Effects of parent material and climate on the magnetic susceptibility of Saskatchewan soils

2000 ◽  
Vol 80 (1) ◽  
pp. 135-142 ◽  
Author(s):  
E. de Jong ◽  
L. M. Kozak ◽  
H. P. W. Rostad
Keyword(s):  
Magnetic Susceptibility ◽  
Key Words ◽  
Soil Texture ◽  
Low Frequency ◽  
Parent Material ◽  
Agricultural Area ◽  
Parent Materials ◽  
Soil Zone ◽  
Magnetic Enhancement ◽  
Fe And Mn

Magnetic susceptibility (χ) of soils is easily measured; however, the link between magnetic horizonation and pedogenic factors needs to be clarified. This study compares the χ of the A and C horizons of 89 generally well-drained profiles from the agricultural area of Saskatchewan to quantify the effects of parent material and climate. Total Fe and Mn were only weakly related to χ, but χ increased as the soil texture became coarser. This trend was more noticeable in parent material than topsoil samples, and stronger for till than for fluvial, lacustrine and aeolian parent materials. The A horizon samples showed enhanced low frequency and frequency dependant χ. This increase in topsoil χ was greatest in the more humid areas. Key words: Magnetic susceptibility, parent material, climate, texture, magnetic enhancement, soil zone

X-ray fluorescence spectrometry for rapid screening of particle size in soils

2021 ◽  
Author(s):  
Maame Croffie ◽  
Paul N. Williams ◽  
Owen Fenton ◽  
Anna Fenelon ◽  
Karen Daly
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Soil Texture ◽  
Particle Size Analysis ◽  
Parent Material ◽  
Fluorescence Spectrometry ◽  
Rapid Screening ◽  
Size Analysis ◽  
X Ray

<p>Soil texture is an essential factor for effective land management in agricultural production. Knowledge of soil texture and particle size at field scale can aid with on-going soil management decisions. Standard soil physical and gravimetric methods for particle size analysis are time-consuming and X-ray fluorescence spectrometry (XRF) provides a rapid and cost-effective alternative. The objective of this study was to explore the use of XRF as a predictor for particle size. An extensive archive of Irish soils with particle size and soil texture data was used to select samples for XRF analysis. Regression and correlation analyses on XRF determined results showed that the relationship between Rb and % clay varied with soil type and was dependent on the parent material. There was a strong relationship (R > 0.62, R<sup>2</sup>>0.30, p<0.05) between Rb and clay for soils originating from bedrock such as limestones and slate. Contrastingly, no significant relationship (R<0.03, R<sup>2</sup>=0.00, p>0.05) exists between Rb and % clay for soils originating from granite and gneiss. Furthermore, there was a significant negative correlation (p<0.05) between Rb and % sand. The XRF is a useful technique for rough screening of particle size distribution in soils originating from certain parent materials. Thus, this may contribute to the rapid prediction of soil texture based on knowledge of the particle size distribution.</p><p> </p>

Reconsidering the paleoclimate implications of magnetic susceptibility records of Holocene loessic soils

2021 ◽  
Author(s):  
Diana Jordanova ◽  
Neli Jordanova
Keyword(s):  
Magnetic Susceptibility ◽  
Parent Material ◽  
Chinese Loess Plateau ◽  
Absolute Difference ◽  
Physical Parameters ◽  
Soil Profiles ◽  
Chinese Loess ◽  
Loess Area ◽  
River Terraces ◽  
Paleoclimate Proxy

<p>Mass specific magnetic susceptibility variations with depth along soil profiles developed on loess parent material is one of the most frequently used physical parameters in local, regional and global correlations of loess deposits. It is also utilized as a paleo-precipitation proxy, defined either as absolute difference between susceptibilities of the enhanced B-horizon and parent loess, or as relative enhancement using ratios of magnetic parameters. These different approaches in the application of magnetic susceptibility as paleoclimate proxy lead us to perform a comparative study on a number of Holocene soil profiles developed on loess from European loess area and the Chinese Loess Plateau (CLP). We made a compilation of data including 20 profiles from North Bulgaria, 28 profiles from Eastern and Central Europe; and 26 profiles from the CLP. Minimum magnetic susceptibilities of the last glacial loess (X<sub>min</sub>) from the compiled data base for European and Chinese profiles show climate related variability, revealing multi linear relationship with both present day MAP and MAT values for the corresponding locations. Strong deviations of X<sub>min</sub> from this dependence display sites located at low elevation river terraces, Black sea coast and possessing large content of coarse silt and sand fractions. Pedogenic magnetic susceptibility (X<sub>pedo</sub>) defined as (X<sub>max</sub> - X<sub>min</sub>) with  X<sub>max</sub> determined from the youngest part (last 1500 – 2000 years B.P.) of the Holocene magnetic susceptibility records of Chinese sections and absolute X<sub>max</sub> of the European sites show systematic dependence on modern MAP and MAT values. This dependence is uniform for all sites with steppe vegetation, while higher scatter and steeper regression trends are observed for sites under mixed (steppe – forest) and forest vegetation. The study is financially supported by project No KP-06-N34/2 funded by the Bulgarian National Science Fund.</p>

scholarly journals Eye Tracking Technology in Detecting the Switch Cost in the Intra-sentential Code-Switching Contexts

