闽南区域地壳稳定性分区及其特征

通过一系列区域地壳稳定性背景资料的分析，以地壳结构、深断裂、活动断裂、第四纪升降速率、大地热流值、布格异常梯度、地壳应变能量、地震最大震级、基本烈度等综合指标，将闽南区域的地壳稳定性，自西而东划分为稳定区、基本稳定区和次稳定区。     

雅砻江锦屏水电站工程区活动构造研究及地壳稳定性评价

北东向的锦屏山-小金河断裂带从北东到南西斜穿整个锦屏水电站工程区。在它的东南和西北分别有北北西走向的羊坪子-纸厂沟断层组和北西走向的前波、高牛场等断层。锦屏山-小金河断裂带的马山头-周家坪断层组、瓦科断层组和北西向前波断层等晚第四纪继续活动, 但活动强度很弱。工程区新构造运动以整体抬升为主, 兼水平滑移和旋转运动。历史至今, 工程区地震活动微弱, 是地壳相对稳定的地区。     

某低中放废物处置预选区活动构造研究及地壳稳定性初步评价

本文对某低中放废物处置预选区的区域地质构造、活动断裂、新构造运动特征以及区域地震活动性开展了深入的研究。分析它们的基本规律和特征认为,该预选区新构造运动和地震活动均相对较弱。在此基础上,开展了区域地壳稳定性分区评价工作,认为该低中放废物处置预选区属地壳相对较稳定地区,可满足低中放废物处置场选址的要求。     

中国区域地壳稳定性评价简述

中国区域地壳稳定性评价是在首次编制的1:5000000中国区域地壳稳定性图基础上综述而成。      

基于模糊数学法的某低中放废物处置预选区地壳稳定性综合评价

本文基于模糊数学综合评价法选取断裂、地貌边界、地震、新构造单元和地球物理场等5项指标, 对某低中放废物处置预选区开展了地壳稳定性定量化评价, 在将研究区划分为8个不同稳定性区域的基础上, 认为该低中放废物处置预选区位于研究区内中部地壳稳定区域。     

珠江三角洲地壳稳定性分区及其特征

分析研究珠江三角洲地区的新构造运动、活动断裂、地壳厚度、地壳沉降、地热分布、地震活动等资料，其呈现出比较明显的空间分异。认为珠江三角洲区域稳定性划分为稳定区和次稳定区，区域地壳稳定性活动程度中等，次稳定区主体在地质构造区划上属于珠江三角洲断陷区及三角洲沿海区域，次稳定区范围之外的相对隆起地带为稳定区。     

哈尔滨地区地壳稳定性研究

客观评价城市区域地壳稳定性,对于城市安全与可持续发展有着极其重要的意义.哈尔滨城市地质调查系统地研究了哈尔滨地区的莫霍面深度、地球物理场、火成岩特征及历史地震记录,并开展大地电磁测深、钻探及汞气测量研究,认为哈尔滨地区地壳结构连续、完整、稳定,不会发生中等强度及以上地震活动.     

华北地块中部新构造运动

由于印度板块持续向北运动,引起青藏高原的挤出,并于中新世末引起华北地块的向东挤出。大约在7.3 Ma,太行山西侧渭河盆地唐县面首先解体,继而向北、向东发展;到5 Ma左右,太行山东麓断裂带的右行走滑,导致华北中部唐县面全面解体,形成多个太行山内部山间盆地,以及太行山西侧山西地堑系。这些断陷盆地的断陷幅度各不相同,太行山西侧山西地堑系断陷幅度较大,太行山内部山间盆地断陷幅度较小,太行山东部的渤海湾盆地断陷活动不明显。伴随着盆地的形成,太行山相对进入快速隆升阶段。山西地堑系控盆断裂以及太行山东麓断裂带第四纪以来仍存在明显活动,切割并控制第四系,局部在地表形成地裂缝。华北地块中部的应力场恢复以及深部构造分析表明,深部地幔上涌对浅部伸展构造的形成具有重要的影响,深部构造演变与浅部构造演变具有高度的一致性和耦合性。太行山东部渤海湾盆地自中新世以来就进入拗陷阶段,断裂活动弱,构造演化与西侧差异较大,表明这期构造运动动力源于西侧,太行山东麓断裂带作为两侧差异演变的边界,调节着两侧的差异构造活动。     

