世界级金银铜铜锌矿床的定量分析

迄今为止，世界范围内已探明的资源总量，计金１９．３万吨，银１７４万吨，铜１５亿２千万吨，铅３亿４千９百万吨，锌７亿１千３百万吨。马上述所探明的每种金属堆积成立方体、则金，边长为２２ｍ的立方体；银，边长为５５ｍ的立方体；铜，边长为５５０ｍ的立方体；铅，边长为３１０ｍ的立方体；锌，边长为４６０ｍ的立方体。     

第二十九届国际地质大会简介

第29届国际地质大会于1992年8月24日到9月3日在日本京都国际会馆举行。来自全世界80多个国家和地区的4500余人与会。中国代表团250余人,仅次于东道国日本,其中以朱训部长为团长的官方代表团80人,受大会Geohost委员会资助的中青年代表35人,其他代表百余人。大会分三方面、25个学科,253个专题进行了广泛的学术交流(图1)。会议期间和会前会后又安排了34条地质旅行路线、66个科技展览、4个短训班、9个讨论会和两个讲座。大会取得了圆满成功,它将在推动地学的持续发展和人类合理开发利用资源,以及保护环境方面起到不可估量的作用。会议决定下一届大会于1996年在北京举行。     

Numerical examination of the factors controlling DNAPL migration through a single fracture

The migration of five dense nonaqueous phase liquids (DNAPLs) through a single fracture in a clay aquitard was numerically simulated with the use of a compositional simulator. The effects of fracture aperture, fracture dip, matrix porosity, and matrix organic carbon content on the migration of chlorobenzene, 1,2-dichloroethylene, trichloroethylene, tetra-chloroethylene, and 1,2-dibromoethane were examined. Boundary conditions were chosen such that DNAPL entry into the system was allowed to vary according to the stresses applied. The aperture is the most important factor of those studied controlling the migration rate of DNAPL through a single fracture embedded in a clay matrix. Loss of mass to the matrix through diffusion does not significantly retard the migration rate of the DNAPL, particularly in larger aperture fractures (e.g., 50 microm). With time, the ratio of diffusive loss to the matrix to DNAPL flux into the fracture approaches an asymptotic value lower than unity. The implication is that matrix diffusion cannot arrest the migration of DNAPL in a single fracture. The complex relationships between density, viscosity, and solubility that, to some extent, govern the migration of DNAPL through these systems prevent accurate predictions without the use of numerical models. The contamination potential of the migrating DNAPL is significantly increased through the transfer of mass to the matrix. The occurrence of opposite concentration gradients within the matrix can cause dissolved phase contamination to exist in the system for more than 1000 years after the DNAPL has been completely removed from the fracture.     

滇东早寒武世含磷岩系稀土元素地球化学特征及成因

滇东早寒武世含磷岩系稀土元素地球化学特征及成因杨卫东，漆亮，鲁晓莺（中国科学院地球化学研究所，贵阳５５０００２）关键词早寒武世，含磷岩，稀土元素，地球化学特征，成因我国南方早寒武世含磷岩系位于震旦系／寒武系的界线附近。该界线标志着地球发展历史中无机界...     

唐山矿井模拟与数字水位的记震能力对比分析

介绍了唐山矿井模拟水位与数字水位观测的基本情况,对2004年7月至12月11次全球7级以上地震引起唐山矿井模拟水位与数字水位水震波特征进行了对比分析。结果表明数字水位有较模拟水位的记震特征易识别,水震波初动清楚,资料连续,误差小等优点,但数字水位采样率低,水震波记录存在畸变。     

碳汇效应及其影响因素研究进展

碳中和现已成为全球共识。为实现碳中和目标,除了发展新能源降低碳排放外,提升固碳增汇能力是其重要途径。碳汇可分为海洋碳汇和陆地碳汇两大类。海洋碳汇包括沿海生态碳汇、海水生态碳汇和人工海洋碳汇。其中,沿海生态碳汇主要由海岸植被固碳效应和沿海沉积物负载形成,海水生态碳汇主要由海洋碳泵效应形成,这两种碳汇与季风洋流条件、陆源有机物输入、海岸地理条件和人为活动直接相关,人工海洋碳汇的可行性需要综合考虑对海洋生态的影响。陆地碳汇包括陆地植被碳汇、自然地质碳汇和人工地质碳汇。其中,陆地植被碳汇是通过森林植被、草地植被以及湿地植被等植物的光合作用实现,受气温与降水、大气成分、土地利用变化以及自然干扰等因素的影响。自然地质碳汇主要由土壤碳汇和岩石风化碳汇组成,土壤碳汇受区域植被条件、气候条件和土壤利用等因素影响,而碳酸盐岩和硅酸盐岩风化作用吸收大气CO₂的岩石风化碳汇主要受气温、降水、岩石类型、水文条件以及人类活动的影响。人工地质碳汇是将捕集后的CO₂注入地下指定区域进行长期封存形成,其封存能力受地质构造、储盖条件、地热、地层水动力、油气潜力和盆地勘探开发程度...