2018 ◽  
Vol 13 (05) ◽  
pp. 117
Author(s):  
Liqin Wu ◽  
Cuihua Xi
Keyword(s):  
Eye Tracking ◽  
Key Words ◽  
Word Frequency ◽  
Repeated Measures ◽  
Switch Cost ◽  
Low Frequency ◽  
Code Switching ◽  
Movement Data ◽  
Reading Efficiency ◽  
Areas Of Interest

Switch cost and cost site have been controversial issues in the code-switching studies. This research conducted an eye tracking experiment on eight bilingual subjects to measure their switch cost and cost site in comprehending the intra-sentential code-switching (Chinese and English) and the unilingual (pure Chinese) stimuli. The English words and their Chinese translations or equivalents were assumed as the key words in either a unilingual or an intra-sentential code-switching paragraph. These key words were located as areas of interest (AOI) with the same height and consisted of three word-frequency levels. After the experiment, the subjects were required to do a comprehension test to ensure their real understanding of the English words. Their performances in two different reading contexts were compared by adopting a paired sample t-test. Their eye movement data were validated by using 2 x 3 repeated measures ANOVA. It was revealed that: 1) the subjects’ scores in the intra-sentential code-switching contexts were higher than those in the unilingual ones, i.e. reading efficiency increased in the intra-sentential code-switching contexts; 2) word frequency had little effect on word recognition speed in the intra-sentential code-switching contexts, i.e., the least frequently used words did not necessarily take the subjects’ more time or vice versa; 3) even if a switch cost occurred(on rare occasions), it was not necessarily at the switching site, and low frequency words in alternating languages did impair performance even when the switch occurred at a sentence boundary.

Magnetic susceptibility of Gleysolic and Chernozemic soils in Saskatchewan

2002 ◽  
Vol 82 (2) ◽  
pp. 191-199 ◽  
Author(s):  
E. de Jong
Keyword(s):  
Magnetic Susceptibility ◽  
Key Words ◽  
Soil Samples ◽  
Sand Content ◽  
Poorly Drained Soils ◽  
Extractable Iron

In Saskatchewan, Gleysolic and Chernozemic soils often are found close to each other in hummocky terrain. Magnetic susceptibility (χ) is known to be reduced in poorly drained soils compared to well-drained soils, and this study investigated the use of χ as an accessory criterion for identifying Gleysols. Archived soil samples from an area near Saskatoon were analyzed for χ and sand content, and where necessary for organic and inorganic C and oxalate (Feo) and dithionite (Fed) extractable iron. The lowest χ values were found in Humic Luvic Gleysols and the highest in Dark Brown Chernozems; Rego and Orthic Gleysols and Rego Humic Gleysols had χ values that overlapped those of the Dark Brown Chernozems. Within the upper 50 cm of the profile, all Gleysols except the Rego Humic Gleysol had at least one horizon with %chi; less than 150 × 10-9m3kg-1. The χ of the A and B horizons was negatively correlated to their Feo/Fed ratios, and not correlated to their sand content. The χ of the deep tills was positively correlated to sand content, and not correlated to Feo/Fed ratio. It appears that χ may be as useful as the Feo/Fed ratio for assisting in classifying Gleysols. Key words: Magnetic susceptibility, Gleysols, Chernozems, Feo, Fed, CaCo3

scholarly journals FRACTIONATION OF THE HUMUS OF SOME CHERNOZEMIC SOILS OF SOUTHERN ALBERTA

1964 ◽  
Vol 44 (2) ◽  
pp. 232-236 ◽  
Author(s):  
J. F. Dormaar
Keyword(s):  
Humic Acid ◽  
Carbon Content ◽  
Black Soil ◽  
Parent Material ◽  
Glacial Till ◽  
Total Carbon ◽  
Total Carbon Content ◽  
Parent Materials ◽  
Southern Alberta ◽  
Alcohol Benzene

Two orthic profiles, widely separated geographically, of each of four parent materials—lacustrine, alluvial–lacustrine, glacial till, and Aeolian—were selected at undisturbed sites within each of the Brown, Dark Brown, and Thin Black soil zones. Material from the Ah and Bm horizons was subjected to solvent extraction, and for each sample the total organic carbon of seven different fractions was determined.The efficiency of the procedure in extracting humus carbon decreased as the total carbon content of the soil increased. Total organic matter, the first humic acid fraction, and the combined total of the three humic acid fractions showed significant differences between soil zones. The only significant separation between all four parent materials was made by the alcohol-benzene fraction. Other parent material separations were possible only following the summation of data of several fractions, such as the three humic acid fractions or the two fulvic acid fractions. A simplification of the procedure in case of soils of one Order and a modification to overcome the impeding effect of increased carbon content are requisite.

