Field Measurement of Suction, Water Content, and Water Permeability   总被引：1，自引：0，他引：1  

Alessandro Tarantino  Andrew M. Ridley  David G. Toll 《Geotechnical and Geological Engineering》2008,26(6):751-782

This paper presents a review of techniques for field measurement of suction, water content, and water hydraulic conductivity (permeability). Main problems in the use of field tensiometers are addressed and hints on how to improve tensiometer performance are given. Advantages and limitations of instruments for indirect measurement of suction including electrical conductivity sensors, thermal conductivity sensors, dielectric permittivity sensors, filter paper, and psychrometer are discussed. Techniques for water content measurement based on dielectric methods are then presented. These include time and amplitude domain reflectometry and capacitance. Finally, a brief overview of methods for measurement of water permeability in the field is presented.  相似文献   

贵州遵义牛蹄塘组黑色岩系的硒同位素变化及其环境指示初探   总被引：4，自引：0，他引：4  

朱建明  Johnson Thomas M  罗泰义  朱祥坤 《岩石矿物学杂志》2008,27(4):361-366

西南早寒武世牛蹄塘组是分布在中国南方扬子地台的一套黑色岩系,区域上发育有典型富集多金属元素的硫化物矿化层.选取遵义松林小竹牛蹄塘组下部富硒、钼、镍等元素的黑色岩系剖面,利用Se同位素初步探讨了该剖面岩石的沉积环境和硒的可能来源.结果表明,小竹牛蹄塘组下部剖面黑色岩系的δ82/76SeSRM3149比值变化较大,下部底层含碳斑脱岩与磷块岩的变化范围在-4.35‰～ 4.11‰之间;中间镍钼层及碳质页岩、碳质碳酸盐岩的δ82/76SeSRM3149变化范围窄,平均值为0.9‰±0.23‰(n=4);上层碳质页岩为-1.24‰.结合已发表的钼同位素数据,认为中间岩石沉积于缺氧/无氧环境,但存在盆地海水与热液或充氧水团的混合;下层的岩石曾一度位于充氧与贫氧环境的边界面,局部岩石曾暴露地表经历了较强的风化和蚀变作用,海水中硒有可能来自底部富硒斑脱岩的氧化淋滤或海底热液.据此推测遵义松林小竹牛蹄塘组下部岩石的沉积环境极可能处在局限盆地靠近陆地的边缘部分,经历了充氧→贫氧→缺氧/无氧→贫氧的演化阶段.  相似文献   

铁同位素的MC-ICP-MS测定方法与地质标准物质的铁同位素组成   总被引：22，自引：5，他引：17  

朱祥坤  李志红  赵新苗  唐索寒  何学贤  Nick S. Belshaw 《岩石矿物学杂志》2008,27(4):263-272

详细报道了在低分辨和高分辨模式下运用MC-ICP-MS进行Fe同位素比值高精度测试的方法,对Fe同位素测定过程中谱峰干扰、基质效应、浓度效应、仪器测试的长期重现性等问题进行了评估,并对两种运行模式的测试结果进行了对比.在95%的可信度范围内,所建方法的外部精度优于0.5ε/ainu,达到国际同类实验室的先进水平,并且低分辨和高分辨两种模式下获得的Fe同位素测试结果是一致的.在此基础上对国家地质标准物质GBW07105(玄武岩)和GBW 07111(花岗闪长岩)进行了Fe同位素测定.相对于Fe同位素国际标样IRMM-014,GBW07105的Fe同位素成分为:ε57Fe=1.9±0.3(20),ε56Fe=1.3±0.2(2σ),ε57/56Fe=0.6±0.1(2σ);GBW 07111的Fe同位素成分为:ε57Fe=1.8±0.4(2σ),ε56Fe=1.2±0.2(2σ),ε57/56Fe=0.6±0.1(2σ).  相似文献   

