陕西二台子铜金床钠长石碳酸（角砾）岩类特征及形成构造背景分析

从岩石学、矿物学、岩石化学、地球化学、稀土元素等方面研究了二台子铜金矿内长石炭酸（角砾）岩类地质地球化学特征。晚泥盆世－石炭纪,在区域幔羽构造作用下,深部热流体沿先存在构造通道上升进入镇安二台子三级热水沉积盆地之中,形成了石英重晶石炭酸角砾岩、碳酸角砾岩、复成分角砾岩、钠长岩、钠长石碳酸岩,受同性断裂及层位控制明显,并构成了金的矿源层及普遍金矿化。燕山期,具有幔源特征的深部含矿热流体在北东、北西向     

川北甘南地区三叠纪岩相古地理与成矿

川北甘南地区三叠纪时期沉积的岩相古地理明显地划分为早一中三叠世早期（安尼期），扬子大陆西缘台地相碳酸盐岩沉积；和中三叠世晚期（拉丁期）到晚三叠世中期（诺利期），特提斯边缘裂陷海槽浊流相碎屑岩沉积两个迥然不同发展阶段。金和伴生多金属组分来自边缘古陆，而边缘台地相白云岩化阶段和海湾相粉砂－粘土矿物沉积阶段是促成金矿初始富集的最佳环境。     

Study of a comprehensive assessment method of the environmental quality of soil in industrial and mining gathering areas

Industrial and mining activities have been recognized as major sources of heavy metal contamination in soil. Here, we developed a comprehensive assessment method for the soil environment in industrial and mining gathering areas based on the pressure–state–response model. Using this method, we assessed the environmental quality of soil in a typical industrial and mining gathering area in Tianjin City, China. The results are as follows: (1) The comprehensive environmental quality index of the soil in the study area was 0.532, which corresponds to an alert state and shows that the soil environment is generally poor. (2) The pressure, state, and response indexes were 0.609, 0.634, and 0.163, respectively, which suggests that the pressure in the soil environment of the study area is barely acceptable, and the state is merely passable. Furthermore, the response measures are not ideal. (3) The low response index scores indicate poor production processes, low pollutant treatment level, and unsatisfactory level of management by the enterprises in the study area. (4) The distribution of soil risks was found to be inseparably related to that of contamination sources and land use types. Furthermore, the distribution was uneven to a certain degree. Finally, we propose recommendations for the optimization, adjustment, and management of typical industrial and mining gathering areas with petrochemical, metallurgy, and other heavily polluting enterprises.     

Vertical geochemical variations and arsenic mobilization in the shallow alluvial aquifers of the Chapai-Nawabganj District, northwestern Bangladesh: implication of siderite precipitation

Core sediments from three disturbed boreholes (JOR, GHAT, and RAJ) and two undisturbed boreholes (DW1 and DW2) were collected in the study area of the Chapai-Nawabganj district of northwestern Bangladesh for geochemical analyses. In the study area, groundwater samples from fourteen As-contained private wells and five nested piezometers at both the DW1 and DW2 boreholes were also collected and analyzed. The groundwater arsenic concentrations in the uppermost aquifer (10–40 m of depth) range from 3 to 315 μg/L (mean 47.73 ± 73.41 μg/L), while the arsenic content in sediments range from 2 to 14 mg/kg (mean 4.36 ± 3.34 mg/kg). An environmental scanning electron microscope (ESEM) with an energy dispersive X-ray spectrometer was used to investigate the presence of major and trace elements in the sediments. Groundwaters in the study area are generally the Ca–HCO₃ type with high concentrations of As, but low levels of Fe, Mn, NO₃ ^? and SO ₄ ^?2 . The concentrations of As, Fe, Mn decrease with depth in the groundwater, showing vertical geochemical variations in the study area. Statistical analysis clearly shows that As is closely associated with Fe and Mn in the sediments of the JOR core (r = 0.87, p < 0.05 for Fe and r = 0.78, p < 0.05 for Mn) and GHAT core (r = 0.95, p < 0.05 for Fe and r = 0.93, p < 0.05 for Mn), while As is not correlated with Fe and Mn in groundwater. The comparatively low Fe and Mn concentrations in some groundwater and the ESEM image revealed that siderite precipitated as a secondary mineral on the surface of the sediment particles. The correlations along with results of sequential extraction experiments indicated that reductive dissolution of FeOOH and MnOOH represents a mechanism for releasing arsenic into the groundwater.     

