20世纪90年代国外花岗岩类研究的某些重 展

对20世纪90年代国外花岗岩类研究几个方面的进展情况进行了评述：I型／S型花岗岩成因的新模式、磁铁矿系列、钛铁矿毓花岗岩成因、从ISAM到以综合标志为基础的新的花岗岩地球动力学分类、从以大陆边缘板块俯冲带为主扩大到大陆内部碰撞造山带的花岗岩研究地域及太古宙TTG成因，并力图阐明提出问题和解决问题的思路及着手研究的途径。这些内容表明花岗岩研究已进入一个新的发展阶段，即从以个别岩体、央套为主的研究发展到对全球不同构造背景下的花岗岩进行地球动力学研究。作为地壳重要组成的花岗岩物质可以作为地球动力学环境的标志及其演化的示踪剂，反演出不同地球动力学环境下大陆地壳的形成和再循环过程。     

世界级贵金属和贱金属矿床的定量研究

迄今全世界已发现金１９．３万吨，其中６２％产于四个主要产金国，６８％产于四种主要金矿床类型银已发现１７４万吨，５５％产于四个主要产银国，４５％产于四种主要银矿床类型铜已发现１５．２亿吨，５６％产于四个主要产铜国，８８％产于四种主要铜矿床类型。     

Influence of aquifer properties on phytoremediation effectiveness

Recent research has shown that planting deep-rooted trees, such as poplar, can take up and degrade important ground water pollutants such as trichloroethylene (TCE) as they transpire water from the capillary fringe of shallow contaminated aquifers. The effect of hydrogeologic factors on the minimum plantation area needed to prevent downgradient migration of contaminated ground water is not well known. Accordingly, the objective of this research was to identify the hydrogeologic parameters that control phytoremediation effectiveness. We used a numerical ground water flow model to evaluate the effect that natural variations in hydrogeologic parameters and growing season duration have on the minimum plantation area required for capture. We found that the plantation area that was needed to completely capture a ground water contamination plume was directly proportional to aquifer horizontal hydraulic conductivity, saturated thickness, and ground water gradient. The plantation area needed for capture increased nonlinearly with increasing plume width, aquifer anisotropy, and decreasing growing season duration. The plantation area needed for capture was generally insensitive to aquifer-specific yield and storativity. Steady-state simulations can be used to predict the plantation area needed for capture in many applications. A particularly important finding of this work is that evapotranspiration fluxes through plantations appropriately sized to contain the plume substantially exceeded the ground water flux through the plume itself.     

河南鲁山太华群两为斜长角闪岩地球化学对比及其构造环境

河南鲁山早前寒武纪太华群中分布着两类斜长角闪岩：一类为正常斜长角闪岩,主要产于晚太古代下太华群荡泽河组;另一类为富钠斜长角闪岩,产于古元古代上太华群雪花沟组,两类岩石外表特征和矿物成分相近似,但化学成分明显不同,正常斜长角闪岩具较低的Ｎａ２Ｏ（１．９６％－２．８６％）,Ｋ２Ｏ（０．２４％－０．６４％）,Ｔｉ,Ｙ,Ｚｒ,Ｈｆ和∑ＲＥＥ含量,而富钠的斜长角闪岩以较高的Ｎａ２Ｏ（３．３１％－５．５０％）