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1.
本文以丰富的实际资料,论证了地下水的卤素元素(F、Cl、Br、I)的形成、含量及其分布规律与含水介质成分、上覆岩土性质、地下水退流条件、氧化还原环境、地下水矿化度之间的关系。根据江汉平原东部区和鄱阳湖区地下水中Br、I元素的调查研究结果及它们形成的控制因素与分布规律,结合长江三角洲南部区水文地球化学环境条件分析对比,指出该区是一个形成Br、I矿泉水的有利地区。  相似文献   
2.
Two cases of simultaneous nighttime measurements of NO2 and OClO in the winter polar stratosphere are analyzed in order to test our present knowledge of halogen chemistry in the presence of high amount of NO2 at low temperature. Comparisons with Lagrangian model calculations using several hypotheses are performed. First simulations, using the admitted constant rates of chemical reaction, strongly underestimate the measured OClO while the NO2 profiles are correctly reproduced. If uncertainties in actinic fluxes calculations are taken into account, simulation results do not show a significant reduction of the underestimation. A better agreement can be achieved if the formation of unstable isomers of ClONO2 and of BrONO2 occurs in the cold conditions of the polar stratosphere. An approximate value of the branching ratios of the channels leading to ClONO2 and ClOONO, and to BrONO2 and BrOONO, necessary to reproduce both OClO and NO2 is given and discussed.  相似文献   
3.
Abstract. Halogen-rich phlogopite occurs in the groundmass of andesite and dacite lavas from Late Tertiary to Quaternary volcanoes associated with native sulfur and limonite deposits (Shiretoko-Iwozan, Hachimantai, Adatara, Omeshidake, Masaki) and hydrothermal ore deposits (Harukayama, Muineyama, Hishikari) in Japan. The F contents of the halogen-rich phlogopite range from 3.6 to 5.7 wt%, corresponding to atomic F/(F+C1+OH) ratios ranging from 0.45 to 0.69. On the other hand, the Cl contents of the halogen-rich phlogopite are around 0.2 wt%. The atomic Mg/(Mg+Fe) ratios range from 0.69 to 0.83.
The fluorine intercept value [IV(F)] defined by Munoz (1984) of the phlogopites ranges from 0.79 to 3.17, and the chlorine intercept value [IV(Cl)] ranges from -7.11 to -7.77. The observed IV(F) of the phlogopites broadly overlap the range of the IV(F) for biotites from porphyry copper deposits. On the other hand, the observed IV(Cl) are significantly lower than the IV(Cl) for biotites from porphyry copper deposits. Whereas the F contents of the phlogopite appear more prominent compared to the Cl contents, the calculation of halogen intercept values revealed that the phlogopites are enriched in Cl with respect to the element distribution effect of Mg-Fe substitution. Since the degree of Cl enrichment of the phlogopite is more significant compared to that of biotite in porphyry copper deposits, the phlogopites are considered to have formed under the condition of significantly high activity of halogens. Hydrothermal ore deposits may be formed in magmatic hydrothermal system associated with volcanoes where halogen-rich phlogopite is formed by hypersaline fluid.  相似文献   
4.
5.
论述了晚第三纪塔里木盆地至藏、滇一带古构造和古地理气候背景及地层沉积特征。重点讨论了古气候对煤和盐类矿产沉积作用的影响,提出了今后找矿工作的动步建议。  相似文献   
6.
Severe chemical ozone loss has been detected in the Arctic in the winter and spring of 1995–96 by a variety of methods. Extreme reductions in column ozone due to halogen catalysed chemistry were derived from measurements of the Halogen Occultation Experiment (HALOE) on board the Upper Atmosphere Research Satellite in the Arctic vortex. Here, we discuss further aspects of the HALOE observations in the Arctic over this period. Potential problems, both in the data themselves and in the methodology of the data analysis are considered and the reason for the differences between the Arctic ozone losses deduced from HALOE data version 17 and 18 is analysed. Moreover, it is shown that HALOE measurements in the Arctic in winter and spring 1995–96 compare well with observations by other ground-based and satellite instruments.  相似文献   
7.
The Huayuan Pb-Zn ore district in China, located in western Hunan Province, is a giant carbonate-hosted Pb-Zn ore district. The source of ore-forming brines in this ore district remains poorly constrained. Whether the highly saline brines are derived from evaporated seawater or dissolved evaporates continues to be intensely debated. Carbonate minerals associated with Pb-Zn mineralization have δ13CV-PDB and δ18OV-SMOW values ranging from ?5.55‰ to +1.35‰ (mean value of ?0.69‰; n = 14) and +16.28‰ to +25.05‰ (mean value of +20.22‰; n = 14), respectively. This indicates that carbonate minerals are dominantly formed from dissolved ore-hosted carbonate rocks. The δ34S values of sulfides range from +20.2‰ to +36.8‰, with an average value of +30.0‰ (n = 27). These results suggest that sulfur is predominantly derived from the thermochemical sulfate reduction of marine sulfate. The crush-leach analyzed solute data of fluid inclusions in sphalerite show the ore-forming fluids have Cl/Br molar ratios range from 118 to 384, and Na/Br molar ratios from 39 to 160 (n = 8). These Cl/Br ratios of hydrothermal fluid are much lower than those of seawater (657 to 564), but are consistent with bittern brines through early halite precipitation. We propose that ore-forming fluids are mainly derived from evaporitic basin brines, which leached base metals from the basement and/or country rocks. The brine then migrated to the basin margins through clastic rocks of basement and then precipitated sul?des by thermochemical sulfate reduction.  相似文献   
8.