GEOPHYSICAL STUDIES OF WATER LEAKAGES FROM RESERVOIRS*     

A. A. OGILVY  M. A. AYED  V. A. BOGOSLOVSKY 《Geophysical Prospecting》1969,17(1):36-62

Considerable water leakages from reservoirs make it difficult to attain the planned storage capacity. In some cases water leakages give rise to suffusion followed by catastrophes. Until recently methods for locating water leakages were extremely imperfect. Geophysical methods offer good prospects in this direction. For solving these problems, it is effective to use streaming potential measurements, water flow rate observations and thermometry. Laboratory experiments were carried out in connection with the fact that water leakages from reservoirs are characterized by negative anomalies of natural currents; the more filtration discharge, the higher these anomalies are. As a result, the relationship governing the intensity of streaming potential and sand granulometric composition, electrolyte concentrations and other factors were revealed. To determine the velocity of water flowing to leakage sites, a special device, based on the relationship between the temperature of a heated body and its resistance, is applied. This device simultaneously makes it possible to measure the water medium temperature. Observations at reservoir sites were effected by moving along the reservoir non-polarizable potential electrodes and water velocity devices. Recordings were carried out automatically by the recording device of the logging apparatus. Under the conditions of ice cover on water surfaces, measurements were made through separate points by digging holes in the ice cover. Practical field observations were carried out at reservoir sites located in regions where fissured massive rocks as well as loose sediments predominate. In the first case field experiments were carried out in alpine reservoirs, in Armenia. The major water leakages were found to be concentrated on the right bank of the reservoir. In this connection it was not only possible to locate water leakage sites, but also to evaluate their relative intensity. These data were used for planning antifiltration measures. In the second case water leakages from a reservoir located in Uzbekistan in the submontane part of the Pamirs were studied. Streaming potential anomalies and high benthonic flow rates made it possible to discover high filtrations in the base and walls of the dam. Further perfection of these methods should not only permit the determination of water leakage sites and their relative intensity, but also filtration discharges in absolute units.  相似文献   

SOME EXPERIMENTS CONCERNING THE PRIMARY SEISMIC PULSE*     

P. N. S. O'BRIEN 《Geophysical Prospecting》1969,17(4):511-547

Recordings were made with three types of detector of the primary compressional (P) and shear (S) wave pulses generated by explosions in boreholes. Charge weights varied from 0.08 kg to 9.5 kg and detector distances varied from about 3 m to about 80 m. Scaling by the simple factor W^1/3 where W is the charge weight, enabled observations from different sized charges to be fitted to a single expression. Experiments were carried out in the Bunter sandstone and the London clay and both fluid and solid tamping were used. This variation in tamping had no significant effect on the P-waves but it may have affected the generation of SV-waves. In both media the P-wave energy carried at 30 m from the shot by frequencies less than 100 Hz decreased rapidly with depth and was usually 1–2 % of the available chemical energy for a shot depth of 15 m. The S-wave energy was much less than this, but was highly directional. The P-wave pulse had the appearance of a damped sinusoid in very good agreement with the predictions of the ‘equivalent radiator’ hypothesis. However, the surface of this radiator should be identified not with the blown cavity but with the surface at which the tensile stresses associated with the stress wave become less than the tensile strength of the rock. The predominant frequency for a 1 kg charge at a depth of 15 m was 24 Hz in the clay and 52 Hz in the sandstone. In these and similar media, therefore, an effort should be made to keep individual charges less than 1 kg in reflection shooting and less than 10 kg in refraction shooting. The value of Q was about 50 in clay and about 25 in the sandstone. These estimates are rather uncertain because of the small distances over which the pulses were observed. The Z-transforms of the sampled pulses indicated that they were all of minimum phase, or very near to it.  相似文献   

Ground-Water Studies— Chicagoland Deep Tunnel System     

Istavros S. Papadopulos  William R. Larsen  Forrest C. Neil 《Ground water》1969,7(5):3-15

