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查干德勒苏盆地铀成矿水文地球化学条件分析 总被引:2,自引:0,他引:2
本文在综述查干德勒苏盆地地质背景的基础上 ,阐述了盆地水文地质特征 ,并结合盆地地质演化史进行了古水文地质条件分析。根据层间氧化带砂岩型铀矿特征 ,从目的层空间展布、铀源、水文地球化学环境、水中微量元素、放射性水化学特征等角度提取了铀成矿信息 ,在盆地中部南缘圈定了一片铀成矿远景区。 相似文献
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《China Geology》2018,1(2):286-303
Nanogeology is a subject that is a combination of geology and nanoscale science, and it has been a frontier field in recent years. It is also a new subject with the features of intersectionality and multidisciplinary. Digging deeper into geological problems and nanoscale phenomena helps better revealing the more essential mechanisms and processes in geological science, which is also an evitable path in the development of geology. In this paper, we elaborate the concept, feature and main subdisciplines, and summarize three stages of nanogeology development from preliminary research in the 1990s to subject formation in China. After summarizing the researchers’ achievements in this field, we illustrate some primary research progresses of nanogeology in China as eight subdisciplines. On the basis of the above content, we propose the development prospect of nanogeology in China. There are many geologic problems with scientific values and economic benefits, such as research of geologic fundamental problems, resource exploration and development, mechanism study and prediction of geological activities (disasters), mechanism research and management of environmental pollution and others. Nanogeology has a great potential in China to solve all of these problems. As a result, the theories and methods of nanogeology will become enriching and advanced. It offers important theoretical basis and technological methods to deal with major issues concerning the national economy and the people’s livelihoods, such as the prediction of geological activities, as well as resource distribution and its exploration and utilization. 相似文献
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内蒙古中、上元古界地层的找金远景 总被引:11,自引:0,他引:11
内蒙古自治区境内,中、上元古界地层发育,其中所赋存的金属、非金属、贵金属矿产甚多。最近在中元古界朱拉扎嘎毛道组变质粉砂岩中所发现的微细浸染型金矿,是我局在元古界地层中寻找新类型金矿的一个突破,具有十分重要的意义。 相似文献
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粘性土微观结构研究回顾与展望 总被引:23,自引:1,他引:23
本文回顾了粘性土微观结构研究的发展历史, 分析了我国微观结构研究现状及存在问题, 展望了今后研究的发展趋势。 相似文献
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Theoretical aspects of cap-rock and fault seals for single- and two-phase hydrocarbon columns 总被引:6,自引:0,他引:6
Cap-rock seals can be divided genetically into those that fail by capillary leakage (membrane seals) and those whose capillary entry pressures are so high that seal failure preferentially occurs by fracturing and/or wedging open of faults (hydraulic seals). A given membrane seal can trap a larger oil column than gas column at shallow depths, but below a critical depth (interval), gas is more easily sealed than oil. This critical depth increases with lower API gravity, lower oil GOR and overpressured conditions (for the gas phase). These observations arise from a series of modelling studies of membrane sealing and can be conveniently represented using pressure/ depth (P/D) profiles through sealed hydrocarbon columns. P/D diagrams have been applied to the more complex situation of the membrane sealing of a gas cap underlain by an oil rim; at seal capacity, such a two-phase column will be always greater than if only oil or gas occurs below the seal.These conclusions contrast with those for hydraulic seals where the seal capacity to oil always exceeds that for gas. Moreover, a trapped two-phase column, at hydraulic seal capacity will be less than the maximum-allowed oil-only column, but more than the maximum gas-only column. Unlike membrane seals, hydraulic seal capacity should be directly related to cap-rock thickness, in addition to the magnitude of the minimum effective stress in the sealing layer and the degree of overpressure development in the sequence as a whole.Fault-related seals are effectively analogous to membrane cap-rocks which have been tilted to the angle of the fault plane. Consequently, all of the above conclusions derived for membrane cap-rocks apply to both sealing faults sensu stricto (fault plane itself seals) and juxtaposition faults (hydrocarbon trapped laterally against a juxtaposed sealing unit). The maximum-allowed two-phase column trapped by a sealing fault is greater than for equivalent oil-only and gas-only columns, but less than that predicted for a horizontal membrane cap-rock under similar conditions. Where a two-phase column is present on both sides of a sealing fault (which is at two-phase seal capacity), a deeper oil/water contact (OWC) in one fault block is associated with a deeper gas/oil contact (GOC) compared with the adjacent fault block. If the fault seal is discontinuous in the gas leg, however, the deeper OWC is accompanied by a shallower GOC, whereas a break in the fault seal in the oil leg results in a common OWC in both fault blocks, even though separate GOC's exist. Schematic P/D profiles are provided for each of the above situations from which a series of fundamental equations governing single- and two-phase cap-rock and fault seal capacities can be derived. These relationships may have significant implications for exploration prospect appraisal exercises where more meaningful estimates of differential seal capacities can be made.The membrane sealing theory developed herein assumes that all reservoirs and seals are water-wet and no hydrodynamic flow exists. The conclusions on membrane seal capacity place constraints on the migration efficiency of gas along low-permeabiligy paths at depth where fracturing, wedging open of faults and/or diffusion process may be more important. Contrary to previous assertions, it is speculated that leakage of hydrocarbons through membrane seals occurs in distinct pulses such that the seal is at or near the theoretically calculated seal capacity, once this has been initially attained.Finally, the developed seal theory and P/D profile concepts are applied to a series of development geological problems including the effects of differential depletion, and degree of aquifer support, on sealing fault leakage, and the evaluation of barriers to vertical cross-flow using RFT profiles through depleted reservoirs. It is shown that imbibition processes and dynamic effects related to active cross-flow across such barriers often preclude quantitative analysis and solution of these problems for which simulation studies are usually required. 相似文献
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甘肃省玄武岩的研究地学界多年来主要以火山岩地质调查为主,重点是对岩石的时空分布、岩石学、岩石地球化学及其成因和形成时代等方面进行的研究,而对玄武岩的开发利用目前仍停留在粗加工和低附加值产品上。根据国内目前对玄武岩纤维的开发应用前景,通过收集、整理与分析省内玄武岩的岩石化学资料,与玄武岩纤维化学成分推荐指标及国内外典型地区制造玄武岩纤维岩石化学成分对比,从理论上认为省内一些地区的玄武岩具有制造玄武岩纤维这种高附加值产品的可能性,并对其应用前景进行了分析。 相似文献