凤凰山铜矿床两类成矿岩体的厘定及其成因分析

本文从地质、地球化学以及矿化蚀变特征等方面对凤凰山矿田内两类不同成矿岩体的特征进行了对比,指出凤凰山复式岩体由早期的花岗闪长岩和晚期的石英二长闪长斑岩所组成,与花岗闪长岩有关的成矿作用主要为矽卡岩型成矿作用,与石英二长闪长斑岩有关的成矿作用主要为斑岩型成矿作用.并对新发现的斑岩型矿化的大地构造背景、围岩、蚀变特征、控矿构造以及矿石类型进行了阐述.最后,在综合分析成矿物质来源、物理化学条件、成矿流体和成矿作用的基础上,对凤凰山铜矿床的成因进行了探讨,认为矿床的形成主要与中酸性岩浆活动有关,经历了多种成矿作用,形成了多种矿化型式,矿床成因属以岩浆热液为主的复合型热液矿床.     

梅雨期一次黄淮气旋发展的干侵入特征分析

利用水汽图像、等熵气流、θse等物理量,对2003年梅雨期的一次黄淮气旋发展过程进行了分析,试图揭示干侵入在黄淮气旋发展中的作用。分析结果表明：与干侵入相联系的水汽图像暗区的移动、发展变化与黄淮气旋的发展、加强、减弱对应关系较好。水汽图像暗区前部依气旋的发展加强、维持、减弱而主要出现在黄淮气旋西侧、南侧和东侧。分析垂直环流表明,干侵入来自对流层中上层,与水汽图像暗区有较好的对应关系,在气旋发展强盛期下沉气流区自西向东、自南向北推进。高空动量下传促使地面气旋发展,从而使中、低层大气变得非常干燥。335K等熵面上的流场特征、等熵面陡峭处与水汽图像暗区的对应关系较好。θse的垂直剖面能反映干侵入特征。等熵面在垂直方向的折叠可使对流层中下层出现潜在对流不稳定区。θse=335K位温舌能较好地反映天气系统的三维结构和干侵入特征。自高层向下传递、加强的位涡变化能反映干侵入的动力特征。     

开合构造环境下花岗岩体的构造样式与变形差异

传统研究认为,大量花岗岩体的侵入发生于区域性伸展环境,是碰撞造山后应力松弛阶段侵位的,称之为造山后或非造山侵入体。近年来,对造山带和古岩浆弧的深入研究发现,花岗岩不但可以侵位于伸展构造环境,也可侵位于挤压构造环境(同构造侵入体),两者在三维空间形态、宏观尺度、露头尺度、显微尺度上的构造样式与变形往往是不同的。区分2类不同构造样式的岩体,对于分析区域构造和造山带演化有着重要的意义。     

论云南兰坪金顶超大型铅锌矿床的成因

在前人大量工作和资料积累的基础上,从成矿构造地质背景、容矿系统、容矿岩石的归属与成因、成矿时代和成矿物质来源方面论述了云南兰坪金顶超大型铅锌矿的成因,指出金顶超大型铅锌矿床是新生代陆陆碰撞造山背景下,在晚始新世至渐新世（大约33Ma）区域挤压推覆转变为区域拉张伸展构造环境转换时期,幔源岩浆和热流驱动盆山转换前被封闭在裂谷或前陆盆地深部富含油气、膏盐和金属的流体,沿着造山带两组伸展构造交汇部位上升,在构造圈闭环境下,通过角砾岩侵位—流砂底辟—流体排泄—金属淀积的产物。     

湘东板杉铺岩体构造样式与侵位机制

根据板杉铺岩体的基本特征 (形态、产状、主体单元的空间分布、接触关系 )、围岩构造 (褶皱、断层、片理等 )、内部构造 (片麻理、包体、断层、节理、岩脉、岩石磁性组构 )等构造样式认为 ,板杉铺岩体侵位经历了重熔岩浆的产生→底辟上升→多次脉动式上侵的逆旋—气球膨胀的过程 ,为花岗岩体构造样式研究与就位机制分析开拓了新的思路。     

Modelling of colloidal particle and heavy metal transfer behaviours during seawater intrusion and refreshing processes