  相似文献   

Lineages and Fractionation Trends in Undersaturated Volcanic Rocks from the East Otago Volcanic Province (New Zealand) and Related Rocks     

COOMBS  D. S.; WILKINSON  J. F. G. 《Journal of Petrology》1969,10(3):440-501

The petrology of the East Otago Volcanic Province (late Miocene),including the Dunedin Complex, is dominated by undersaturatedsodic lavas and shallow intmsives whose compositions range fromalkali basalt, basanite, and nephelinite to trachyte and phonolite.A range of relatively potassic volcanic rocks is also developedin the Province. The degree of undersaturation and ratios suchas (FeO+Fe₂O₃):MgO and K₂O:Na₂O vary widely in rocks with comparabledifferentiation indices. Chemical and mineralogical data onwhole rock-glass pairs and variants of shallow intrusives inthe Province, assessed in conjunction with similar data fromother volcanic provinces, demonstrate the production of trachyticliquids from alkali basaltic parents and of phonolitic liquidsfrom basanitic parents. Fractionation trends in both sodic andpotassic series, defined by variation in differentiation indexand normative nepheline, indicate that the degree of undersaturationof the derivative salic liquids is dependent on that of theparent; the slope of the fractionation trend lines is influencedby additional factors, including Po₂. The unequivocal productionof phonolite from trachyte in the East Otago Province has notbeen demonstrated. The mafic variants of theralites from Waihola and a basanite-pegmatoidassociation from Omimi are similar in composition, but the mostsalic differentiates from these differentiation sequences displaypronounced differences in their KO:Na₂O ratios, tending towardsleuco-theralitic (cf. lugarite) and malignitic compositionsrespectively. A multicomponent spectrum of fractionation lineages is suggestedfor individual differentiated bodies and for lava series. Sodiclineages include: (I) alkali basalt–hawaiite–mugearite–benmoreite–trachyte;(2) a more undersaturated series from basanite through nephelinehawaiite, nepheline mugearite, and nepheline benmoreite, tophonolite; (3) a nephelinite series, more restricted in compositionalrange. The relatively high Fe: Mg ratios characterizing themugearitic variants are sometimes exhibited by members of themore potassic series in which, however, Fe:Mg ratios tend tobe characteristically lower. This feature is correlated withthe frequent occurrence of kaersutitic amphibole or its resorptionproducts, indicative of intratelluric fractionation under relativelyhydrous conditions and probably relatively high Po₂. Certainnepheline trachyandesites from East Otago are described in detail.Trachy-basalt-trachyandesite-tristanite-trachyte and sanidinebasanite-nepheline trachyandesite-nepheline tristanite-phonolitelineages are also proposed, and the nomenclature of these moreseries discussed.  相似文献   

Mapping from Colour Aerial Photography     

W. G. Sims  M. L. Benson. 《The Photogrammetric Record》1969,6(33):321-324

  相似文献   

THE LAUSANNE CONGRESS     

G. R. Cooper  G. Petrie  A. D. N. Smith  M. Sowton  K. B. Atkinson 《The Photogrammetric Record》1969,6(33):239-258

The International Society for Photogrammetry held the Xlth International Congress at Lausanne during July 1968. The authors review the activities of five of the seven I.S.P. Commissions.  相似文献   

ROTATIONAL SLUMPS AND SLUMP SCARS IN SILURIAN ROCKS, WESTERN IRELAND     

M. G. LAIRD 《Sedimentology》1968,10(2):111-120

Curved or planar discordant surfaces occurring within a limited stratigraphic range immediately beneath shallow marine deposits represent penecontemporaneous shear surfaces along which slumps have moved. Rotated packets of strata frequently retained within the curved discordant surfaces show both internal and external evidence of having moved laterally. Movement is considered to have been triggered off by a sudden shock or shocks which may have been either of sedimentary or tectonic origin. The slumping occurred at the change in gradient between slope and shallow marine shelf deposits.  相似文献