小秦岭地质构造新认识

本文初步厘定了小秦岭区域构造格局及其动力学背景，将小秦岭划分为两个次级构造单元，北部基底岩系上隆区（太华台拱）及南部盖层沉积区（金堆－卢氏台凹）。北侧紧邻渭河断凹。两者之间为一套古老糜棱岩代表的韧性剪切带所分隔，自中，新生代以来，该区处于伸展构造环境，中南部（金堆－卢氏台凹）、北部（渭河断凹）为多期拆离构造，中部（太华台拱）抬升，形成了“拆离－变质杂岩核”构造，该构造控制着本区的金矿。     

应用遥感技术划分芜铜地区地层

采用遥感技术及其图象资料，对地层影象进行系统解译、调绘验证，达到划分对比地层的目的，是一种新的技术途径和方法。本文重点介绍芜钢地区１／１．４万航片、１／２０万ＴＭ卫片数字图象处理的地层影象解译调绘的成果、经验和方法。     

数字处理技术在桩基动测中的应用

目前,国内桩基动测正由模拟记录方式向数字记录方式过渡,本文针对这一时期出现的一些技术问题,从推广应用数字处理技术的角度,系统地阐述了诸如数字滤波、非线性放大,倒频谱、频率细化等技术的应用方法,并以实例说明其效果,最后概要地介绍了笔者编写的实现上述技术的实用软件。     

地震磁异常和电阻率变化的主要事记

世界一些多地震国家如日、美、苏、中等国报道了许多地震磁电前兆的观测震例、理论分析与实验模拟、以及预报实践的结果,它们在地震预报研究及地球电磁现象探测中起到交流借鉴的作用。根据1965—1981年所发表的研究论文材料,按年代顺序以大事记和附表(还列入地电异常)形式,将地磁异常和电阻率变化这两方面的震磁电现象综合汇编介绍如下,以供参考。     

Chemical characterization of porewaters in an intertidal mudflat of the Seine estuary: relationship to erosion-deposition cycles

A seasonal field study was carried out in the Seine estuary to determine the chemistry of sediment porewaters using the 'peeper' technique and changes in the elevation of the mudflats using the 'Altus' technique. This approach allowed us to evaluate the release of nutrients and to link these releases to the sediment hydrodynamics. Our results show that nutrient and organic matter cycling in a Seine estuary mudflat exhibits a seasonal behaviour, which is mainly influenced by variations in hydrodynamics. Sediments, rich organic matter, were input during floods and they were mineralized during summer and autumn, releasing nutrients and dissolved organic carbon into the sediment porewaters. The nutrient release, including ammonium, is mainly linked to the mineralization of organic matter, while the release of phosphate is delayed. The delay could be the result of phosphate association with organic matter and/or its co-precipitation with calcium and iron.     

Aquifer vulnerability to pesticide migration through till aquitards

This study investigates the influence of key factors-mainly recharge rate and degradation half-life--on downward migration of the widely used pesticide mecoprop (MCPP) through a typical clayey till aquitard. The study uses the numerical model FRAC3Dvs, which is a three-dimensional discrete fracture/matrix diffusion (DFMD) numerical transport model. The model was calibrated with laboratory and field data from a site near Havdrup, Denmark, but the overall findings are expected to be relevant to many other sites in similar settings. Fracture flow and MCPP transport parameters for the model were obtained through calibration using well-characterized laboratory experiments with large (0.5 m diameter by 0.5 m high) undisturbed columns of the fractured till and a field experiment. A second level of upscaling and sensitivity analysis was then carried out using data on hydraulic head, fracture spacing, and water budget from the field site. The simulations of downward migration of MCPP show that MCPP concentration and mass flux into the underlying aquifer, and hence the aquifer vulnerability to this pesticide compound, is mainly dependent on the degradation rate of the pesticide, the overall aquitard water budget, and the ground water recharge rate into the aquifer. The influence of flow rate, matrix diffusion, and degradation rate are intertwined. This results in one to four orders of magnitude higher MCPP flux into the aquifer from aquifer recharge rates of 20 and 120 mm/yr, respectively, for no degradation and MCPP half-life of 0.5 yr. From a sensitivity analysis it was found that the range of MCPP flux into the aquifer varied less than one order of magnitude due to (1) changing fracture spacing from 1 to 10 m, or (2) preferential flow along inclined thin sand layers, which represent common conditions for the current and other settings of clayey till in Denmark and other glaciated areas in Europe and North America. The results indicate that for aquifers overlain by fractured clayey tills, the vulnerability to contamination with pesticides (pesticide flux into the aquifer) and other widespread agricultural contaminants is going to vary strongly in the watershed as a function of the distribution of aquitard water budget (flow rate) and aquitard redox environment (controlling contaminant degradation rates), even if the thickness of the till is relatively constant. DFMD modeling of cause-effect relationships within such systems has great potential to support decisions in planning, regulation, and contaminant remediation.     

Ground water/surface water interaction in a fractured rock aquifer

In a recent field study of ground water/surface water interaction between a bedrock stream and an underlying fractured rock aquifer, it was determined that the majority of ground water discharge occurred through sparsely located vertical fractures. In this paper, the dominant mechanisms governing ground water/surface water exchange in such an environment are investigated using a numerical model. The study was conducted using several conceptual models based on the field study results. Although the field results provided the motivation for the modeling study, it was not intended to match modeling and field results directly. In addition, the extent of capture zones for discharging or recharging fractures was explored. The results of this study are intended to provide a better understanding of contaminant migration in the vicinity of bedrock streams. Based on the numerical results, the rate of ground water discharge (or recharge) was found to depend on the aperture size of the discharging feature, and on the distribution of hydraulic head with depth within the fracture network. It was determined that the extent of both the capture zone and reverse capture zone for an individual fracture can be extremely large, and will be determined by the height of the stream stage, the fracture apertures of the network, and the hydraulic-head distribution within the network. Because both the stream stage and the hydraulic-head distribution are transient, the size of the capture zone and/or the reverse capture zone for an individual fracture may change significantly over time. As a result, the migration path for contaminants within the fracture network and between the surface and subsurface will also vary significantly with time.     

Excel在水准路线计算中的应用

结合水准测量计算原理和方法，利用Excel具有的的函数、计算功能，可以代替编程来方便、准确地计算出水准路线中各点的高程。并以实例检验其可行性。     

内蒙古东乌旗阿尔哈达银铅锌矿区地质、物化探特征及其找矿意义

在内蒙古东乌旗阿尔哈达矿区通过地质、物、化探综合手段进行找矿，取得了良好效果，现已发现3个成矿带，仅在Ⅰ号矿带就发现规模不等的矿体近20个，初步概算银、铅锌资源量已达到中型矿床规模。该矿区的找矿经验对在草原覆盖区开展找矿工作具有指导意义。