Mineralogical and weathering study of a red-brown earth formed on granodiorite

Soil Research ◽  
1966 ◽  
Vol 4 (2) ◽  
pp. 181 ◽  
Author(s):  
P Green

The development of a red-brown earth has been studied by means of mineral and fabric analyses. Data from particle-size analysis and zircon distribution indicate relative uniformity of the parent material throughout the profile, with a possible minor disconformity near the bottom of the B horizon. Calculations of gains and losses of major minerals during soil formation, based on the zircon content of each soil horizon and of the rock, show a break in the progressive increase in weathering towards the surface, suggesting that the soil is in fact a two-storied profile; micromorphological evidence supports this postulate. The constancy of the qualitative mineral assemblage, however, shows that both sola were formed entirely from the underlying weathered granodiorite. The top four horizons are interpreted as being a separate soil, probably developed from a surface movement layer composed of some material from the upper horizons of the older profile with accessions from weathering granodiorite boulders. Both soils are considered to have been formed dominantly by in situ weathering of primary minerals and removal of the weathering products by leaching; clay illuviation does not appear to have been more than a very minor soil-forming process.

1983 ◽  
Vol 63 (2) ◽  
pp. 259-269 ◽  
Author(s):  
K. GHEBRE-EGZIABHIER ◽  
R. J. ST. ARNAUD

The nature and distribution of carbonate minerals in the upper Qu’Appelle basin in south-central Saskatchewan were investigated. The equivalent carbonate content and calcite:dolomite ratios of the deposits reflect the mechanisms of glacial deposition and some differences in the sources of the original parent material. The particle size analysis shows that the Qu’Appelle Lake sediments are more clayey than the surrounding soils and till deposits. Mg-bearing calcites occur only in the fine-sized fraction of the carbonate accumulation horizons. However, most of the upper Qu’Appelle Lake sediments contain appreciable amounts of sand-sized Mg-bearing calcites. The marked increase in carbonate content of the sediments relative to the adjacent soils and deposits is partially due to direct precipitation of calcite from the supersaturated lake waters. In this respect, a good correlation exists between the lake water ionic activity products for CaCO3 and the relative equivalent carbonatic mineral contents of the sediments. Key words: Mg-bearing calcite, dolomite, IAP, erosion


2021 ◽  
Author(s):  
Maame Croffie ◽  
Paul N. Williams ◽  
Owen Fenton ◽  
Anna Fenelon ◽  
Karen Daly

<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>


2021 ◽  
Author(s):  
Anastasiia Kimeklis ◽  
Grigory Gladkov ◽  
Aleksei Zverev ◽  
Arina Kichko ◽  
Evgeny Andronov ◽  
...  

<p>Pedogenesis depends on multiple factors, such as climate, vegetation, topography, parent material. Some of these factors are zonal, meaning they are determined by climate zone. But some factors are intrazonal, meaning that it has the same impact on soil formation in different climate zones. One example is parent material. The other peculiar feature of a parent material is that it determines the rates of pedogenesis. In this regard, Rendzic Leptosols – are intrazonal slowly developing soils formed on a limestone bedrock. In this study we approached the dynamics of microbiome formation in a chronosequence of these soils collected in Crimean Peninsula using analysis of 16S rRNA gene libraries and quantitative PCR. The chronosequence included benchmark soil, 700 year-old soil from the ancient city of Eski-Kermen, 70 year-old soil from WWII trenches and 50 year-old soil from the open quarry screenings. Our research demonstrated that soil type on a limestone rock is the driving force behind microbiome shaping, without any apparent influence of its age. Dominant phyla for all soil sites were Actinobacteria, Proteobacteria, Acidobacteria, Bacteroidetes, Thaumarchaeota, Planctomycetes, Verrucomicrobia and Firmicutes. Alpha diversity was similar across sites and tended to be higher in topsoil. Beta diversity showed that microbiomes diverged according to the soil site and the soil horizon. CCA analysis, in combination with PERMANOVA, linked differences in microbiomes to the nutrients associated with the soil horizon, and our analysis showed that the reactive component of the soil microbiome shifted simultaneously in both soil horizons between different soil sites.</p><p>The work was supported by the grant of the Russian Scientific Foundation, project 17-16-01030.</p>


