The polarizability of sand-gravel deposits according to the results of laboratory and field measurements

2019 ◽  
Vol 13 (1) ◽  
pp. 68-77
Author(s):  
V. A. Kulikov ◽  
S. A. Anoshina
Keyword(s):  
Water Saturation ◽  
Field Measurements ◽  
Field Work ◽  
Induced Polarization ◽  
Electrical Tomography ◽  
Geophysical Model ◽  
Electrical Survey ◽  
Kaluga Region ◽  
2D Data ◽  
Sand And Gravel

Тhe article describes electrical exploration aimed at studying the polarizability of sand-gravel deposits in the Kaluga region. On the one hand, laboratory tests of the polarizability of sand and sand-gravel mixes (SGM) were carried out, on the other hand, field electrical survey work on the wellknown manifestation of SGM. Samples of SGM were collected from 18 actively operating quarries in the Moscow and Kaluga regions for laboratory petrophysical measurements. Induced polarization (IP) measurements were conducted in time domain. The results showed that sand and gravel mixes are characterized by a rapid process of induced polarization. The minimum values are associated with pure sand samples and the level of polarizability increases with increasing gravel content in the sample. The maximum values of polarizability are achieved when the moisture content of samples is 1,5–2,5%, however SGM samples polarized stronger than pure sand samples all over the moisture range. The field work was performed by the method of vertical electrical soundings with measuring of IP along the well-known sand and gravel deposits in the Kaluga region. The profile step and spacing of the electrical survey installation are selected in such a way as to use the same grounding locations many times. A similar approach is used for multichannel measurements of electrical tomography and allows for further 2D data inversion. The induced polarization was measured in the frequency domain in the frequency range from 0.15 to 19 Hz. The results of the multi-frequency inversion showed the differentiation of the section by the time parameter τ. According to inversion data the geological-geophysical model was constructed. In the section, zones of increased polarizability associated with a gravel-pebble fraction, as well as zones with partial water saturation of sediments were identified. Thus, under the certain favorable conditions, the IP method allows to delineate zones enriched with gravel-pebble fraction within the SGM deposit.

scholarly journals The results of using method of the VES-IP at studying sand-gravel mixtures on the territory of Mosalsky district of Kaluga region

2016 ◽  
pp. 52-58
Author(s):  
V. A. Kulikov ◽  
S. A. Anoshina ◽  
A. V. Solovieva
Keyword(s):  
Traditional Method ◽  
Thick Layer ◽  
Induced Polarization ◽  
Clay Particles ◽  
Equivalent Models ◽  
New Methods ◽  
Electrical Sounding ◽  
Kaluga Region ◽  
Sand And Gravel ◽  
Selection Of

Vertical electrical sounding is a traditional method of exploration of sand-gravel mix deposits. At present geophysicists are challenged not only to discover of the as-dug gravel, but also to determine its basic properties, allocate within the deposits plots with high percentage of gravel or determine the content of clay particles in the sands. To meet these challenges it is necessary to use new methods, in particular, the method of induced polarization. The paper presents the results of DC/IP surveys executed in the territory of Mosalsky district of Kaluga region in 2015. The work was carried out as already known, developed fields of sand-gravel mix deposits, as well as new search areas, which have not yet conducted drilling works. As shown by the results all the deposits of sand-gravels are characterized by high values of induced polarization. The complex selection of the curves of apparent resistivity and apparent polarizability substantially narrows the boundaries of equivalent models in the interpretation of data in complex geological situations where sand and gravel deposits slightly different from the surrounding rocks or covered with a thick layer of conductive loam.

scholarly journals Measurement of unsaturated meltwater percolation flux in seasonal snowpack using self-potential

2021 ◽  
pp. 1-16
Author(s):  
Wilson S. Clayton
Keyword(s):  
Method Development ◽  
Water Saturation ◽  
Field Measurements ◽  
Time Domain Reflectometry ◽  
Electrode Spacing ◽  
Glacier Mass Balance ◽  
Wetting Front ◽  
Electrical Field Strength ◽  
Water Redistribution ◽  
Self Potential

Abstract This paper presents a feasibility study of in situ field measurements of unsaturated meltwater percolation flux within the vertical profile of a snowpack, using the self-potential (SP) method. On-site snowmelt column tests calibrated the SP measurements. The SP data measured electrical field strength with an electrode spacing of 20 cm, and coincident water saturation (Sw) measurements using time domain reflectometry allowed calculation of SP-modeled vertical percolation flux (qsp), expressed as Darcy velocity. The results reflected transient diurnal snowmelt dynamics, with peak flux lagging arrival of a saturation wetting front. Peak daily qsp was 60 to >300 mm d−1, whereas daily snowmelt was 20–50 mm w.e. Surface refreezing events appeared to cause upward flow, possibly representing water redistribution toward the freezing boundary. Calculated fluxes were comparable to actual fluxes, although average errors ranged from −15 to +46% compared to average of melt expected from surface energy-balance and ablation stake measurements. By advancing method development to measure unsaturated meltwater percolation flux in snowpacks this study creates opportunities to study fundamental snowmelt processes, may improve mathematical modeling and may supplement glacier mass-balance studies and studies of snowmelt interactions with avalanches, groundwater and surface water.