Effects of differing coverage of moss‐dominated soil crusts on hydrological processes and implications for disturbance in the Mu Us Sandland,China

To study the effects of biological soil crusts (BSCs) on hydrological processes and their implications for disturbance in the Mu Us Sandland, the water infiltration, evaporation and soil moisture of high coverage (100% BSCs), middle coverage (40% BSCs) and low coverage (0% BSCs, bare sand) of moss‐dominated crusts were conducted in this study, respectively. The conclusions are as follows: (1) the main effects of moss‐dominated crusts in the Mu Us Sandland on the infiltration of rainwater were to reduce the infiltration depths and to retain the limited rainwater in shallow soil; (2) moss‐dominated crusts have no significant effects on daily evaporation when the volumetric water content at 4 cm depth in 100% BSCs (VWC4) was over 24.7%, on enhanced daily evaporation when the VWC4 ranged from 6.5% to 24.7% and on reduced daily evaporation when the VWC4 was less than 6.5%; and (3) decreasing the coverage of moss‐dominated crusts (from 100% to 40%) did not significantly change its effects on infiltration, evaporation and soil moisture. Our results demonstrated that for the growth and regeneration of shrubs, which were dominated by Artemisia ordosica in the Mu Us Sandland, high coverage of moss‐dominated crusts has negative effects on hydrological processes, and these negative effects could not be significantly reduced by decreasing the coverage of moss‐dominated crusts from 100% to 40%. Therefore, for the sustained and healthy development of shrub communities in the Mu Us Sandland, it is necessary to take appropriate measures for the well‐developed BSCs in the sites with high vegetation coverage in the rainy season. Copyright © 2015 John Wiley & Sons, Ltd.     

台湾海峡西部海域大气中金属的特征──Ⅱ.大气颗粒金属的来源和入海通量

通过因子分析和相关回归分析,台湾海峡海域大气中颗粒物中金属的来源特征为:Fe主要来自地壳风化尘土,少量来自污染物.Pb和Cd主要来自污染源,少量Pb来自尘土和海水.Na主要来自海水,但也有少量来自尘土和次生气溶胶.Cu主要来自尘土,部分来自污染物,少量来自海水.比较台湾海峡西部海域来自大气和来自河流的金属通量,大气中的Cu低于河流,Pb高于河流,Cd略高于河流.     

东昆仑断裂东段下热尔断裂活动特征初步研究

下热尔断裂位于巴颜喀拉块体东北边界变形带即东昆仑断裂带东段与迭部-白龙江断裂2条剪切断裂之间挤压变形带内,在空间上属于“玛曲空段”范围.经野外考察及遥感资料验证,确定下热尔断裂走向为310°,长度约为20km,运动学特征表现为左旋走滑为主兼少量倾滑分量,沿断裂发育大量断错地貌,水平位移主要分布在3.5～5m,而未发现垂向断错地貌;垂直断裂走向开挖2处探槽,揭示断层切穿晚第四纪地层,被地表沼泽相泥炭层覆盖,结合相关地层年龄资料,初步得出平均水平滑动速率约为6.3mm/a.该断裂在几何学与运动学方面与东昆仑断裂带具有较好的一致性,推测两者之间存在一定相关性,属于东昆仑断裂带走滑断裂体系内的一条次级断裂或过渡性断裂.     

新疆准噶尔盆地西北部二叠纪玄武岩浆作用流体介质条件:流体化学组成及碳同位素制约

准噶尔盆地西北部深层分布着大量的二叠纪玄武岩,其发育的流体介质条件缺乏系统研究。本文采用二叠纪玄武岩岩心样品,对基质中的流体化学组成和碳同位素组成进行分步加热质谱法分析,结果表明二叠纪玄武岩的流体组成中H_2O的含量极高(平均13789mm3.STP/g),次要组分为CO_2、O_2、H_2S和N2等,CO_2和CH_4的δ~(13)C值(分别为-28.9‰~-15.8‰和-36.8‰~-21.9‰)位于地壳与甲烷氧化来源组分的范围内;CH_4、C_2H_6、C_3H_8和C_4H_(10)等甲烷同系物的碳同位素组成随碳数增高总体具有正序分布特征,400~800℃温度段释出CH_4的δ~(13)C值(-25‰左右)明显重于200~400℃的(-35‰左右),部分样品400~800℃的CH_4-C_3H_8存在碳同位素反序分布的特征,显示幔源流体挥发份特征,其中混入大量的沉积有机质热裂解成因烃类气体,应为俯冲蚀变大洋板片的沉积物脱出流体挥发份。大量的H_2O指示岛弧俯冲的再循环流体的加入,甲烷氧化来源特征的CO_2和CH_4碳同位素组成揭示经历了长期的风化过程,表明相关岩浆作用后遭受长期的抬升。     

华南二叠-三叠系的成因地层序列及古特提斯海重建

总结各类沉积盆地的沉积和地层格架，厘定出６类等时性地层界面和５个级别的成因地层单位，在分析地层界面性质和各类成因地层单位沉积构成的基础上，将华南二叠－三叠系划分为７个沉积幕、３个构造沉积幕和２个沉积盆地域、恢复了华南板块二叠－三叠纪的演化过程，论述了板块构造运动，海平面升降和源区侵蚀作用对各级成因地层单位的控制意义，证明了华南的古特提斯海经历了陆表海和伸展裂谷海两个演化阶段。     

峰丛洼地形成动力过程与水资源开发利用

对喀斯特的重要地貌景观—— 峰丛洼地(锥状喀斯特) ,从水文地貌学观点分析论述了其气候形态学特征、地貌结构、地貌发育演化动力过程以及与内源水作用过程相关的多元水赋存特点及其水资源开发利用形式。