The pressure dependence of the zirconium-in-rutile thermometer

The solubility of ZrO₂ in rutile is strongly temperature-dependent and has been identified as a potentially powerful thermometer when the rutile coexists with an appropriate buffer assemblage, e.g. zircon + quartz. In combination with experimental data at 10 kbar, previous consideration of data on natural rutile has not identified a pressure dependence for the thermometer. However, the expected volume change as a result of substitution of the larger Zr⁴⁺ cation for Ti⁴⁺ suggests that the Zr content of rutile should decrease with increasing pressure. To investigate the pressure dependence of the thermometer, piston cylinder (at 10, 20 & 30 kbar) and 1 atm furnace experiments were performed in the system ZrO₂-TiO₂-SiO₂. The solubility of ZrO₂ in rutile, in the presence of zircon and quartz was reversed at each pressure value. From these experiments, the thermodynamics of the end-member reaction ZrSiO₄ = SiO₂ + ZrO₂ (in rutile) have been determined. There is a secondary pressure effect accompanying the primary temperature dependence of the Zr content of rutile. New thermometer equations are, in the α -quartz field: in the β -quartz field and in the coesite field in which φ is ppm Zr, P is in kbar and R is the gas constant, 0.0083144 kJ K⁻¹. Thermometric results using these equations are shown for a range of geological settings.     

水库渗流影响文物遗址安全发掘研究——以湖南里耶秦代古城遗址为例

与古遗址相邻的江、河由于后期的工程活动,如水库、大坝的修建和蓄水,水位上升,将对遗址区地下水的运动规律及渗流场产生较大影响。在其影响下,古遗址可能产生各种环境地质灾害并对其发掘安全产生不利影响。论文以国家重点文物——湖南里耶秦代古城遗址安全发掘深度研究为例,在分析水库蓄水诱发的环境地质灾害的基础上,对遗址在不同库水位下的安全发掘深度及发掘方案进行了研究,提出了保障发掘安全的工程措施。研究成果为国家重点文物的保护和进一步发掘提供了科学依据。对类似文物工程的保护和发掘具有借鉴意义。     

三维地质模型的建立——以阿尔及利亚Zarzaitine油田为例

对阿尔及利亚Zarzaitine油田储层岩芯进行观察与描述,在沉积特征综合分析的基础上,结合岩芯的分析化验资料、测井和区域地质背景资料,根据沉积微相和电相之间的对应关系研究,划分出了各小层沉积微相。从沉积微相的分布特点,分析了该区储层(F4)沉积微相的空间演化规律,进而建立了该油田储层(F4)的三维地质模型。     

凤山县地质灾害统计分析及预报方法

通过对凤山县地质灾害统计分析，提出了降雨是诱发地质灾害的主要因素，建立地质灾害气象条件等级预报的简易方法。     

Structural control of the morphometry of open rock basins, Kananaskis region, Canadian Rocky Mountains

The morphometry of chutes (couloirs), rock funnels, and open cirques are related to the structure of dissected rock masses in the Kananaskis region of the Canadian Rocky Mountains. Data for ten morphometric variables were derived from digital elevation models of 56 open rock basins. The basins were classified structurally according to the relative orientations of bedding planes and the rock slopes. A hypothesis of no differences in morphometry among structural classes is rejected from the results of nonparametric analysis of variance and paired comparisons of rank scores. Basins on dip and overdip slopes have a distinct size, and those on anaclinal slopes have a distinct width and shape. Variation in morphometry from low compactness and area/relief (chutes) to high compactness and low area/relief (funnels) to high compactness and area/relief (open cirques) corresponds to a change in dominant structure from orthoclinal to dip-overdip to underdip to anaclinal. The dip of bedding planes relative to the slope of rockwalls controls the mode of initial displacement of joint blocks and, thereby, the spatial distribution of the retreat of rockwalls. The angle between the rock slope and the strike of dipping strata determines whether beds of differing stability form chutes and buttresses (orthoclinal slopes), or extend across rockwalls (cataclinal and anaclinal slopes) and retreat at similar rates to form funnels and open cirques. The optimal structure for large compact rock basins is anaclinal, and the least favourable is cataclinal dip-overdip slopes. Topoclimate and other geologic structures may account for variance in morphometry not explained by differences among structural classes.     