新构造运动对中国天然气成藏的控制作用

由于天然气扩散速率比石油快而不易保存,所以晚期成藏对天然气成藏来说有利于天然气的保存。新构造运动是中国构造史上最后一次大规模的造山运动,对天然气的成藏有着十分重要的控制作用。对于在晚期生气的烃源岩来说,新构造运动产生有效圈闭与晚期供气形成良好匹配,有利于天然气晚期成藏;对于早期成藏的天然气来说,新构造运动使气藏在纵向、横向发生调整,形成新的气藏,另外还可对部分气藏的储层进行优化、改造;新构造运动不仅使圈闭形成,并且还产生断裂系统,沟通烃源岩与储集层,导致幕式成藏,天然气充注效率提高,有利于天然气成藏;另外,新构造运动在构造强烈地区会对已形成的气藏起破坏作用。     

广州地区风化壳特征及其对城市建设的影响

文章划分了块状岩类、变质岩类、碎屑岩类、红色岩类、碳酸岩(石灰岩)类5类红色风化壳,宏观地叙述了各类红色风化壳的发育特征。介绍了各类风化壳的空间分布及其岩土性质,指出块状岩类风化壳、变质岩类风化壳、碎屑岩类风化壳一般分布于丘陵山体的斜坡上;红色岩类(红层)风化壳和碳酸盐岩类(石灰岩)的风化壳,一般埋藏于台地和平原的地面以下,以埋藏型风化壳为主。各类风化壳对城市建设环境的影响,并引发了边坡失稳、地面沉降、岩溶地面塌陷等灾害,分析了致灾因素。为城市规划建设、工程决策、灾害防治提供风化壳对城市建设环境影响的依据。     

Numerical modelling of dyke interaction and its influence on oceanic crust formation

Dykes are an essential element in building oceanic crust, most prominent in sheeted dyke complexes in the upper crust. Since dykes alter the magnitude and orientation of the local stress field, they cannot be treated as passive infillings of extensional fractures.We use a quasi-static, iterative 2-D boundary element method allowing for a wholesale movement of fluid-filled fractures. Effects of stress and pressure gradients, buoyancy and enclosed fluid mass are considered. The implications of the dyke-induced stress field are analysed combining the simulation of fracture propagation with computation of dyke interaction. Dyke interaction occurs by the adaptation of ascending dykes to the stress field caused by previous fractures arrested in the crust and leads to focussing and crossing of dykes. Examples for applications are introduced, concerning e.g. the generation of a magma chamber and the formation of the sheeted dyke complex. Our main results are that the interaction between dykes can be considerable and that the most important controlling factor is stress. The interaction is small when the horizontal tensional stress is large compared to the pressure in the dyke head. Otherwise, dykes tend to attract each other and to form centres of high dyke density or sill layers.     

Hydrochemical characteristics of groundwater in the Zhangye Basin, Northwestern China

The Zhangye Basin, located in arid northwest China, is an important agricultural and industrial center. In recent years rapid development has created an increased demand for water, which is increasingly being fulfilled by groundwater abstraction. Detailed knowledge of the geochemical evolution of groundwater and water quality can enhance understanding of the hydrochemical system, promoting sustainable development and effective management of groundwater resources. To this end, a hydrochemical investigation was conducted in the Zhangye Basin. Types of shallow groundwater in the Zhangye Basin were found to be HCO₃ ⁻, HCO₃ ⁻–SO₄ ²⁻, SO₄ ²⁻–HCO₃ ⁻, SO₄ ²⁻–Cl⁻, Cl⁻–SO₄ ²⁻ and Cl⁻ . The deep aquifer groundwater type was found to be HCO₃⁻–SO₄²⁻ throughout the entire area. Ionic ratio and saturation index calculations suggest that silicate rock weathering and evaporation deposition are the main processes that determine the ionic composition in the study area. The suitability of the groundwater for irrigation was assessed based on the US Salinity Laboratory salinity classification and the Wilcox diagram. In the study area, the compositions of the stable isotopes δ¹⁸O and δD in groundwater samples were found to range from −4.00 to −9.28‰ and from −34.0 to −65.0‰, respectively. These values indicate that precipitation is the main recharge source for the groundwater system; some local values indicate high levels of evaporation. Tritium analysis was used to estimate the ages of the different groundwaters; the tritium values of the groundwater samples varied from 3.13 to 36.62 TU. The age of the groundwater at depths of less than 30 m is about 5–10 years. The age of the groundwater at depths of 30–50 m is about 10–23 years. The age of the groundwater at depths of 50–100 m is about 12–29 years. For groundwater samples at depths of greater than 100 m, the renewal time is about 40 years.     