DETECTION OF FRACTURED AQUIFER USING COMBINATION OF RESISTIVITY AND INDUCED POLARIZATION ANALYSIS

2015 ◽  
Vol 76 (15) ◽  
Author(s):  
Mohamed Azwan Mohamed Zawawi ◽  
Noorellimia Mat Toridi ◽  
Aimrun Wayayok
Keyword(s):  
Clayey Soil ◽  
Induced Polarization ◽  
Polarization Analysis ◽  
Fractured Aquifer ◽  
Low Resistivity ◽  
Groundwater Occurrence ◽  
Electrical Survey ◽  
Geological Formation ◽  
Subsurface Resistivity

Subsurface geological formation is essential in investigating the groundwater occurrence. The formation can be determined from subsurface resistivity value through electrical survey. However, there is ambiguity in interpreting the subsurface resistivity. Therefore the purpose of this study is to delineate the subsurface geological formation through combination of resistivity and induced polarization analysis. The type of geological formation is determined from resistivity analysis and well lithology. Meanwhile the fracture, water in clayey soil and groundwater occurrence is identified through combination of resistivity and induced polarization analysis.  It has been identified that the study areas consist of fractured aquifer. Possible groundwater fractured area can be indicated by low resistivity ranged from 700 to 2000 Ωm and overlapped with low chargeability ranged from 1 msec to 2 msec. This study provides useful information on nature of groundwater occurrence especially fractured aquifer.

A GEOPHYSICAL CASE HISTORY OF THE LAKESHORE ORE BODY

Geophysics ◽  
1971 ◽  
Vol 36 (6) ◽  
pp. 1232-1249 ◽  
Author(s):  
Philip G. Hallof ◽  
Emil Winniski
Keyword(s):  
Direct Detection ◽  
El Paso ◽  
Geophysical Methods ◽  
Field Measurements ◽  
Induced Polarization ◽  
Copper Ore ◽  
Ore Body ◽  
Ore Mineralization ◽  
History Of ◽  
Geophysical Technique

The Lakeshore ore body is in Pinal County, Arizona about 30 miles south of Casa Grande. In February, 1969 when the latest figures were published, the ore reserves were reported at 241 million tons of disseminated sulfide ore (0.7 percent copper) and 24 million tons of concentrated metallic ore (1.69 percent copper). Sulfide copper ore was first intersected in July, 1967 in Hole P‐3. The magnetite‐pyrite‐chalco‐pyrite mineralization occurred in a banded tactite at a depth of 1147 ft. Hole P‐3 was the fourth of several holes that were drilled to determine the source of an induced polarization anomaly that had been outlined, at depth, to the west of the old Lakeshore pit. The successful conclusion of this exploration program by El Paso Natural Gas Company is an excellent example of an integrated exploration approach. The application of regional geological planning, geophysical methods, and detailed geological reasoning resulted in the discovery of a major copper ore body. Due to the depth of the ore zone and the disseminated character of most of the ore, the only geophysical technique that was useful in the direct detection of the ore mineralization was the induced polarization method. Field measurements were made sporadically between August, 1966 and July, 1968. Variable‐frequency induced‐polarization measurements, made using the dipole‐dipole electrode configuration and electrode intervals from 300 ft to 1000 ft, successfully indicated the presence of the metallic mineralization at depth and gave some indication of its extent. Comparisons of the induced polarization data and the appropriate geological sections give information concerning the usefulness of the method.

