应立足国内,以地质找矿新机制为核心,加大后续勘探开发投入力度,将近十年来地质大调查查明的铜资源储量转换为铜储量,提升资源保证程度.同时,针对国际铜价出现的重大转变,应充分利用市场机制实现国家和铜产业利益的最大化.     

The dependence of organohalogen compound concentrations on herring age and size in the Bothnian Sea, northern Baltic

The concentrations and composition profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polybrominated diphenyl ethers and polychlorinated naphthalenes were determined in herring individuals collected from the commercial catches of the Bothnian Sea, northern Baltic. The median age of herring was 5.0 years and in the muscle the median toxic equivalent concentration of PCDD/Fs was 5.6 WHO(PCDD/F)-TEQ pg/g fresh weight (fw) and that of PCBs 2.7 WHO(PCB)-TEQ pg/g fw. The median sum concentration of PBDEs was 1.4 ng/g fw and that of PCNs 0.1 ng/g fw. Differences in age-dependent accumulation between the organohalogen groups and individual congeners were major. In the Bothnian Sea the content of organohalogen compounds in herring is obviously elevated due to the availability and large proportion of Mysis crustaceans in their diet. More intensive fishing could reduce the concentrations of organohalogens, including the abundant, accumulative and toxic 2,3,4,7,8-PeCDF congener in the Baltic herring catch.     

Miniaturization of the flowing fluid electric conductivity logging technique

An understanding of the hydraulic properties of the aquifer and the depth distribution of salts is critical for evaluating the potential of ground water for conjunctive water use and for maintaining suitable ground water quality in agricultural regions where ground water is used extensively for irrigation and drinking water. The electrical conductivity profiles recorded in a well using the flowing fluid electric conductivity (FEC) logging method can be analyzed to estimate interval-specific hydraulic conductivity and estimates of the salinity concentration with depth. However, operating irrigation wells commonly allow limited access, and the traditional equipment used for FEC logging cannot fit through the small access pipe intersecting the well. A modified, miniaturized FEC logging technique was developed for use in wells with limited access. In addition, a new method for injecting water over the entire screened interval of the well reduces the time required to perform FEC logging.     

2010年全球矿业形势分析及未来展望

矿业作为世界经济发展的基础,其发展动向既可反映经济发展走势,也受全球经济基本面的控制.在遭受全球金融危机后,各国经济从同步衰退走向交替性增长,复苏步伐疲软,周期被拉长.近来,美国为缓解国内失业率居高不下和刺激经济增长,采用量化宽松政策,致使美元大幅贬值;欧元区主权债务问题此起彼伏;国际流动性资本蜂拥至中国、印度等新兴发展中国家,给这些新兴国家带来严重的通胀压力.受此影响,黄金价格一路飙升,重要金属矿产品价格更是震荡走高.