scholarly journals Low-frequency complex magnetic susceptibility of magnetic composite microspheres in colloidal dispersion

2007 ◽  
Vol 311 (1) ◽  
pp. 145-149 ◽  
Author(s):  
Ben H. Erné ◽  
Maria Claesson ◽  
Stefano Sacanna ◽  
Mark Klokkenburg ◽  
Emile Bakelaar ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Low Frequency ◽  
Colloidal Dispersion ◽  
Magnetic Composite ◽  
Composite Microspheres

scholarly journals Magnetic Response of Pr1-xLaCexCuO4 in Comparison with Hole-Doped Cuprates

2014 ◽  
Vol 215 ◽  
pp. 11-16
Author(s):  
Alexei Sherman
Keyword(s):  
Magnetic Susceptibility ◽  
Superconducting State ◽  
Projection Operator ◽  
Low Frequency ◽  
Spin Excitation ◽  
Magnetic Response ◽  
Operator Technique ◽  
Electron Band ◽  
Spin Excitations ◽  
Projection Operator Technique

The magnetic susceptibility of the optimally doped Pr1-xLaCexCuO4in the superconducting state is calculated using thet-Jmodel of Cu-O planes, the Mori projection operator technique, and the dispersion of electron bands derived from photoemission experiments. The electron band folding across the antiferromagnetic Brillouin zone border, which is inherent in the crystal, leads to a commensurate low-frequency response. The same band folding causes the appearance of a supplementary spin-excitation branch, which coexists with usual spin excitations. This coexistence can explain two maxima observed in the frequency dependence of the susceptibility. The two nested spin-excitation branches lead to a comb of closely spaced peaks in momentum cuts, which presumably are not resolved in experiment, being seen as a broad commensurate peak up to 100 meV. Reasons for differences in magnetic responses of electron- and hole-doped cuprates are discussed.

Regional geochemical mapping in areas lacking surface drainages: Cu, Fe, Mn, and Zn content of overburden and soil in south-central Saskatchewan

1979 ◽  
Vol 16 (5) ◽  
pp. 1086-1093 ◽  
Author(s):  
P. J. Doyle ◽  
W. K. Fletcher
Keyword(s):  
Statistical Significance ◽  
Parent Material ◽  
Geochemical Mapping ◽  
Parent Materials ◽  
South Central ◽  
Zn Content ◽  
Mean And Variance ◽  
Mean Differences ◽  
Iron Manganese ◽  
Range Test

An approach to regional geochemical mapping is outlined utilizing differences among mean metal concentrations for soil associated with individual parent materials. Initially the area of study is divided into parent material-based subareas for soil collection. Separate mean and variance metal values are estimated for each parent material and Duncan's Multiple Range Test is used to evaluate the statistical significance of among mean differences. Results are summarized in map form showing only compositionally distinctive parent materials or parent material groups and their associated mean and range values.This approach was tested in the Rosetown–Outlook area of south-central Saskatchewan. Results suggest that, in total, fewer than 10 samples are required per parent material to produce stable maps for copper, iron, manganese, and zinc in this 10 000 km2 area. Because of the limited number of samples needed, the method is both rapid and relatively inexpensive. It is therefore ideally suited for regional geochemical surveying, particularly in relatively arid areas where conventional lake and stream sediment-based procedures are not applicable.

Swimming Stamina Differences Between Genotypically Distinct Forms of Rainbow (Salmo gairdneri) and Steelhead Trout

1977 ◽  
Vol 34 (7) ◽  
pp. 996-1003 ◽  
Author(s):  
H. Tsuyuki ◽  
S. N. Williscroft
Keyword(s):  
Rainbow Trout ◽  
Lactate Dehydrogenase ◽  
Key Words ◽  
Low Frequency ◽  
Water Velocity ◽  
Salmo Gairdneri ◽  
Steelhead Trout ◽  
Very Low Frequency ◽  
Time Required

Rainbow trout (Salmo gairdneri) homozygous for liver lactate dehydrogenase alleles ldhHαA and ldhHαB were artificially propagated and their swimming stamina compared. The time required to fatigue 50% of the HαAHαA phenotypes in fixed water velocity tests was 2.3 times greater on the average than that of HαAHαB phenotypes.Likewise, LDH phenotypes HαAHαA, HαAHαB, and HαAHαB of steelhead trout from the Thompson River were artifically propagated and their swimming stamina compared. In contrast to the rainbow trout, significant differences in stamina among the three phenotypes of steelhead were not evident in the stocks from this river nor between phenotypes HαAHαB and HαBHαB from another stream, the Vedder River, which has a very low frequency of the ldhHαA allele. The stamina of young steelhead from the Thompson River was, however, 3.8 times greater than that of those from the Vedder River. Key words: stamina, LDH, rainbow trout, steelhead, phenotype, swimming, fatigue

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