反射系数K法在地质灾害评价中的应用

应用电阻率测深法探测滑坡和塌陷,采用反射系数K法区分滑坡和塌陷的类型和性质,正确地评价地质灾害,为治理工作提供快速准确的地质依据。     

Reconstruction of natural groundwater flow paths in the multiple aquifer system of the northern Negev (Israel), based on lithological and structural evidence

 The Judea Group, a limestone and dolomite karstic aquifer of late Albian–Turonian age, is one of the most important sources of water in Israel. In the western part of the country, the Judea Group aquifer is also known as the Yarkon–Taninim basin. In the northern Negev, the Judea Group is a recipient for fresh water flowing southward from the Hebron Mountains and of brackish paleowater flowing northward from Sinai. Very little is known of the hydraulic properties of this aquifer. In order to outline assumed natural flow paths that existed in this karstic environment prior to groundwater exploitation, use was made of lithological, structural, and paleomorphological features. A detailed hydrogeological conceptual model of the Judea Group aquifer in northern Negev was established by the geological interpretation of high-resolution seismic reflection and by analysis of lithological evidence from boreholes. Isopach, isolith-contour, and isolith-ratio maps were compiled for the main lithological components. Increase in transmissivity values is inversely proportional with the cumulative thickness of argillaceous components. The lithological and hydraulic evidence provides the basis for subdividing the subsurface into distinctive permeability zones for the upper and lower sections of the aquifer; for outlining possible preferential groundwater flow paths for both subaquifers; and for improving understanding of groundwater-salinty variations that result from lithological variability, direction of groundwater flow paths, groundwater flow rates, and the duration of rock/water interactions. In an earlier conceptual model of the basin, the Judea Group aquifer was regarded as a continuous and undisturbed entity. The present study reveals an intricate groundwater flow pattern that is controlled by lithological and structural factors that create zones of preferential flow. This interpretation bears on the overall evaluation of groundwater resources and their management and exploitation. Received, December 1996 · Revised, October 1997, June 1998 · Accepted, July 1998     

Some current methods to represent the heterogeneity of natural media in hydrogeology

We have known for a long time that the material properties of the subsurface are highly variable in space. We have learned that this variability is due to the extreme complexity and variation with time of processes responsible for the formation of the earth's crust, from plate tectonics to erosion, sediment transport, and deposition, as well as to mechanical, climatic, and diagenetic effects. As geologists, we learned how to "read" this complex history in the rocks and how to try to extrapolate in space what we have understood. As physicists, we then learned that to study flow processes in such media we must apply the laws of continuum mechanics. As mathematicians using analytical methods, we learned that we must simplify by dividing this complex continuum into a small number of units, such as aquifers and aquitards, and describe their properties by (constant) equivalent values. In recent years, as numerical modelers, we learned that we now have the freedom to "discretize" this complex reality and describe it as an ensemble of small homogeneous boxes of continuous media, each of which can have different properties. How do we use this freedom? Is there a need for it? If the answer is "yes," how can we assign different rock-property values to thousands or even millions of such little boxes in our models, to best represent reality, and include confidence levels for each selected rock property? As a tribute to Professor Eugene S. Simpson, with whom the first author of this paper often discussed these questions, we present an overview of three techniques that focus on one property, the rock permeability. We explain the motivation for describing spatial variability and illustrate how to do so by the geostatistical method, the Boolean method, and the genetic method. We discuss their advantages and disadvantages and indicate their present state of development. This is an active field of research and space is limited, so the review is certain to be incomplete, but we hope that it will encourage the development of new ideas and approaches.     

基于DS1624的多点温度监测系统

为了减少温度变化对高精度时间比对的影响,设计了一种由带存储功能的数字温度计DS1624构建的、基于I2C总线的温度监测系统,并给出了系统的构成及软件、硬件实现方法和详细实验结果。分析表明,以温度监测系统为关键部分的温度控制系统是高精度时间比对所必要的。     

应用KDD技术分析气象地质灾害与降水的关系

应用人工智能技术——数据库中知识发现(KDD)技术,分析研究发生在云南省境内造成重大损失的气象地质灾害的发生与当日及前期降水的关系。结果表明,绝大多数气象地质灾害都是由强降水诱发的,云南气象地质灾害与发生当日及前期降水的关系主要有3种类型,即暴雨诱发型、多日中大雨诱发型和连阴雨诱发型。所得到的云南气象地质灾害与当日及前期降水的定量关系,为云南地质灾害的气象监测、预报模式的建立提供了依据。