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1.
本文的目的是提供介绍减少降雨派生的渗漏和流入的努力有效评估方法及目前的一些修复项目的结果。方法的解释是为那些准备和考虑对于修复结果的流量数据进行评估的人作为一个引物。方法的讨论范围从基本的线综述到风暴数据的评估及控件的使用。成为修复计划或是考虑实际工程的应用及他们的并发症。结果来源于被呈现的降雨派生的渗漏和流入的峰值的缩减范围从14%到61%及降雨派生的渗漏和流入的体积缩减范围从42%到70%的7个修复项目和阶段。  相似文献   

2.
现在提出了利用不同的参数来定量评价放射性异常的远景。这些参数有:测到的γ放射性的极大值,晕的含矿性和放射性异常的延拓。在所有的情况下,评价的可靠性取决于在代表性层面上进行的普查工作的可靠性。确定代表性层位埋深的一个因素是疏松沉积层的厚度。在山区森林的分水岭和山坡地区,疏松层的厚度一般为0.5至5.0米。由于所研究的各种山区森林的地形占有的面积为总面积的30—70%,所以评价疏松沉积物的厚度对用放射性测量γ  相似文献   

3.
含不同半径孔洞的颗粒体模型的力学行为数值模拟   总被引:3,自引:0,他引:3  
本文通过编程建立了非连续介质(颗粒体材料)模型,采用FLAC软件模拟了静水压力条件下不同半径的巷道围岩中的剪切应变增量、最小主应力及最大主应力的分布规律。研究表明,随着孔洞半径的增大,呈圆环形的剪切应变增量与最小主应力的高值区的圈数、呈辐射状的最大主应力的高值区的延伸范围及剪切应变增量的最大值都呈先慢后快的增长趋势。模型中最大的拉应力接近于在模型四周所施加的压应力,而最大的压应力约为所施加的压应力的5~10倍。模型内部的剪切应变增量、最小主应力及最大主应力的分布是高度不均匀的。具有较高的差应力的位置与具有较高的剪切应变增量的位置具有很好的一致性。  相似文献   

4.
红外吸收光谱是各种化合物的最重要的特征。根据化合物的红外吸收光谱,研究各种物质的结构和成分,已是重要的现代方法之一。随着仪器的不断改进和样品制备技术的日益完善,红外光谱在矿物学研究的应用上日趋广泛。不同的矿物有着不同的红外吸收光谱。单个矿物红外光谱的唯一性是鉴定矿物的主要依据。在光谱的红外区域被矿物吸收的射线的波长与晶体中分子或原子间的振动有关。  相似文献   

5.
何细华 《岩矿测试》2004,23(3):文后I-文后I
在热催化高温燃烧TOC分析中,我们所面临的最棘手的问题是如何避免气体流速的波动对检测结果的影响。而影响气体的流速有下列因素:①由于高温燃烧,短时间所产生的气体的快速蒸发;②由于样品基体的不同,所产生的流速的变化;③由于管路上堵塞所引起的流速的变化;④催化剂形状的变化,所引起的流速的变化。  相似文献   

6.
试论矿田断裂地球化学   总被引:4,自引:0,他引:4  
构造地球化学这株刚萌芽的幼苗正以其强大的生命力引起国内外地质工作者的重视.构造地质学是研究地壳运动规律的科学;地球化学则是研究组成地壳的化学元素——原子运动规律的科学.十分明显,这种宏观的岩块、地块的运动与组成它们的基本单位——原子的微观世界的运动之间必然存在着密切的内在联系.我们可以看到,世上的超基性岩都沿深断裂带分布;火山岩都出现在地壳的某些活动区;与岩浆活动有关的内生金属矿产大多和地壳一定的构造带息息相关,如智利、赞比亚和乌拉尔的铜矿带和我国南岭的稀有-有色金属矿带部是引人注目的例子.即使在一个矿床的形成过程中,不同的构造阶段亦常有不同的元素富集,而且这种构造-岩浆-矿液的发展演化往往具有十分明显的规律性.这些现象并非偶然的巧  相似文献   

