与韧性剪切带有关的不同金矿化类型地质地球化学特征对比研究

与韧性剪切带有关的金矿化类型主要有蚀变糜棱岩型、构造蚀变岩型和石英脉型。不同金矿化类型具有不同的控矿构造类型 ,蚀变糜棱岩型金矿化受韧性变形带控制 ,构造蚀变岩型金矿化受脆性碎裂岩控制 ,石英脉型金矿化则受浅部裂隙带控制 ;未矿化糜棱岩变形越强 ,金元素含量就越低 ,超糜棱岩明显低于粗糜棱岩 ,但强烈变形的糜棱岩容易叠加后期的矿化蚀变 ;在时空关系上 ,同一成矿期内石英脉型金矿化稍晚于构造蚀变岩型和蚀变糜棱岩型金矿化 ,且石英脉型往往穿切蚀变糜棱岩型和构造蚀变岩型 ;在地球化学特征方面 ,与构造蚀变岩型和蚀变糜棱岩型相比 ,石英脉型的轻重稀土元素比值较大 ,更富集轻同位素 ;在成矿物理化学条件方面 ,与构造蚀变岩型和蚀变糜棱岩型相比 ,石英脉型的成矿温度低、压力小、成矿深度浅。从构造带成生演化的时空统一的角度分析可知 ,这三类金矿化都是在造山过程中韧性剪切带持续演化变形的条件下形成的 ,这种韧性剪切带持续演化变形是形成大型金矿床的重要条件之一。     

中国东南沿海金、银矿床区域成矿规律

中国东南沿海的金、银(银铅锌)矿床平行东海岸线分带,东带以银矿化为主,西带以金矿化为主。金、银矿床(点)明显地受断裂构造和火山构造所控制,矿床类型主要有变质热液型、火山(含次火山)热液型、地热水溶滤型和岩浆—热液型。成矿物质是多来源的,主要来自前寒武纪基底变质岩系或古大陆壳。成矿水介质除变质热液型金矿床以变质水为主外,其他类型矿床大气降水起着重要作用。在此认识的基础上,探讨区域金、银矿床的成矿作用,提出成矿作用图式。     

电解退镀法退除金银镀层废件中的金和银

应用电解退镀法退除金银复镀层，金镀层和镀层废件中金和银。结果表明，浓硫酸－脂肪醇体系中，最佳退镀条件为电解电压８Ｖ，脂肪醇添加量１５ｇ／ＬＨ２ＳＯ４，搅拌后退镀液呈紊流态，Ｒｅ为２８８０。退镀后金主要存在于固相沉淀物中，其含量在９３％以上，而银存在于固相沉淀物和溶液中，它在两相中的分配比依不同镀层种类而异。     

HYDROMETEOROLOGICAL SIGNIFICANCE OF RIME ICE DEPOSITS IN THE COLORADO ROCKIES1

ABSTRACT Observations and measurements were made during storm periods at mountain top sites in the Colorado Rockies during the winter of 1981-1982. On average, liquid clouds occurred with and without snowfall for, respectively, 75 percent and 15 percent of the observations. On average, the rime ice deposition rates were measured to be seven times the precipitation rates. The rime deposits were estimated to contribute 10 percent to the water content of the snowpack. Combining this figure with the estimated rime deposits on falling snow crystals (up to 50 percent by mass), up to 60 percent of the water content of the annual snowpack in the mountains near Steamboat Springs, Colorado, could be due to rime ice deposits.     

Environmental resource management on the Munduruku savanna

For 13 years, the Munduruku were observed living in the savanna region located in South America in the Brazilian state of Pará. The area is near the point where the states of Pará, Amazonas, and Mato Grosso join their borders, and is utilized by about 200–300 Munduruku Amerindians. Their subsistence staple is manioc (a cassava), with fruits and meat included in the diet. Gold mining by Brazilians is a disruptive element in the resource management of the savanna habitat on the rim of the Amazon Basin. Direct and indirect results of mining interference are described. A study of the manner in which the Munduruku on the Cururu River (a tributary of the Tapajós) have handled the potentially disruptive rubber tapping suggests possible ways of reversing the interference. Several courses of action are discussed.     

Microbe-mediated sustainable bio-recovery of gold from low-grade precious solid waste: A microbiological overview

In an era of electronics, recovering the precious metal such as gold from ever increasing piles of electronic-wastes and metal-ion infested soil has become one of the prime concerns for researchers worldwide. Biological mining is an attractive, economical and non-hazardous to recover gold from the low-grade auriferous ore containing waste or soil. This review represents the recent major biological gold retrieval methods used to bio-mine gold. The biomining methods discussed in this review include, bioleaching, bio-oxidation, bio-precipitation, bio-flotation, bio-flocculation, bio-sorption, bio-reduction, bio-electrometallurgical technologies and bioaccumulation. The mechanism of gold biorecovery by microbes is explained in detail to explore its intracellular mechanistic, which help it withstand high concentrations of gold without causing any fatal consequences. Major challenges and future opportunities associated with each method and how they will dictate the fate of gold bio-metallurgy from metal wastes or metal infested soil bioremediation in the coming future are also discussed. With the help of concurrent advancements in high-throughput technologies, the gold bio-exploratory methods will speed up our ways to ensure maximum gold retrieval out of such low-grade ores containing sources, while keeping the gold mining clean and more sustainable.     

