Study on Active Faults in Quaternary Unconsolidated Sediments by Microstructural Method

Active faults in Quaternary unconsolidated sediments are important indicators to determine paleoearthquake events,They can be studied by macroscopic geological survey,but some problems have been encountered,such as invisible active faults.The authors found an approach to solve these problems by microstructural observation.Firstly,oriented original-state samples of Quaternary Unconsolidated sediments in active fault zones are collected.Secondly,the samples are consolidated in laboratory.Thirdly,microstructureal slides are gound in three-dimension coordinate system.Lastly,microstructures are observed in the microscopic field.By this method,the movement properties of active faults can be determined in lack of the support of macroscopic data.The invisible faults in Quaternary unconsolidated sediments can be found and described.The mechanisms of die-out faults can be also studied.oreover,the boundaries between different unconsolidated sediments in engineering sites can be studied to judge whether they are active faults or not.     

第四纪松散沉积物中活断层滑动面的显微构造研究方法

第四纪松散深积物中的活断层滑动面是重要的古地震遗迹，也是鉴定古地震事件和确定古地震时代的重要标志。以往，以第四纪松散沉积物中活断层滑动面主要借助宏观观察进行研究，但遇到了一些难以解决的问题，如隐性断层问题。作者利用显微构造分析，找到了研究这些问题的途径，其方法是对第四纪松散沉积物进行定向原状样品采集，通过室内样品固结，显微薄片制作和显微构造现象观察等，从显微域里研究各种变形现象。用此方法，可以在没有宏观资料支持的情况下确定断面的运动性质；发现并描述第四纪松散沉积物中的隐性断层，研究断层的尖来机制，还可以对工程建设场地发现的不同松散沉积物相接触的现象进行活断层鉴别。     

Procedures for Sampling Deep Subsurface Microbial Communities in Unconsolidated Sediments

A corehole sampling project utilizing a wireline coring system provided sediment samples for microbiological characterization from deep unconsolidated sediments. Sampling tools were developed or modified to minimize contamination during sample acquisition and to facilitate stringent decontamination requirements. Quality assurance procedures, including the use of tracers, were implemented to minimize and quantify contamination from drilling hardware, drilling fluids and sample processing. Tracers included microspheres, potassium bromide, rhodamine dye, and perfluorocarbons, which enabled the detection and measurement of 1mg of drilling fluid per kg of sediment. In addition, sample processing was performed on-site in an anaerobic chamber to prevent exposure of the subsurface materials to atmospheric oxygen concentrations. Sediment samples were then disbursed to investigators at National Laboratories and universities funded through the Department of Energy Subsurface Science Microbiology Program for microbiological characterization. Results of these efforts demonstrated that representative subsurface samples were collected and disbursed.     

Drill-Through Casing Driver Drilling Method for Construction of Monitoring Wells in Coarse, Unconsolidated Sediments

Hole stability problems occurring during construction of monitoring wells in coarse, unconsolidated alluvium can be overcome by using a drill-through casing driver mounted on a standard top-head drive rotary rig. Steel casing is driven contemporaneously with drilling, providing continuous hole stability. Samples of aquifer material and ground water can be taken at discrete depths as drilling proceeds. Monitoring well completion is accomplished by: (1) using the steel casing as an open-ended piezometer; (2) installing a telescoping well screen; (3) plugging the casing end and perforating desired intervals, (4) installing one or more smaller diameter wells, and then (5) pulling back the steel casing. Advantages of this drilling method include maintenance of hole stability during drilling and well completion, faster borehole construction time than traditional methods in coarse alluvial deposits and other poorly sorted formations, and collection of representative samples of the geologic formations and ground water; additionally, drilling fluids are not required.     

Fracturing and Displacement Types of Active Faults in Unconsolidated Accumulative Materials and Their Implication for Timing Palaeoseismic Rupture Events

Seismic rupture produced by active faulting causes ground surface fracturing and seriously damages buildings.However,the fracture traces are usually indistinct or non-visible because of complicated deformations in Quaternary unconsolidated materials,so their upper parts can hardly be discovered on exploratory trenches.The aim of this paper is to study the types of fault rupture and displacement in different loose deposit beds from a joint view of mega-,meso-,and microscopic scales,and to find the mark and method for timing the palaeoseismic rupture on exploratory trenches.     

The Hydropunch™: An In Situ Sampling Tool for Collecting Ground Water from Unconsolidated Sediments

The Hydropunch™ is a stainless steel and Teflon® sampling tool that is capable of collecting a representative ground water sample without requiring the installation of a ground water monitoring well. To collect a sample, the Hydropunch (Patent #4669554) is connected to a small-diameter drive pipe and either driven or pushed hydraulically to the desired sampling depth. As the tool is advanced, it remains in the closed position, which prevents soil or water from entering the Hydropunch. Once the desired sampling depth is obtained, the tool is opened to the aquifer by pulling up the drive pipe approximately 1.5 feet (0.46m). In the open position, ground water can flow freely into the sample chamber of the tool. When the sample chamber is full, the Hydropunch is pulled to the surface. As the tool is retracted, check valves close and trap the ground water in the sample chamber. At the surface the sample is transferred from the Hydropunch to an appropriate sample container. The tool is a fast, inexpensive alternative for collecting ground water samples from a discrete interval. It is excellent for vertical profiling or defining the areal extent of a contaminant plume.     