7.
新世纪地球科学视野中的新技术和新方法(代序)   总被引:4,自引:0,他引:4  
从科学发展战略的角度 ,讨论了新技术、新方法在地球科学中的应用。新世纪的地球科学在新技术、新方法的应用方面呈现出鲜明的时代特色 ,即观测范围的扩大与观测能力的增强 ,多学科观测的海量数据的积累与地球观测系统的整合 ,不断增强的挑战非线性复杂地球系统中的预测问题的能力。特别是 ,作为地球观测系统的整合的“数字地球”和作为地球过程的模拟工具的高效并行计算 ,将在地球系统科学的发展中发挥重要作用。从方法论的角度 ,文中特别指出 ,只有掌握新技术、新方法的人对新技术、新方法有正确的理解 ,并具有创新性的思维 ,新技术、新方法才能发挥其应有的效能。  相似文献   

8.
探讨稀有金属的高温钠质交代岩形成时特定的构造条件积物理-化学特征。深成型的构造要素——变余压碎岩和变余糜棱岩——控制着具有同生的细粒浸染矿化的交代岩体的构造。岩石变形的程度,决定着高温的(650~600℃以上)携带钠的热液流的渗透作用的速度,控制着钠的浓度梯度的形成和交代分带性的扩散-渗透型的形成。  相似文献   

9.
泥浆的流动特性是泥浆的重要性质之一。它直接影响着循环的压力和泵的功率消耗,岩屑的携带和井内的清洁,地层压力的平衡和控制,钻头水马力的有效利用,井径的扩大或缩小,进而导致井内的复杂化、周期的延长和成本的升高。正如其他流体一样,要对泥浆的水力学行为进行研究,也必须首先搞清其基础力学性质,即在一定的外力作用下,流体是怎样发生变形和运动的。流体的这一应力与应变的关系,称为流变行为,而研究流体的流变行为的学科,称为流变学。不同的流体,可能  相似文献   

10.
信息价值论初探:关于矿产资源价值的理论思考   总被引:2,自引:2,他引:0  
信息价值论认为,凝结着人类劳动知识信息的自然资源、矿产资源是价值的有,人类的生产和消费活动既不能创造物质,也不能消灭物质,只是生产和消费信息的有序性,产品的价值是由产品信息的有序性决定的。而不是由投入的活劳动和物化劳动量决定的。产品的价格是由买卖双方共同认定的信息的有序性来决定。市场中价格背离价值的现象是因买卖双方占有信息的不对称所造成的。生产要素价值的本质是收入分配,以土地为代表的自然资源资本之  相似文献   

11.
Relative percentages of sand, silt, and clay from samples of the same till unit are not identical because of different lithologies in the source areas, sorting in transport, random variation, and experimental error. Random variation and experimental error can be isolated from the other two as follows. For each particle-size class of each till unit, a standard population is determined by using a normally distributed, representative group of data. New measurements are compared with the standard population and, if they compare satisfactorily, the experimental error is not significant and random variation is within the expected range for the population. The outcome of the comparison depends on numerical criteria derived from a graphical method rather than on a more commonly used one-way analysis of variance with two treatments. If the number of samples and the standard deviation of the standard population are substituted in at-test equation, a family of hyperbolas is generated, each of which corresponds to a specific number of subsamples taken from each new sample. The axes of the graphs of the hyperbolas are the standard deviation of new measurements (horizontal axis) and the difference between the means of the new measurements and the standard population (vertical axis). The area between the two branches of each hyperbola corresponds to a satisfactory comparison between the new measurements and the standard population. Measurements from a new sample can be tested by plotting their standard deviation vs. difference in means on axes containing a hyperbola corresponding to the specific number of subsamples used. If the point lies between the branches of the hyperbola, the measurements are considered reliable. But if the point lies outside this region, the measurements are repeated. Because the critical segment of the hyperbola is approximately a straight line parallel to the horizontal axis, the test is simplified to a comparison between the means of the standard population and the means of the subsample. The minimum number of subsamples required to prove significant variation between samples caused by different lithologies in the source areas and sorting in transport can be determined directly from the graphical method. The minimum number of subsamples required is the maximum number to be run for economy of effort.  相似文献   

12.
Summary Finite element analyses were conducted to investigate the magnitude of tensile strains imposed on landfill liners due to the formation of subsurface cavities. The study incorporated the significance of using geogrids to reduce the magnitude of strains and possibly the potential for collapse of landfill liners. Variations of key parameters included depth of overburden (D) and diameter of the cavity (B). Estimated stress distributions were compared to theoretical values obtained from a model reported in the literature. Results indicated that, contrary to conventional wisdom, the critical area based on the mechanics of arching was above the edge of the cavity where stress concentration occurred. Incorporation of geogrid reinforcement reduced the magnitude of tensile strains. The tensile force in the geogrid was dependent upon the size of the cavity, the depth of the overburden, and the applied pressure.  相似文献   