RECENT ADVANCES AND APPLICATIONS IN COMPLEX RESISTIVITY MEASUREMENTS

Geophysics ◽  
1975 ◽  
Vol 40 (5) ◽  
pp. 851-864 ◽  
Author(s):  
Kenneth L. Zonge ◽  
Jeffrey C. Wynn
Keyword(s):  
Host Rock ◽  
Electromagnetic Coupling ◽  
Field Measurements ◽  
Complete Removal ◽  
Induced Polarization ◽  
Laboratory Measurements ◽  
Spectral Measurements ◽  
Complex Resistivity ◽  
Geophysical Interpretation ◽  
Rock Alteration

Several years of accumulating complex resistivity spectral measurements have indicated that there are still many unexplored areas in induced polarization surveying that need to be investigated for a more complete understanding of the polarization process. In addition to providing mineral discrimination capabilities, complex resistivity spectra can be used to differentiate between various barren host rock responses, to facilitate the complete removal of electromagnetic coupling, and to identify pipeline, fence, and various other cultural coupling effects. Results of field measurements are presented in an effort to demonstrate the utility of and necessity for making complete spectral measurements for serious geophysical interpretation. Correlation of field measurements with laboratory measurements on core samples from the same area demonstrates that strong electromagnetic coupling can be accurately removed from complete spectra without removing the important rock response. Recent field and laboratory measurements indicate that most, if not all, induced polarization responses attributed to magnetite are not really due to this mineral but can be traced to a host rock alteration response. Also, characteristic host rock signatures for sulfide environments appear to vary according to locality and type of deposits making it impossible to provide a universal set of signatures for sulfide deposits.

scholarly journals Contribution of feldspar and marine organic aerosols to global ice nucleating particle concentrations

2017 ◽  
Vol 17 (5) ◽  
pp. 3637-3658 ◽  
Author(s):  
Jesús Vergara-Temprado ◽  
Benjamin J. Murray ◽  
Theodore W. Wilson ◽  
Daniel O'Sullivan ◽  
Jo Browse ◽  
...  
Keyword(s):  
Regional Distribution ◽  
Organic Aerosols ◽  
Field Measurements ◽  
Field Work ◽  
Ice Nucleation ◽  
Mixed Phase ◽  
Aerosol Composition ◽  
Desert Dust ◽  
Concentration Changes ◽  
Mixed Phase Clouds

Abstract. Ice-nucleating particles (INPs) are known to affect the amount of ice in mixed-phase clouds, thereby influencing many of their properties. The atmospheric INP concentration changes by orders of magnitude from terrestrial to marine environments, which typically contain much lower concentrations. Many modelling studies use parameterizations for heterogeneous ice nucleation and cloud ice processes that do not account for this difference because they were developed based on INP measurements made predominantly in terrestrial environments without considering the aerosol composition. Errors in the assumed INP concentration will influence the simulated amount of ice in mixed-phase clouds, leading to errors in top-of-atmosphere radiative flux and ultimately the climate sensitivity of the model. Here we develop a global model of INP concentrations relevant for mixed-phase clouds based on laboratory and field measurements of ice nucleation by K-feldspar (an ice-active component of desert dust) and marine organic aerosols (from sea spray). The simulated global distribution of INP concentrations based on these two species agrees much better with currently available ambient measurements than when INP concentrations are assumed to depend only on temperature or particle size. Underestimation of INP concentrations in some terrestrial locations may be due to the neglect of INPs from other terrestrial sources. Our model indicates that, on a monthly average basis, desert dusts dominate the contribution to the INP population over much of the world, but marine organics become increasingly important over remote oceans and they dominate over the Southern Ocean. However, day-to-day variability is important. Because desert dust aerosol tends to be sporadic, marine organic aerosols dominate the INP population on many days per month over much of the mid- and high-latitude Northern Hemisphere. This study advances our understanding of which aerosol species need to be included in order to adequately describe the global and regional distribution of INPs in models, which will guide ice nucleation researchers on where to focus future laboratory and field work.

scholarly journals Resistivity and induced polarization monitoring of biogas combined with microbial ecology at a brownfield site

2015 ◽  
Vol 3 (4) ◽  
pp. SAB43-SAB56 ◽  
Author(s):  
Carlos A. Mendonça ◽  
Rory Doherty ◽  
Nathan D. Amaral ◽  
Blathnaid McPolin ◽  
Michael J. Larkin ◽  
...  
Keyword(s):  
Water Saturation ◽  
Good Practice ◽  
Geophysical Methods ◽  
Ground Surface ◽  
Suspended Sediments ◽  
Induced Polarization ◽  
Gas Content ◽  
Archie’S Law ◽  
Monitoring Wells ◽  
Brownfield Site