The halogen ions Br- and Cl- together with NO3 -, SO4 =, MSA- (methane sulfonate), Na+ and NH4 + were analysed by ion chromatography in extracts of more than 800 aerosol cellulose filter samples taken at Ny Ålesund, Svalbard (79°N, 12°E) in spring 1996 (March 27 - May 16) within the European Union project ARCTOC (Arctic Tropospheric Ozone Chemistry). Anticorrelated variations between f-Br (filterable bromine, i.e. water soluble bromine species that can be collected by aerosol filters) and ozone within the arctic troposphere were evaluated at a resolution of 1 or 2 hours for periods with depleted ozone and 4 hours at normal ozone. A mean f-Br concentration of 11 ng m-3 (0.14 nmol m-3) was observed for the whole campaign, while maximum concentrations of 80 ng m-3 (1 nmol m-3) were detected during two total O3-depletion events (O3 drop to mixing ratios below the detection limit of < 2 ppb). Anticorrelation between f-Br and O3 was also seen during minor O3-depletion episodes (sudden drop in O3 by at least 10 ppb, but O3 still exceeding the detection limit) and even for ozone variations near its background level (40-50 ppb). A time lag of about 10 hours between the change of ozone and of f-Br concentrations could only be found during a total ozone depletion event, when f-Br reached its maximum values several hours after ozone was totally destroyed. Bromine oxide (BrO) concentrations, measured by DOAS (Differential Optical Absorption Spectroscopy), and f-Br showed a coincident variability during almost the entire campaign (except in the case of total O3-loss). Frequently enhanced anthropogenic nitrate and sulphate concentrations were observed during O3-depletion periods. At O3 concentrations < 10 ppb sulphate and nitrate exceed their typical mean level by 54% and 77%, respectively. This may indicate a possible connection between acidity and halogen release.  相似文献   
9.
东准噶尔北缘和东天山雅满苏带是中国新疆北部地区两个重要的晚古生代铁氧化物-铜-金矿化潜力区,以老山口、乔夏哈拉和黑尖山矿床作为典型矿床代表。研究表明两区域的铁氧化物-铜-金矿床均产出于盆地闭合的弧盆转化体系下,且具有明显的铁、铜-金两阶段矿化。卤族元素和稀有气体同位素作为可靠的流体示踪剂,被应用于探究这一特定构造环境下的铁氧化物-铜-金矿床的流体演化和矿床成因。结果显示老山口、乔夏哈拉和黑尖山矿床的成矿流体具有明显的混合流体端员特征:(1)岩浆流体端员,主要参与黑尖山矿床磁铁矿阶段,I/Cl、Br/Cl和40Ar/36Ar比值分别为(16.3~18.0)×10-6、(1.03~1.06)×10-3和352~437;(2)海水表源蒸发成因盐卤水端员,主要参与老山口矿床铜-金矿化阶段,I/Cl、Br/Cl和40Ar/36Ar比值分别为(77.1~87.7)×10-6、(1.53~1.80)×10-3和672~883;(3)蒸发岩溶解或者深度水-岩反应成因的盐卤水/沉积岩地层水端员,主要参与到老山口、乔夏哈拉矿床的磁铁矿阶段以及黑尖山、乔夏哈拉矿床的铜-金矿化阶段,综合I/Cl、Br/Cl和40Ar/36Ar比值分别为(477~26 301)×10-6、(0.39~1.28)×10-3和288~510。明显的多阶段矿化和铜-金矿化阶段以非岩浆富Ca高盐度卤水为主的特征与世界范围内的IOCG型矿床极为相似,表明新疆北部的铁氧化物-铜-金矿床应为IOCG型矿床。  相似文献   
10.
对流层活性卤素化学:充满机遇和挑战的研究领域   总被引:2,自引:0,他引:2  
活性卤素物种(RHS)参与大气对流层中许多化学过程,影响许多重要物种的源和汇,在大气对流层化学中起着十分重要的作用,因此对流层活性卤素化学成为近年来国际大气化学研究的重要前沿研究领域。RHS在对流层的外场观测方法主要包括化学放大、大气压化学电离质谱(APCIMS)、长程差分吸收光谱(DOAS)、雾室和湿法化学分析法、光解法、碳同位素的比率法等。各种观测方法表明大气边界层中存在着不同种类的RHS,特别在海洋边界层、极地边界层和盐湖地区。RHS的浓度有较大的变化范围(10-12~10-10)。RHS可引起一些VOCs的氧化,影响HOx和NOx的反应,减少对流层O3,并对硫的氧化和汞化学有较大的影响。对流层RHS的源主要为有机卤素化合物的排放和海盐气溶胶的释放。在讨论RHS在对流层的循环转化的基础上,归纳总结出一个示意图;提出了现有的主要科学问题,进而展望了今后的研究前景。  相似文献   
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