Basic Parent Material Research Articles

Specific Surface Area and Multifractal Parameters of Associated Nitrogen Adsorption and Desorption Isotherms in Soils from Santa Catarina, Brazil

Nitrogen adsorption isotherms (NAI) and Nitrogen desorption isotherms (NDI) are commonly used to evaluate specific surface area (SSA) of soils and other materials. Scaling analysis of N2 isotherms yield complementary information about the complexity of the soil surface. We evaluated the specific surface area (SSA) and examined the scaling properties of NAIs and associated NDIs from clayey soils, rich in organic matter sampled in Santa Catarina State, Brazil. Sixty six soil horizons were sampled in 13 profiles. Ten of these profiles were developed over volcanic rocks with a wide range of mineralogical composition. Clay content and cation exchange capacity (CEC) showed a weak positive correlation to SSA, which was attributed to variable clay mineralogy. Organic carbon content showed a weak negative correlation to SSA. Both NAIs and NDIs exhibited multifractal behavior, but its scaling properties were different so that adsorption isotherms showed higher scaling heterogeneity and were less evenly distributed measures than desorption isotherm. Also, parameterization by the Hurst exponent indicates NAIs were less persistent than NDIs. Differences in multifractality between NAIs and NDIs were attributed to contrasting physical processes during adsorption and desorption. Both, SSA and various multifractal parameters estimated from NAIs and NDIs differentiated between soils developed over either acid or basic parent material. Linear regression and principal component analysis (PCA) showed increasing carbon content decreased scaling heterogeneity and increased persistence of both, NAIs and NDIs. On the other hand, increasing clay content showed a trend to increase scaling heterogeneity and to decrease persistence during the adsorption and desorption phases.

Tropical Soils and Landmine Detection—An Approach for a Classification System

Electromagnetic induction is the most common technique used in landmine detection. In soils exhibiting high magnetic susceptibility, metal detectors based on this method may become useless for landmine detection. Currently, no soil classification system exists that allows a prediction of negative effects on metal detectors. A total of 511 tropical soil samples from 15 different countries were investigated with regard to their susceptibility and some basic chemical parameters. Samples were separated into six classes based on their chemistry and their parent material. Soils derived from ultrabasic to basic parent material, on average, exhibited the highest susceptibilities because both rock types often contain a large amount of weathering‐resistant magnetite. Independent of the origin, the variance of the susceptibilities is large. Even in soils derived from rocks initially low in magnetite, high susceptibilities may develop with pedogenesis. This may be due to either the enrichment of residual magnetite or the formation of maghemite. In addition to a soil's parent material, its degree of weathering should also be considered in a proper classification scheme. We used a coefficient based on soil chemistry that correlates with the degree of weathering. Based on this coefficient and the soil parent material, we determined the median and the 90th percentile of the corresponding distribution of soil susceptibilities for each combination of the classification factors. The resulting classification scheme has the form of a matrix and may serve as a first approximation of expected susceptibilities when only parent material and degree of weathering are known.

Weathering and atmospheric deposition signatures of base cations in upland soils of NE Scotland: their application to critical load assessment

Although the importance of atmospheric base cation deposition to soils is increasingly acknowledged, field data demonstrating the signatures of atmospheric and weathering-derived cations are seldom presented. This paper explores how combined atmospheric and internal base cation inputs are reflected in exchangeable and soil solution base cation compositions of upland soils, ranging from acidic to basic parent materials. Although total atmospheric base cation deposition exceeded weathering inputs for most soils, relative proportions of exchangeable base cations were controlled by parent materials. Calcium and magnesium concentrations were most closely related to geology, but were likely affected by the affinity of humic material for divalent cations, which resulted in elevated concentrations in surface horizons. In contrast, soil solution compositions deviated little from those of precipitation, showing minimal geochemical influence. A soil-based weathering rate index utilizing the dominance of the base cation Na was explored with the goal of enhancing spatial resolution in critical load assessment. However, the calibration of the relative proportions of exchange site Na against weathering rates, determined by three conventional critical load calculation methods, was inconclusive. Although power relationships were suggested, these were poor and largely insignificant, with a considerable range of %Na values at low weathering rates. It was not resolved whether the data available was insufficient to obtain accurate weathering rates, or that the base cation chemistry was affected by factors other than weathering alone.