淮北地区矽卡岩型铁铜矿床控矿条件分析与成矿模式

淮北地区位于安徽省北部,是重要金属成矿区之一.地质构造单元归属华北陆块,其矽卡岩型矿床的控矿条件和成矿模式既与华北地区邯邢式接触交代型铁矿床相似而又有区别.邯邢式铁矿主要围岩地层为奥陶系,矿石成分简单,以磁铁矿为主.淮北地区部分矿床具有这一特征,而另一部分矿床的特征与此有较大差异:围岩地层为寒武系,矿石成分复杂,以铁铜矿为主,并含有金、钼等其它有益元素,岩体分叉侵入,多层成矿,矿体产于燕山中期石英二长闪长玢岩与寒武系中上统内接触带及正接触带,镁质矽卡岩较发育,含铜矽卡岩可见于外接触带.为了与邯邢式铁矿区别,称其为前常式铁铜矿.本区矽卡岩型矿床的赋矿层位为中上寒武统-下奥陶统.其中,寒武系铁矿比例43.39%、铜矿比例92.67%、金矿比例100%,奥陶系铁矿比例56.61%、铜矿比例7.33%.本文在介绍地质背景的基础上、较系统地分析了控矿条件和成矿模式,提出了岩浆侵入活动中心(或活动带)与寒武系接触带为重点找矿方向的观点,并明确指出远离侵入中心(带)的岩床,其成矿性差.文中还介绍了覆盖区识别岩浆侵入活动中心(或活动带)的方法.     

Lead in particulate deposits and in leaves of roadside plants, Karachi, Pakistan

Lead concentrations were determined for particulates which were deposited during one year on the leaves of roadside plants in Karachi. The particulates were collected from the leaves at a height of one metre. The lead accumulated by the leaves of different species was also measured. A statistically significant correlation was found between the number of passing petrol driven vehicles and the lead concentration in the deposits at different designated sites. However, no significant correlation was found between the concentration in the deposits and the lead accumulated by the leaves. A lead concentration of 30.00±6.6 ppm was recorded as the highest concentration in the particulate deposits, while maximum lead accumulated by the leaves was noted as 3.12±1.09 ppm.     

Self-enforcing environmental agreements and trade in fossil energy deposits

The literature on self-enforcing environmental agreements (SIEAs) focuses on de- mand-side emission-reduction policies. To our knowledge, Harstad (2012) is the only study on SIEAs, in which countries purchase fossil-energy deposits to prevent their exploitation. He finds that for any coalition size there exists a (small) subset of parameters, different for each size, such that the coalition of that size is stable. However, the comparison of Harstad's results with the prevailing demand-side SIEA analyses is hampered by major differences in the structure of the respective game models. This paper develops a game model with a deposit market and deposit purchases for preservation that is in line with some demand-side SIEA literature. It turns out that either no coalition is stable or the grand coalition is the only stable coalition. We compare the outcome of our model not only with Harstad's model but also with Eichner and Pethig's (2015) model of the formation of SIEAs in which climate policy takes the form of (demand-side) emissions taxes.     

Sources and Sinks of Phosphorus for a Perturbed Stream and the Effects of Mineral Deposits1

Effler, Steven W., Anthony R. Prestigiacomo, David A. Matthews, and Feng Peng, 2012. Sources and Sinks of Phosphorus for a Perturbed Stream and the Effects of Mineral Deposits. Journal of the American Water Resources Association (JAWRA) 48(2): 321‐335. DOI: 10.1111/j.1752‐1688.2011.00617.x Abstract: Patterns of concentrations and loading rates of multiple forms of phosphorus (P) are resolved and analyzed along Ninemile Creek, New York, a stream perturbed by a domestic waste discharge and residual effects of a closed industry. This analysis is based on biweekly monitoring of total, dissolved, and soluble reactive P (SRP) for 19 months at four sites that bracket each of these effects, and 15 years of biweekly measurements at the two sites that bound industrial deposits. The minerogenic particle populations of the stream and the surficial sediments along the reach with extensive CaCO₃ and clay mineral deposits are characterized with an individual particle analysis technique. Mass balance analyses depict: (1) increasing nonpoint inputs of particulate and dissolved organic P along the stream length; (2) input of P from a domestic waste facility, almost entirely in the form of SRP; and (3) a compensating downstream loss of SRP over the reach with the extensive industrial deposits of CaCO₃. The downstream sink process for SRP is attributed to sorption processes with minerogenic deposits. The domestic waste‐based source and the compensating industrial waste‐based sink are noteworthy fluxes relative to other prevailing loads received by downstream Onondaga Lake, for which a major rehabilitation program targeting cultural eutrophication is underway. The P source/sink conditions of this stream are considered in the context of this rehabilitation program.