13.
The penetration of rigid objects such as piles and penetrometers into soils creates a zone of soil disturbance around them. The extent of this disturbed zone influences the resistance of the moving rigid body. This paper presents a theoretical framework to analyze the resistance in the disturbed zone created by a shaft penetrating a clay soil. The soil is modeled as a viscous material after it reaches failure [critical state (CS)]. The results of this analysis show that the viscous drag stress component on the shaft surface is influenced by the size of disturbed zone that has reached CS around the shaft, the shear viscosity of the soil and the velocity profile (or strain rate) in the CS zone around the shaft. The size of CS zone, the velocity profile and the viscosity of soil are interdependent. Large variation in viscous drag occurs when the size of the CS soil zone is less than four times the shaft’s radius. Limiting drag occurs when the size of the CS soil zone exceeds six times the shaft’s radius. The theoretical velocity distribution of the movement of soil in the CS zone shows that the soil is dragged along with shaft in the near field (close to the shaft surface) and moves upwards in the far field.  相似文献   

14.
文中描述了产自广西桂林地区下石炭统黄金组下部的颅形贝属一新种,桂林颅形贝(Cranaena guilinensis)。新种以平直的前结合缘和背壳上发育中槽为特征。在4枚标本上发现保存有放射状的彩色条带,表明该种当时生活在温暖海域的浅水环境。对该属70个种的地质地理分布和生物多样性变化的初步分析表明,该属可能起源于早泥盆世欧美大陆西北缘的老世界区,之后的地理分布和生物多样性发展以北美地区为中心,经历了中泥盆世—晚泥盆世早期和早石炭世2次比较明显的辐射演化、迁移扩散高峰和晚泥盆世晚期的1次严重衰退。第1次高峰是中泥盆世—晚泥盆世早期,该属的生物多样性达到巅峰,生物地理分布范围扩大到欧美大陆之外的西伯利亚板块、哈萨克斯坦板块和华南板块等;第2次高峰是早石炭世,该属的生物多样性虽不及前一次,但获得了最广泛的地理分布,不仅在北方大陆有分布,而且已进入到冈瓦纳大陆边缘。晚泥盆世晚期该属的1次严重衰退显然与F/F灭绝事件有关。早石炭世之后,该属进入衰退阶段,最终在二叠纪初灭绝。  相似文献   

15.
Stratigraphic units are defined and described for the Lower Carboniferous succession in the Walterstown-Kentstown area of Co. Meath, Ireland. A complete (unexposed) Courceyan succession from the terrestrial red bed facies of the Baronstown Formation to the Moathill Formation of the Navan Group has been penetrated in several boreholes. Although the lower part of the sequence is comparable with the Courceyan succession at Navan and Slane, the middle part of the sequence differs markedly in the Walterstown-Kentstown area and two new members, the Proudstown and Walterstown Members, are defined in the upper part of the Meath Formation. Syndepositional faulting was initiated during the Courceyan, probably in latest Pseudopolygnathus multistriatus or early Polygnathus mehli latus time. Movement on the ENE trending St. Patrick's Well Fault influenced the deposition of the Walterstown Member and the overlying Moathill Formation and was probably associated with the development of the East Midlands depocentre to the south of the area. A second episode of tectonism in the latest Courceyan or early Chadian resulted in uplift and erosion and the development of ‘block and basin’ sedimentation. Subsequent transgression of the uplifted block led to the establishment of the Kentstown Platform, bounded to the north, west and south by rocks of basinal facies. The Milverton Group (Chadian-Asbian), confined to this platform, unconformably overlies Courceyan or Lower Palaeozoic strata and is subdivided into three formations: Crufty Formation (late Chadian), Holmpatrick Formation (late Chadian-Arundian) and Mullaghfin Formation (late Arundian-Asbian). The Walterstown Fault controlled the western margin of the Kentstown Platform at this time. Contemporaneous basinal sediments of the Fingal Group (Lucan and Naul Formations) accumulated to the west of the Walterstown Fault and are much thicker than age-equivalent platform facies. Platform sedimentation ceased in latest Asbian to early Brigantian time with tectonically induced collapse and drowning of the platform; platform carbonates of the Mullaghfin Formation are onlapped northwards by coarse proximal basinal facies of the Loughshinny Formation. A distinct gravity anomaly in the Kentstown area suggests the presence of a granitoid body within the basement. The Kentstown Platform is therefore considered to have formed on a buoyant, granite-cored, footwall high analogous to the Askrigg and Alston Blocks of northern England.  相似文献   