The proper management of coastal aquifers commonly requires an understanding of regional mass flow and complete seawater–freshwater circulation. In this study, time series observations of seawater intrusion and refreshing were conducted using a column experiment based on natural flow conditions in coastal groundwater and a sampled medium from a coastal sandy aquifer without chemical treatment. Ranges of hydrodynamic and hydrochemical variables were tested and analysed. The results showed that the zeta potential of suspended colloids in aqueous solution in an aquifer polluted with 0.5 g/kg of heavy metals exhibited an isoelectric point for pH values ranging from 5.70 to 6.07 when freshwater or seawater completely occupied the aquifer pores, which is representative of natural hydrochemical conditions. In this scenario, a high background concentration of heavy metals induced colloidal immobilization. Otherwise, seawater–freshwater circulation enabled colloid mobilization due to ionic strength and pH fluctuations. The migration of multiple heavy metals occurred at a characteristic time of approximately 1 pore volume after each intrusion stage began and when the peak rate of colloid release was reached. At these times, the colloid behaviour determined the quantity and pathway of heavy metal transport. On the basis of the influences of seawater and freshwater interactions, the quantity of mobilized particles generally decreased and was uniformly distributed in each fraction due to particle loss and decreased porous connectivity. We speculate that the decrease in the total surface area of the migratory colloids may cause colloid‐associated heavy metal transport to decrease. The experimental results provide a useful basis for testing coastal groundwater flow and mass transport models because these phenomena require full characterization to precisely evaluate the associated fluxes from the field scale to the microscopic dimension.     

Coastal aquifer response to extreme storm events in Emilia‐Romagna,Italy

With global warming and sea level rise, many coastal systems will experience increased levels of inundation and storm flooding, especially along sandy lowland coastal areas, such as the Northern Adriatic coast (Italy). Understanding how extreme events may directly affect groundwater hydrology in shallow unconfined coastal aquifers is important to assess coastal vulnerability and quantify freshwater resources. This study investigates shallow coastal aquifer response to storm events. The transitory and permanent effects of storm waves are evaluated through the real time monitoring of groundwater and soil parameters, in order to characterize both the saturated and unsaturated portions of the coastal aquifer of Ravenna and Ferrara (southern Po Delta, Italy). Results highlight a general increase in hydraulic head and soil moisture, along with a decrease in groundwater salinity and pore water salinity due to rainfall infiltration during the 2 days storm event. The only exceptions are represented by the observation wells in proximity to the coastline (within 100 m), which recorded a temporary increase in soil and water salinity caused by the exceptional high waves, which persist on top of the dune crest during the storm event. This generates a saline plume that infiltrates through the vadose zone down to the saturated portion of the aquifer causing a temporary disappearance of the freshwater lens generally present, although limited in size, below the coastal dunes. Despite the high hydraulic conductivity, the aquifer system does not quickly recover the pre‐storm equilibrium and the storm effects are evident in groundwater and soil parameters after 10 days past the storm overwash recess.     

“5.8”桂东北暖区暴雨成因及漏报难点分析

利用常规天气图和数值预报资料,对2011年5月8发生在广西东北部的一次大范围较强降水过程的成因和预报失误的原因进行了分析,结果表明:高空波动和低空突然增强的南亚季风急流的共同作用,700～500hPa风切变引起的辐合上升以及干线入侵是造成这次强降水过程的主要原因。这次暴雨过程漏报的主要原因是:天气形势配置不是很有利,对中层干侵入的分析不够深入。     

大连市海水入侵现状与防治措施

海水入侵是沿海地区的环境问题之一。大连是我国北方重要的港口和工业城市．处于三面靠海的半岛地理环境。同时．大连也是一个水资源十分紧缺的城市。自20世纪70年代开采地下水以来．出现了越来越严重的海水入侵问题．海水入侵问题对当地的工农业生产、生态环境及人们的身体健康均造成了不同程度的影响。目前大连市的海水入侵问题已得到控制,基本处于稳定状态。提出了因地制宜的海水入侵防治措施。     

Porosity and microstructure characterization of building stones and concretes

The microstructure of building materials greatly influences engineering properties like permeability, strength and durability. To determine this microstructure, different techniques were developed, each with its own limitations. The purpose of this study on concrete and natural building stones was to compare and to combine data obtained by X-ray computed micro-tomography (micro-CT), water absorption under vacuum and mercury intrusion porosimetry (MIP). Pore-size distribution curves ranging from 10 nm to 1 mm and total porosity results were obtained. Furthermore, micro-CT revealed the presence of an interfacial transition zone (ITZ) and of micro-cracks inside the aggregates of the concrete samples after mercury intrusion. Micro-CT visualized mercury inside large air bubbles within the concrete samples. Both micro-CT and MIP were compared and their respective advantages and disadvantages discussed.