Biological influences on the morphology and micromorphology of selected Podzols (Spodosols) and Cambisols (Inceptisols) from the eastern United States and north-east Scotland

Biological activities greatly influence the formation of many soils, especially forest soils under cool humid climates. The objective of this study was to investigate the effects of vegetation and soil biota on the formation of selected soils. Field morphology, micromorphology, and carbon and organic matter analysis were determined on six Podzols (Spodosols) and two Cambisols (Inceptisols) from the eastern United States and north-east Scotland. Humification of plant material by soil fauna and fungi occurs in all organic horizons. Thick organic coatings are observed on soil peds and rock fragments from the E1 to the Bs horizon in a Haplic Podzol from Clingmans Dome Mt., TN. Thin sections reveal large accumulations of root material in different stages of decomposition in the spodic horizons of a Haplic Podzol from Whiteface Mt., NY. Organic carbon ranges from 5.4 to 8.5% in the spodic B horizons of the Whiteface Mt. Podzol. Earthworms and enchytraeids have a great effect on the structure of the surface and subsurface horizons in the Dystric Cambisols from Huntly and Clashindarroch Forests, Scotland and a Cambic Podzol from the Corrie Burn Basin, Scotland. Podzols from Speymouth Forest, Scotland (Gleyic Podzol), Clingmans Dome Mt., and Whiteface Mt. have thick organic horizons. The Podzols from the Flatwoods in Georgia, the Pine Barrens in New Jersey, the Corrie Burn Basin, and the Cambisol from Huntly Forest have only A horizons at the surface. The Clashindarroch Forest soil has a very thin organic horizon. Warm and humid climates and sandy parent material are responsible for thick E horizons and lack of thick organic horizons in the Flatwoods (Carbic Podzol) and Pine Barrens (Ferric Podzol) soils. Earthworms and enchytraeids thrive in the Corrie Burn Basin and Huntly Forest soils due to the vegetation and the highly weathered basic parent material. The site at Clashindarroch once carried oak, and then birch forest, both of which produce a mild litter and also encourage earthworm and enchytraeids. This fauna is responsible for much mixing of the topsoil. The present conifer vegetation will eventually produce a deep litter and cause podzolization.

Soil Water Effects on Growth and Nutrition in Upland Pastures

Normally the oceanic climate of Scotland maintains soils at low levels of soil water deficit. Field data for such a year are presented and compared with those for an unusually dry year, with the objective of assessing to what degree dry spells might limit herbage production in upland pastures. One meter square plots were sampled on selected dates on reseeded pastures growing on each of 3 cambisols, each derived from different parent materials. The swards were unfertilized and maintained at nominal heights of 2, 4, 7, and 10 cm by cutting every 2 or 3 weeks to manipulate growth and demand for P and N. Overall yield was 25 to 50% lower in the dry year compared with an average year. Peaks and troughs in growth rates, measured as yield at each cutting, and in P and N content, corresponded to changes in soil water deficit in the top meter of soil. The linear correlation coefficient between soil water deficit and growth rate was -0.894 (P = 0.001). Although there was some variation in volumetric water content between soils, soil water deficits were similar in all the cambisols. Yields and nutrient contents were generally similar for herbage harvested from the 2 soils having basic parent material (one a eutric and one a dystric cambisol) and lower on the dystric cambisol derived from schists. The effects of water content largely over-rode cutting treatments, demonstrating that dry spells occasionally occurring in the oceanic climate of Scotland can significantly affect grassland production.

Relationships between ultraviolet absorbance and total organic carbon in two upland catchments

Regression equations relating u.v. absorbance to total organic carbon (TOC) in river water are compared for streams draining two upland catchments in north-east Scotland which have similar climate, topography and land use but contrasting acidic and basic parent materials. A comparison is also made of regression equations for individual tributaries contributing to the main streams in each catchment. Reasons for observed differences are suggested. Changes in u.v. absorbance vs TOC relationships through storm events are discussed, and the problems associated with using TOC/absorbance relationships to monitor changes in TOC with time through storms are briefly considered.

Classification of soils developed on basic parent materials in the Canadian and French systems of soil classification : DeKimpe, C R; Dejou, J Can J Soil Sci V66, N1, Feb 1986, P177–181

Classification of soils developed on basic parent materials in the Canadian and French systems of soil classification : DeKimpe, C R; Dejou, J Can J Soil Sci V66, N1, Feb 1986, P177–181

Effects of acidic and basic parent materials on formation of some soils in Quebec (Canada)

Five profiles developed on basic or acidic parent materials were sampled in southern Quebec, Canada. Physical, chemical and mineralogical properties were determined. Among the three profiles developed on basic parent materials, one formed in disaggregated metabasalt whereas the two others developed in preglacial saprolites derived from the metabasalt, as indicated by till cover in a nearby area. In the lower part of the latter profiles, the saprolites had a loamy texture and the mineralogical plus chemical data indicated very slight changes with respect to the metabasalt. In these profiles, CBD-extractable Fe content was > 1% in most horizons, and the pyrophosphate-extractable Fe was generally higher in the Ah than in the B horizons. In the profiles developed on acidic till, CBD-extractable Fe was > 1% only in the B horizons, which also contained the maximum of pyrophosphate-extractable Fe. In the latter profiles, free Fe and Al sesquioxides were associated with the clay fractions whereas in the former profiles, one third of the Fe came from the sand and silt fractions. Chlorite was the dominant phyllosilicate in the basic material and it was transformed into interstratified minerals and smectite. Several hypotheses about smectite formation and distribution were discussed. In the profiles developed on acidic till, illite and chlorite were the major phyllosilicates and, through weathering, transformed into interstratified minerals, vermiculite and smectite. Major differences in the properties of the profiles developed on the two parent materials were not reflected by current soil classification.