16.
Shallow water platform limestones of the Chadian–Asbian Milverton Group are restricted to the north-eastern part of the Lower Carboniferous (Dinantian) Dublin Basin. Here, they are confined to two granite-cored fault blocks, the Kentstown and Balbriggan Blocks, known to have been active during the late Dinantian. Three areas of platform sedimentation are delimited (the Kentstown, Drogheda and Milverton areas), although in reality they probably formed part of a single carbonate platform. Resedimented submarine breccias and calciturbidites (Fingal Group) composed of shallow water allochems and intraclasts sourced from the platform accumulated, along with terrigenous muds, in the surrounding basinal areas. Sedimentological evidence suggests that the Kentstown and Balbriggan Blocks possessed tilt-block geometries and developed during an episode of basin-wide extensional faulting in late Chadian time. Rotation of the blocks during extension resulted in the erosion of previously deposited sequences in footwall areas and concomitant drowning of distal hangingwall sequences. Antithetic faults on the northern part of the Balbriggan Block aided the preferential subsidence of the Drogheda area and accounts for the anomously thick sequence of late Chadian platform sediments present there. Continued subsidence and/or sea-level rise in the late Chadian–early Arundian resulted in transgression of the Kentstown and Balbriggan Blocks; carbonate ramps developed on the hangingwall dip slopes and transgressed southward with time. Subsequent progradation and aggradation of shallow water sediments throughout the Arundian to Asbian led to the development of carbonate shelves. Several coarse conglomeratic intervals within the contemporaneous basinal sequences of the Fingal Group attest to periodic increases of sediment influx associated with the development of the shelves. Sedimentological processes controlled the development of the carbonate platforms on the hangingwall dip slopes of the Kentstown and Balbriggan Blocks, though periodic increases of sediment flux into the basinal areas may have been triggered by eustatic falls in sea level. In contrast, differential subsidence along the bounding faults of these blocks exerted a strong control on the margins of the late Dinantian shelves, maintaining relatively steep slopes and inhibiting the progradation of the shelves into the adjacent basins. Tectonically induced collapse and retreat of the platform margins occurred in the late Asbian–early Brigantian. Platform sediments are overlain by coarse-grained proximal basinal facies which fine upwards before passing into a thick shale sequence, indicating that by the late Brigantian carbonate production had almost stopped as the platforms were drowned.  相似文献   

17.
The explanation normally given for the tectonics of Sainte-Victoire Mountain, a dozen kilometres east of Aix-en-Provence, to the north of the limestone Provence, is incorrect. To the east, the morphology of the Sainte-Victoire is subdued, whereas to the west, before the mountain breaks savagely, the morphology is that of a young mountain as appears in Alpine landscapes. This unusual aspect in the region and the large subvertical faults with vertically striated surfaces that mark the massif to the south and to the west, induce the idea of strong vertical uplifts and caste doubt on the tectonic interpretation given in 1962 by Corroy et al. According to those authors, the Sainte-Victoire is a unit of Jurassic and Cretaceous formations overthrusting 1800 m to the south conglomerates of the Late Cretaceous or Palaeocene. New observations about the conglomerate transgression over the Jurassic and Cretaceous beds, and about the faults around and on the massif do not give evidence of an overthrusting but, on the contrary, induce the idea of a uplift, perhaps still active, in the form of a ‘piano key’ inclined to the northeast. To cite this article: J. Ricour et al., C. R. Geoscience 337 (2005).  相似文献   