兖州煤田小构造发育特征及其对顶板稳定性的影响

讨论了兖州煤田3煤顶板小构造发育特征,重点分析了小断层发育的优选方位;然后分析了应力场作用下形成的4组不同性质的断裂构造,以及它们之间的相互关系;最后概论了不同性质小构造、不同类型组合以及出现在不同位置对煤层顶板稳定性产生的各种不同影响。     

Hydrochemical characteristics and salinity of groundwater in the Ejina Basin, Northwestern China

A hydrochemical investigation was conducted in the Ejina Basin to identify the hydrochemical characteristics and the salinity of groundwater. The results indicate that groundwater in the area is brackish and are significantly zonation in salinity and water types from the recharge area to the discharge area. The ionic ration plot and saturation index (SI) calculation suggest that the silicate rock weathering and evaporation deposition are the dominant processes that determine the major ionic composition in the study area. Most of the stable isotope δ¹⁸O and δD compositions in the groundwater is a meteoric water feature, indicating that the groundwater mainly sources from meteoric water and most groundwater undergoes a long history of evaporation. Based on radioactive isotope tritium (³H) analysis, the groundwater ages were approximately estimated in different aquifers. The groundwater age ranges from less than 5 years, between 5 years and 50 years, and more than 50 years. Within 1 km of the river water influence zone, the groundwater recharges from recent Heihe river water and the groundwater age is about less than 5 years in shallow aquifer. From 1 km to 10 km of the river water influence zone, the groundwater sources from the mixture waters and the groundwater age is between 5 years and 50 years in shallow aquifer. The groundwater age is more than 50 years in deep confined aquifer.     

Element Abundances of China‘s Continental Crust and Its Sedimentary Layer and Upper Continental Crust

China’s continental crust (CCC) has an average thickness of 47km, with the upper continental crust (CUCC) being 31 km and the sedimentary layer(CSL) 5 km in thickness. The CCC, CUCC and CSL measure 12.437 × 10⁻¹⁷, 8.005 × 10⁻¹⁷ and 1.146 × 10¹⁷ metric tons in mass, respectively. The mass ratio of the upper continental crust to the lower one is 1.8:1. The element abundances were calculated for the CCC, CUCC and CSL respectively in terms of the chemical compositions of 2246 samples of various types and some complementary trace element data. The total abundance of 13 major elements accounts for 99.6% of the CCC mass while the other minor elements only account for 0.4%. REE characteristics, the abundance ratios of element pairs and the amounts of ore-forming elements are also discussed in the present paper.     

墨翠的主要结构特征及其对透明度的影响

墨翠是翡翠中一个较特殊的品种,其主要的组成矿物为绿辉石.欧阳秋眉对其定义为由90%以上的绿辉石组成的单一矿物的玉石,具有反射光下呈黑色,透射光下呈绿色的特殊属性,并且具有较强的玻璃光泽.在近些年中,优质的墨翠以其具有细腻的质地、强玻璃光泽、反射光下深浓至黑的墨绿色、透射光下艳丽的绿色等特性受到市场和收藏者的追捧.本文探讨了墨翠的主要结构特征及其矿物颗粒大小、形态以及裂隙发育程度对墨翠透明度的密切影响.