Geochemistry, petrology and RbSr dating of trondhjemite and granophyre associated with Jabal Tays Ophiolite, Idsas area, Saudi Arabia

Abstract Jabal Tays trondhjemite and granophyre are leucocratic acidic rocks that intrude the melange zone of an ophiolitic complex. They consist of two small stocks 200 m in diameter and some dikes and vein-like bodies. Petrographically, they are medium—fine grained hypidiomorphic granular rocks consisting mainly of plagioclase (An10–60) and quartz which commonly shows myrmekitic texture. The mafic minerals are primarily biotite and muscovite, with occasional sericite, chlorite and epidote pseudomorphs after hornblende. The bulk chemical composition and trace elements are similar to trondhjemites from other ophiolite complexes. They also show calc-alkaline affinity. The K/Rb, Rb/Sr, and initial 87Sr/86Sr ( 0.7030 ± 0001 ) ratios, as well as the depletion of the (LIL) elements suggest an origin by partial melting of basic parent material in an island-arc tectonic setting over a subduction zone. The granophyres probably evolved from the trondhjemites either by crystal fractionation or crustal contamination. The whole-rock RbSr isochron age of 620 ± 40 Ma places an upper limit on the geologic and tectonic evolution of the Jabal Tays ophiolitic complex.

EFFECT OF SOIL PARENT MATERIAL, ELEVATION, ASPECT AND FERTILIZER TREATMENT ON UPLAND GRASS YIELDS

ABSTRACTGrass production was measured at 24 sites in the Strathdon area of West Aberdeenshire. The mean total yields of DM from two cuts taken from unfertilized plots in 1967 and from three cuts taken in 1968 were 3014 and 3864 kgJha, respectively. Yields from soils formed on basic parent material were 30–40% more than yields from soils formed on more acidic material; and well‐managed swards yielded over 40% more than poorly‐managed ones. Aspect did not affect yields significantly, nor did elevation within the range 260–440 m.NItrochalk applied at the rate of 75 kg N/ha in 1968 increased the DM yield by an average of 35% but the efifect of 75 kg P2O5/ha, applied as triple superphosphate, was not significant at the 10% level. The benefits from N declined, wbereas those from P tended to increase, with elevation. There was no significant NP interaction overall, but tbe response from this treatment was better than from N alone on sites with acidic parent material.In 1968, 46% of the total yield was obtained by the end of June and only 10% after the end of August. Whereas yield declined with elevation in May–June, it increased during July–August

Factors Affecting the Frequency Distribution of Clay Minerals in Soils

An extensive survey of the clay minerals and the other mineral colloids of many soils led to the conclusions that the chemical environment that exists in a soil during its development determines the kind of clay minerals that are being formed and that the frequency distribution of the clay minerals and the other mineral colloids, exclusive of those inherited from the parent material, are determined by the chemical environment occurring during soil formation. Furthermore, the chemical environment also determines the nature and extent of the alteration that biotite and muscovite undergo during breakdown to colloidal dimensions.Because the chemical environment of a soil is determined by the factors of soil formation, a good correlation exists between these factors and the frequency distribution of the clay minerals.Any of the factors of soil formation that function to maintain a neutral or an alkaline environment and to accumulate CaCO3 also induce the formation and accumulation of montmorillonite—whether this formation is through synthesis or through the alteration of micas and vermiculites. Thus, highly basic parent materials, such as serpentines and periodotites, that tend to maintain a neutral to basic environment regardless of degree of leaching, induce montmorillonite formation. Also under low rainfall conditions montmorillonite always accumulates regardless of the nature of the parent materials. Furthermore, conditions that impose on the soil a base accumulating environment, such as poor drainage, high water table, or its position in the profile as deep horizons, also induce montmorillonite formation. If potassium is high in such an environment, the mica minerals are either synthesized or accumulated.Any of the factors, however, that function to maintain a highly base-depleting environment, such as high rainfall, good drainage and a high permeability, or the position of a soil in the profile as surface horizons, are conducive to kaolinite and halloysite formation. Acidic parent materials with high permeability, such as pumice and volcanic ash, or very dense basic rocks, such as basalts that have an extremely low water holding capacity, are particularly responsive to kaolinite and halloysite formation even at moderate precipitation.Any of the factors that function to maintain an intermediate environment, i.e. between a highly accumulating and a highly depleting one, induce the formation of vermiculite either by synthesis or by the alteration of the micas. Soils found presently in such environments have the broadest frequency distribution of clay minerals. This is believed to reflect an environment that has responded readily to change in the course of soil development, particularly with respect to changes in rainfall and temperature.