18.
The evolution of the European Cenozoic Rift System (ECRIS) and the Alpine orogen is discussed on the base of a set of palaeotectonic maps and two retro-deformed lithospheric transects which extend across the Western and Central Alps and the Massif Central and the Rhenish Massif, respectively.During the Paleocene, compressional stresses exerted on continental Europe by the evolving Alps and Pyrenees caused lithospheric buckling and basin inversion up to 1700 km to the north of the Alpine and Pyrenean deformation fronts. This deformation was accompanied by the injection of melilite dykes, reflecting a plume-related increase in the temperature of the asthenosphere beneath the European foreland. At the Paleocene–Eocene transition, compressional stresses relaxed in the Alpine foreland, whereas collisional interaction of the Pyrenees with their foreland persisted. In the Alps, major Eocene north-directed lithospheric shortening was followed by mid-Eocene slab- and thrust-loaded subsidence of the Dauphinois and Helvetic shelves. During the late Eocene, north-directed compressional intraplate stresses originating in the Alpine and Pyrenean collision zones built up and activated ECRIS.At the Eocene–Oligocene transition, the subducted Central Alpine slab was detached, whereas the West-Alpine slab remained attached to the lithosphere. Subsequently, the Alpine orogenic wedge converged northwestward with its foreland. The Oligocene main rifting phase of ECRIS was controlled by north-directed compressional stresses originating in the Pyrenean and Alpine collision zones.Following early Miocene termination of crustal shortening in the Pyrenees and opening of the oceanic Provençal Basin, the evolution of ECRIS was exclusively controlled by west- and northwest-directed compressional stresses emanating from the Alps during imbrication of their external massifs. Whereas the grabens of the Massif Central and the Rhône Valley became inactive during the early Miocene, the Rhine Rift System remained active until the present. Lithospheric folding controlled mid-Miocene and Pliocene uplift of the Vosges-Black Forest Arch. Progressive uplift of the Rhenish Massif and Massif Central is mainly attributed to plume-related thermal thinning of the mantle-lithosphere.ECRIS evolved by passive rifting in response to the build-up of Pyrenean and Alpine collision-related compressional intraplate stresses. Mantle-plume-type upwelling of the asthenosphere caused thermal weakening of the foreland lithosphere, rendering it prone to deformation.  相似文献   

19.
以风火山流域某阴坡坡顶、 坡底和阳坡坡底活动层土壤水热及气象资料为基础, 对青藏高原多年冻土区不同地形条件下的土壤水热时空变化特征进行了分析。结果表明: 在融化阶段, 除表层5 cm外, 阴坡坡底各深度土壤开始融化日期均比坡顶早, 比阳坡坡底晚; 阴坡坡脚各深度土壤含水量均大于坡顶和阳坡坡底。在冻结阶段, 开始冻结日期在阴坡坡底均比坡顶早, 但比阳坡坡底晚; 阴坡坡底各深度土壤含水量均高于坡顶相应土层的含水量, 在20 cm、 100 cm、 160 cm深处高于阳坡相应土层的含水量, 但在5 cm、 50 cm深处, 稳定冻结后两者的含水量差异较小。在整个冻融过程中, 阴坡坡底土壤温度对气温变化的响应弱于坡顶及阳坡坡底, 但其土壤水分对降水的响应强于坡顶及阳坡坡底。植被生长发育受水分和热量条件的制约, 不同地形条件下水热时空变化差异将影响植被空间分布特征。在未来气候变暖情况下, 上坡位植被可能因为水分胁迫而退化, 出现荒漠化现象, 而下坡位由于受侧向流的影响, 土壤水分对降水的响应强烈, 植被不会发生显著退化; 在不同坡向之间, 同一坡位阳坡植被退化程度可能大于阴坡。  相似文献   

20.
渭河中游宝鸡-扶风段北岸塬边集中发育大型黄土滑坡,体积超过1 000×104 m3的滑坡达58处。在区域活动断裂调查、地球物理勘察、典型斜坡结构与构造调查基础上,研究了大型滑坡结构及其形成机理。研究表明:渭河北缘活动断裂以地堑式结构控制北坡塬边斜坡的地貌,主断裂面倾向南,倾角平均为68°,而次级断面结构组合控制斜坡结构,影响塬边大型黄土滑坡结构;塬边主断裂面与多个大型黄土滑坡后缘滑壁一致,断裂最大下挫距离7.1 m,影响大型滑坡的形态及发生过程;活动断裂呈地堑式结构,局部次级断面控制塬边多级滑动面的结构及其演化过程,如杨家村滑坡,局部滑坡剪出受断裂结构控制,剪出口角度可达72°,大部分剪出口未受到断裂面影响,角度平均为23°;三门组黏土岩黏粒体积分数超过35%,塑限平均值为23,是滑坡的层间剪切带;降雨诱发老滑坡复活是目前新滑坡发育的主要形式,大量的老滑坡形成于0.009 Ma BP二级阶地侵蚀期,而古滑坡形成于0.13 Ma BP三级阶地侵蚀期。  相似文献   

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