北秦岭火山岩岩石化学特征和成因

北秦岭存在A、B、C三类火山岩系列,对应着幔源型、壳幔混染型和壳幔混合型成因类型。火山岩系列和成因类型的系统变化,反映了多旋回壳幔物质迁移特证。     

State of the art of modelling two-phase flow in fractured rock

 Two-phase flow in fractured rock is an important phenomenon for a range of practical problems, not the least of which is non-aqueous phase liquid (NAPL) contamination of groundwater. Although multiphase systems have long been studied in the petroleum field, in the hydrogeological field progress has only just reaches the point where models are being developed. Scale effect is one of the main issues of concern. Although models presented in this paper have the potential to provide useful predictions, they can only be used to investigate a variety of possible scenarios with parameters being specified in the form of distribution of values. The calibration and validation of all but the simplest of these models poses a formidable task, with great demands on hydrogeologists and geophysicists to provide adequate data. Received: 20 May 1996 · Accepted: 19 August 1996     

陕西驾鹿金矿床地质特征及成因探讨

驾鹿金矿床是小秦岭金矿带中一个比较特殊的矿床类型，产于古老韧性剪切带中，围岩蚀变强烈而广泛，尤其是成脉前的钾长石化。蚀变带及其中的石英脉控制了金矿体的产出，矿床属蚀变岩型金矿，成矿时代为燕山晚期．本文在论述矿床地质特征的基础上，通过稳定同位素研究，认为燕山期构造热事件是成矿的主导控制因素，成矿溶液来自大气降水，成矿物质则部分来自太华群，部分来自上覆中元古界高山河组，矿床成因属大气降水热液矿床．     

太阳软X射线观测进展

太阳软x射线观测在太阳物理的研究中，特别在日冕结构、磁场和日冕等离子体活动等物理现象的研究中起着重要的作用。太阳软x射线观测主要有光谱和成像观测两种．随着观测技术、方法和内容的发展，太阳软x射线观测揭示了太阳物理的许多重要的科学现象，并在预报、监测空间天气变化，预警空间灾变天气等方面也有着重要的应用．     

芝罘群岩石地层划分及区域对比

芝罘群分布于烟台市区北部芝罘岛、崆峒岛、担子岛等岛屿上,自下而上划分为老爷山组、兵营组及东口组.东口组为新建岩石地层单位.该群岩石组合为白云母钾长片麻岩、含电气石钾长石英岩、钾长石英岩、镜铁矿钾长石英岩、石英岩、白云母石英片岩夹黑云片岩、透辉变粒岩及大理岩等.其原岩为富钾、铁、硼的长英质碎屑岩夹粘土岩及富镁碳酸盐岩.兵营组单颗粒锆石U-Pb年龄为2171Ma,其成岩时代属古元古代早期.芝罘群区域上可与辽东地区古元古代榆树砬子群对比.     

辽宁省大石桥－吉洞峪一带辽河岩群变质地层的对比研究

辽宁省大石桥－吉洞峪一带出露的主要为古元古代的变质层状岩系，由云母片岩、长英质粒岩和大理类组成。区域上形成一大型北东向的复式向斜构造。复向斜南北两翼变质地层对比问题是辽吉东部辽河岩群研究的主要内容之一。作者根据五年来在大石桥－吉洞峪一带进行１∶５万区调所获得的新资料，从标志层及组合标志层、岩相学特征、主要标志层的岩石化学和稀土地球化学特征、变质作用演化等方面的研究入手，讨论了复向斜两翼变质地层对比的问题。结果表明，辽河岩群构成复向斜南北两翼的变质地层是完全可以对比的，从而进一步证实辽河岩群是一个不可分割的整体     

嵩箕地区登封群岩石地球化学特征

河南省嵩箕地区登封群变质杂岩，原岩为一套造山带和岛弧的中基性、少部分为酸性的火山岩组合。其中郭家窑组为基性，常窑组、石牌河组逐渐向酸性火山岩过渡，石梯沟组属正常沉积岩系列。该群微量元素丰度值与地壳克拉克值相比，普遍偏低，其中Ｒｂ、Ｓｒ、Ｂａ、Ｆ、Ｌｉ等元素明显偏低。     

A Generalized Backward Euler algorithm for the numerical integration of an isotropic hardening elastoplastic model for mechanical and chemical degradation of bonded geomaterials

An extended version of the classical Generalized Backward Euler (GBE) algorithm is proposed for the numerical integration of a three‐invariant isotropic‐hardening elastoplastic model for cemented soils or weak rocks undergoing mechanical and non‐mechanical degradation processes. The restriction to isotropy allows to formulate the return mapping algorithm in the space of principal elastic strains. In this way, an efficient and robust integration scheme is developed which can be applied to relatively complex yield surface and plastic potential functions. Moreover, the proposed algorithm can be linearized in closed form, thus allowing for quadratic convergence in the global Newton iteration. A series of numerical experiments are performed to illustrate the accuracy and convergence properties of the algorithm. Selected results from a finite element analysis of a circular footing on a soft rock layer undergoing chemical weathering are then presented to illustrate the algorithm performance at the boundary value problem level. Copyright © 2002 John Wiley & Sons, Ltd.     

矿山废石淋溶对水环境的影响

为了研究废石堆砌对水环境的影响,通过对废石做淋溶实验,分析了出入水的水质变化规律,对废石衍生环境效应的过程、机制、影响因素方面进行讨论,揭示了人们容易忽视的酸性水中硫酸根、总硬度、微量金属离子的动力学变化机理,指出矿山废石对水环境的污染不至限于使水质酸化,硫酸根、总硬度也会大幅度提高,废石堆放应充分考虑当地的地理气候及水文条件,合理堆放,减少污染。     

青田芝溪头鹤溪群浅变质岩系中发现动物化石

作者于1993年4月在浙江青田芝溪头鹤溪群剖面上采集了白云质大理岩标本样品，送南京地质古生物研究所进行标本浸泡处理。首次获得鱼骨、管状化石及土菱子介等海相化石，经鉴定认为其时代可能属石岩—二叠纪。本文根据以往的同位素资料、沉积环境分析和区域对比，认为这套变质岩系的原岩为二叠纪含煤沉积岩，可与福建的童子岩组中上部层位对比。