浅水湖泊中沉积物碱性磷酸酶动力学参数的分布

东湖沉积物磷酸酶在较高的pH范围内表现出较高活性,故为碱性磷酸酶,东湖与严西湖沉积物中碱性磷酸酶的动力学参数表现出明显的空间异质性,且与间隙水和表层水中正磷酸根浓度无明显的对应关系,此外,它们在垂直方向上亦极具变化,除在沉积物表面显示较高催化效率之外,较沉层面（约距表面8－12cm)亦有类似峰值,这一结果补充说明了湖泊沉积物磷循环的另一活跃区域以及相应的生物化学机制。     

地球物理学与大陆成长

引言解释星球和原子的內部运动和活动情况的理論比关于地球的类似理論发展得更为完善,更广泛地为人接受,这是令人惊奇的。但如比較一下,地球比較容易接触到,而星球和原子則十分遙远,那么上述的情况应正好相反。这种情况之所以产生,一部分是由于許多星球和原子有強烈的輻射,因而透露出它們的性貭,一部分是由于原子和星球数量很多,因而我們有时可能对它們其中之一所发生的不寻常变化.     

A Study on the Tectonic Characteristics of Shallow Faults in the East of Zhengzhou City

Study on fault activity is a fundamental part of earthquake prediction and earthquake relief in big cities.In the active fault exploration in Zhengzhou,the spatial distribution,geological features and activity of the Huayuankou fault,the Shangjie fault and the Xushui fault were determined using the seismic prospecting method.New understanding about the characteristics of the faults was gained.This provides reliable basic data for future earthquake forecast and earthquake relief work in Zhengzhou.In addition,we proposed some ways to identify fault activity through analyzing the characteristics of the activity of a fault and raised an effective method for exploring active faults in big cities and exploring concealed faults in regions covered with thick overburdens.     

地球物理学与大陆成长

引言解释星球和原子的內部运动和活动情况的理論比关于地球的类似理論发展得更为完善,更广泛地为人接受,这是令人惊奇的。但如比較一下,地球比較容易接触到,而星球和原子則十分遙远,那么上述的情况应正好相反。这种情况之所以产生,一部分是由于許多星球和原子有強烈的輻射,因而透露出它們的性貭,一部分是由于原子和星球数量很多,因而我們有时可能对它們其中之一所发生的不寻常变化.     

第27届国际大地测量与地球物理学术会议及地震学和地球物理学领域进展

第27届国际大地测量与地球物理学术会议暨庆祝国际大地测量与地球物理联合会成立100周年活动于2019年7月8～18日在加拿大蒙特利尔召开。会议举办了各学科研讨会、联合研讨会和交叉学科研讨会,有关专家阐述了在地震学和地球物理学领域的关于地球深部结构探测、地外行星探测、地震预警等方面的研究进展,并开展了改选理事会、颁发奖励、评选会士等一系列活动。     

地球物理研究的国际动态

1卫星低频电磁辐射效应的研究 自从20世纪70-80年代利用卫星进行地球固有磁场测量以来,全球地磁场及其变化的测量中断了20余年时间.直到1999年2月丹麦航天局发射了奥尔斯太特2号卫星,又掀起地球磁场重力场测量热潮,推动了国际地球位场研究10年的活动(1998-2008年).     

特殊条件下的物探检测及其应用效果

长江三峡工程永久船闸高边坡卸荷影响带和清江水布垭导流洞洞壁松动圈对物探检测来说是两个极具代表性的工程问题．而地震波CT和声波测试又分别代表着最前沿和最常规的物探检测方法．本文应用地震CT和声波测试方法对上述两个问题进行了探测研究．探测结果表明,在解决某些特殊条件下的地质问题时,根据现场实际情况选定合适的地球物理方法可以取得事半功倍的效果．     

Guided Waves from Sources Outside Faults: An Indication for Shallow Fault Zone Structure?

— Using 3-D numerical modeling of seismic wave propagation we investigate the possibility of generating fault zone (FZ) trapped wave energy from sources well outside a fault. The FZ is represented by a O(200 m) wide vertical low velocity layer in a half space. We find that FZ trapped waves can be excited from sources well outside the fault if (1) the low-velocity structure extemds only to shallow depth and the source is located at greater depth or (2) the structure of the low-velocity zone is such that only the shallow part of the FZ traps energy. FZ trapped waves are not excited from sources well outside a FZ continuous with depth. The results support, in conjunction with recent observational evidence, a model for natural faults with shallow trapping structures rather than ones that span the entire seismogenic zone. This may have implications for fault mechanics as well as for aspects of shaking hazard near faults.     

Geoinformatics and Systems Analysis in Geophysics and Geodynamics

Izvestiya, Physics of the Solid Earth - The application of geoinformatics and systems analysis methods for processing and interpreting geospatial data in geophysics and geodynamics is considered....     

城市活断层的抗干扰高分辨率浅层地震勘探研究

首先，简要介绍了城市活断层探测的意义及世界各国开展城市活断层探测的基本情况。在简述抗干扰高分辨率浅层地震勘探基本原理的基础上，重点论述了城市活断层的抗干扰高分辨率浅层地震勘探的震源激发、数字地震仪性能、接收方式与接收条件、观测系统以及数据处理与资料解释等。研究表明，对于城市活断层的抗干扰高分辨率浅层地震勘探，在数据采集环节应采用具有线性或非线性变频扫描功能的可控震源和与其相匹配的地震仪器，以及小道间距、小偏移距、多接收道、短排列和高频检波器接收的工作方法；在数据处理与解释环节，要重视折射静校正技术、噪声压制技术、高精度速度分析技术、子波压缩技术、子波零相位化技术和叠前偏移技术等的应用。最后，给出了城市活断层的抗干扰高分辨率浅层地震勘探实例。