Red Soil in Northern Sri Lanka is a Natural Magnetic Ceramic

2009

2005

In this paper magnetic property of the Delhi topsoil has been used to characterize the potentially polluted areas in terms of magnetic minerals and grain (Magnetic Domain) concentration as a factor of toxic metals and other mutagenic pollutant concentration. The Saturation magnetisation (Ms) and Saturation remanence (Mrs) has been taken as proxy for ferrimagnetic mineral concentration. However, delineation of anthropogenic magnetic fraction from lithogenic (geogenic) magnetic fraction has been done by the paramagnetic/diamagnetic contribution of soil with the fact that the fresh soil contains higher paramagnetic and diamagnetic minerals than polluted. Predominantly, the topsoils of Delhi are dominated with ferrimagnetic minerals (Magnetite and Maghemite phase). Significantly the industrial areas contain highest concentration of the ferrimagnetic minerals with negligible paramagnetic/diamagnetic fraction which leads to anthropogenic contribution. Heavy traffic and densely populated areas of the Delhi exhibit moderate to low soil pollution while green areas show lowest with higher paramagnetic/diamagnetic contribution. The soils in Delhi are dominated with Pseudo-Single Domain (PSD) magnetic grain, though the industrial areas in Delhi show coarser Multidomain (MD) grains in comparison to Stable Single Domain (SSD) in forest areas. Our study reveals that the fine grain particle does not show significant link with higher concentration of ferrimagnetic minerals at least in soils. The presence of the lithogenic magnetite crystal in the forest soil and anthropogenically produced spherules in industrial areas and higher concentration of the heavy metal in Delhi soil strengthen our findings.

4th Annual International Conference on Geological and Earth Sciences (GEOS 2015), 2015

Electrical and magnetic properties have been used in soil characterization for various types of soils except for soil originated from sag pond sediment. Formed near fault line, sag pond provides a unique environment for sedimentation. In this study, electrical conductivity and magnetic susceptibility of soil samples obtained by coring process were measured to find out how these two properties were related. A 364 cm core was obtained in a sag pond located next to Lembang Fault in West Java, Indonesia. The core covers two different layers that are differ not only on their coloration and texture but also showed variations in their electrical conductivity and magnetic susceptibility. In the first layer, termed silty loam (above 165 cm), electrical conductivity correlates positively with magnetic susceptibility whereas in the second layer, termed silty-clay (below 165 cm) the correlation is negative. These differences are probably due content of magnetic minerals that is high in silt but low in clay. The results of this study infer that correlation between electrical conductivity and magnetic susceptibility could then be used as a tool to delineate soil layers.

Proc. SPIE, 2005

In the present research work, studies on correlation factors of electrical conductivity of soils in India with their physical properties like texture, bulk density and porosity were reported. We collected 29 soil samples from different locations of Karnatakta, Tamilnadu, Uttarakhand and Madhya Pradesh states of India. Soil samples were analyzed for physical parameters. Statistical correlations were obtained between electrical conductivity and different parameters of soil samples. Our results show significant correlations between electrical conductivity and physical parameters of soils. Besides agricultural applications, such studies may find importance in better understanding of soil physics and also for analyzing the satellite data in remote sensing.

Advances in Research

EM-38 electromagnetic induction sensor is a most useful instrument to determine the soil salinity. Significant positive correlation found between inductive electromagnetic meter (IEM) readings and saturated paste extract electrical conductivity (EC) revealed that this technique could be used for determination of soil salinity. However, calibration of the instrument is necessary for interpretation of instrument readings in terms of meaningful parameters of soil salinity. The calibration equations developed elsewhere may not predict electrical conductivity of UAS, Raichur soil accurately. So, in this study, calibration of EM-38 was carried out to find the soil salinity of experimental site soil. A

Chinese Science Bulletin, 2000

An investigation of magnetic properties using magnetic susceptibility ( χ ) and frequencydependent susceptibility ( fd χ ) was conducted on representative modern pollutants, which include smelted slag dust, automobile exhaust dust and coal ash. Their magnetic susceptibility values are more than 500×10 -8 m 3 /kg, and frequency-dependent susceptibility values less than 3%, indicating that ample ferrimagnetic and scanty superparamagnetic grains occurred in the studied pollutants. Similar to the artificially synthetic polluted soils, the industrially-polluted soils display a negative relationship between magnetic susceptibility and frequency-dependent susceptibility. However, the unpolluted soils, e.g. the Quaternary loess in the Chinese Loess Plateau, show a positive relationship between them. In this note, we propose a convenient and effective approach for identifying the polluted soils.

Electric Field [Working Title], 2019

Precision farming involves the collection of detailed information about the characteristics of agricultural operations. Electro-conductivity (EC) of soil is one of the tests easier and less costly for agriculture, which can be performed today. Electro-conductivity (EC) is the ability of a material to transmit (conduct) an electrical current and is usually expressed in miliSiemens / meter (MS / m). Electro-conductivity (EC) of soil is a measurand that characterizes many soil properties which affect the productivity of crops. These include the water content, soil texture, soil organic matter (OM), depth to clay layer, the capacity of cation exchange (CEC), salinity, calcium, magnesium. Measurements of electro-conductivity (EC) of soil can add value to agricultural operations if they can be used to help explain variations in agricultural production. Article shows electro-conductivity maps models of the prepared soil in different locations in Romania and electro-conductivity correlation...

Geoderma, 2000

Ten selected Brazilian soils representative of Oxisols, Ultisols, Alfisols and Inceptisols and derived from gneiss, basalt, sandstone, diabase and itabirite were sampled and examined to provide insight into the behavior of their magnetic minerals. The objective was to measure the magnetization of the sand, silt and clay fractions and to submit the clay fraction to variable magnetic fields to obtain the magnetization curves and to study their magnetic behavior as related to their parent material lithology. The separation procedure using a magnetic separator was done in two different ways: dry separation for the sand and wet separation for the silt and clay fractions. X-ray diffraction patterns of magnetic and nonmagnetic fractions were obtained and the segrega-Ž . tion of ferrimagnetic minerals were shown. The magnetization s of the total and the magnetic s and nonmagnetic soil fractions was evaluated using a special analytical balance. The s values s obtained varied from 0.03 to 17.72 J T y1 kg y1 for sand; 0.05 to 8.91 J T y1 kg y1 for silt and ) Corresponding author. M.P.F. Fontes . 0016-7061r00r$ -see front matter q 2000 Elsevier Science B.V. All rights reserved. Ž . PII: S 0 016-7061 00 00005-7 ( ) M.P.F. Fontes et al.r Geoderma 96 2000 81-99 82 0.05 to 2.54 J T y1 kg y1 for the clay fractions. The results from the magnetically concentrated fractions varied in the same fashion but reached higher values. Magnetization curves showed Ž . y1 y1