The accumulation of biogenic greenhouse gases (methane, carbon dioxide) in organic sediments is an important factor in the redevelopment and risk management of many brownfield sites. Good practice with brownfield site characterization requires the identification of free-gas phases and pathways that allow its migration and release at the ground surface. Gas pockets trapped in the subsurface have contrasting properties with the surrounding porous media that favor their detection using geophysical methods. We have developed a case study in which pockets of gas were intercepted with multilevel monitoring wells, and their lateral continuity was monitored over time using resistivity. We have developed a novel interpretation procedure based on Archie’s law to evaluate changes in water and gas content with respect to a mean background medium. We have used induced polarization data to account for errors in applying Archie’s law due to the contribution of surface conductivity effects. Mosaics defined by changes in water saturation allowed the recognition of gas migration and groundwater infiltration routes and the association of gas and groundwater fluxes. The inference on flux patterns was analyzed by taking into account pressure measurements in trapped gas reservoirs and by metagenomic analysis of the microbiological content, which was retrieved from suspended sediments in groundwater sampled in multilevel monitoring wells. A conceptual model combining physical and microbiological subsurface processes suggested that biogas trapped at depth may have the ability to quickly travel to the surface.

Bed configuration and microscale processes in alluvial channels

1993 ◽  
Vol 17 (2) ◽  
pp. 123-136 ◽  
Author(s):  
André Robert
Keyword(s):  
Probabilistic Approach ◽  
Field Measurements ◽  
Bedload Transport ◽  
Transport Processes ◽  
Coarse Grained ◽  
Small Scale ◽  
Alluvial Channels ◽  
Gravel Beds ◽  
Sand And Gravel ◽  
Bed Material

Numerous recent studies on fluvial processes, both in Canada and internationally, have focused on small-scale phenomena. Investigations on the characterization of surface roughness in coarse-grained channels and its links with flow resistance and sediment transport processes have been a dominant field of research. Closely related is a second major area of investigation on turbulent flow structures in boundary layers over both sand and gravel beds and their relations with the transport of bed material. Phenomena potentially related to 'bursting' have been shown to control bedload transport processes and the concentration of sediment in suspension. Detailed investigations have also been conducted on the links between flow turbulence, bed material movement, and bed morphology at channel junctions. Finally, selective entrainment and transport of individual coarse particles have been studied from field measurements and laboratory experi ments. Emphasis has been put on bed microtopography, surface structure and texture, and on a probabilistic approach to bedload transport.

scholarly journals Issues of developing receiving equipment for the passive method of induced polarization

2021 ◽  
Vol 2094 (2) ◽  
pp. 022080
Author(s):  
P V Belolipetskii ◽  
G Y Shajdurov ◽  
V S Potylitsyn ◽  
V V Romanov
Keyword(s):  
Signal Processing ◽  
Field Work ◽  
Induced Polarization ◽  
Interference Signal ◽  
Digital Converter ◽  
Post Processing ◽  
Passive Method ◽  
Channel Interference ◽  
Input Gain ◽  
Analogue To Digital

Abstract The article deals with the design of receiving equipment for the passive method of induced polarization (IP). It is shown that the best option for recording this kind of signals is a circuit with an input analogue part and amplification of 50-100 times, as well as an input gain of at least 3 MΩ and a digital part based on a modern twenty-four-bit analogue-to-digital converter (ADC). In this case, it is preferable to use one ADC per channel without multiplexing, for better suppression of inter-channel interference. Signal processing is performed using modern microcontrollers based on the Cortex M4 core, and then the data is transmitted via Bluetooth to a laptop or tablet, where visualization and post-processing is carried out. Thus, the proposed scheme for the implementation of the receiving equipment meets all the requirements for the receiving equipment for the passive IP method, and can be introduced into the practice of field work.

scholarly journals Application of Induced Polarization and Resistivity to the Determination of the Location of Metalliferous Veins in the Taroucht and Tabesbaste Areas (Eastern Anti-Atlas, Morocco)

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Ibrahim Dakir ◽  
Ahmed Benamara ◽  
Habiba Aassoumi ◽  
Abdessalam Ouallali ◽  
Youssef Ait Bahammou
Keyword(s):  
Resistivity Measurement ◽  
Induced Polarization ◽  
Electrical Resistivity Measurement ◽  
Electrical Tomography ◽  
West African Craton ◽  
Northern Margin ◽  
Electrical Imaging ◽  
Measurement Results ◽  
Late Neoproterozoic

The study area is located in the extreme southwest of the Ougnat Mountains in the eastern Anti-Atlas, which is part of the distorted northern margin of the West African craton. It has Late Neoproterozoic to terminal, Paleozoic and Quaternary lands. In order to obtain a better recognition of the different structural contacts and to define the alignment of mineralized veins in barite and galena at the level of the study area, we used the technique of electrical tomography. The resulting response, in the form of electrical imaging, informed us in detail about the different zones of heterogeneity existing in the prospected soil. In induced polarization, the pseudosections obtained were able to locate the passages of the zones of anomalies encountered and thus confirm their alignments defined by the electrical resistivity measurement results.

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