Soil Research ◽  
1963 ◽  
Vol 1 (1) ◽  
pp. 74 ◽  
Author(s):  
KG Tiller

The mineralogy and chemistry of weathering and soil formation have been studied at 17 widely separated sites with contrasting climatic conditions on comparatively uniform dolerite in Tasmania. The clay and fine sand mineralogy of the soils has been related to their degree of weathering. These studies have shown large chemical and mineralogical changes accompanying the initial stages of weathering in some krasnozem soils. The reorganization of cobalt, zirconium, nickel, copper, molybdenum, manganese, and zinc during genesis of four soil groups has been considered in terms of the factors involved. Some of these results indicate that the clay horizon of the podzolic soils has probably been formed by weathering in situ. Seasonal waterlogging in certain horizons has strongly mfluenced the chemistry and mineralogy of weathering in many of these soils. This study has shown that the composition of the parent material has only influenced the geochemistry of trace elements in less weathered soils and that pedogenic factors assumed greater significance as the soils became more strongly weathered. Geomorphic processes had a marked influence on the geochemistry of some soils by the truncation of mature soil profiles.


2019 ◽  
Vol 20 (1) ◽  
pp. 435-451 ◽  
Author(s):  
Aleksandra Loba ◽  
Marcin Sykuła ◽  
Jakub Kierczak ◽  
Beata Łabaz ◽  
Adam Bogacz ◽  
...  

Author(s):  
Sandra Cristina Deodoro ◽  
William Zanete Bertolini ◽  
Plinio da Costa Temba

Quaternary formations (detrital and weathered materials) are an important natural resource for different areas of scientific investigation, from understanding their relation to erosive processes and morphodynamic processes that create landforms or to understanding the history of the first human settlements (geoarcheology). Quaternary coverings can be formed in situ or be transported by external geologic agents. Regarding soils, Quaternary formations are related to landscape topography and are transformed according to the characteristics of this topography. Hence, classifying and mapping these soils is not always easy. The present article aims to map the Quaternary formations along a stretch of the Uruguay River basin  known as Volta Grande (SC/RS-Brazil), by using  topographic attributes derived from the SRTM GL1-Up Sampled digital elevation model, soil particle-size analysis, and a generated Multiresolution Index of Valley Bottom Flatness (MRVBF) index . The results of the analysis show that: (i) colluvium is the predominant Quaternary formation in the study area; (ii) there is a predominance of clay, corroborating previous studies of the region; (iii) the spatial distribution of the study area’s  Quaternary formations reflect local slope dynamics based on morphology and topographic position; and, (iv) the existence of colluvium-alluvium on the Uruguay River’s banks indicates that slope attributes contributed to the pedogeomorphological dynamics of the study area and not only fluvial dynamics. Based on the results, the methodology applied in this study might be useful for pedogeomorphological studies, notably in the analysis and mapping of Quaternary formations, despite some of its limitations.


Soil Research ◽  
1981 ◽  
Vol 19 (1) ◽  
pp. 1
Author(s):  
AJ Koppi

A common toposequence on Bunya Phyllite in south-east Queensland was studied in detail at a representative site. Four sample profiles on the slope are described, and some physical and chemical properties are given. The clay minerals, derived from the weathering of the quartz-sericite-chlorite phyllite, comprise dioctahedral mica, dioctahedral vermiculite, an interstratification of these minerals, and kaolin. Properties are related to the slope; and the clay-rich horizon of the middle and lower slopes is considered to be formed mostly by in situ weathering. The classification of the genetic unit given by the slope and parent material is discussed.


2002 ◽  
Vol 759 ◽  
Author(s):  
William J. Walker

ABSTRACTDie compaction of granulated powder is a common forming process used in the ceramics industry. Glass spheres were used as a model system to investigate granule failure during die compaction. Since glass spheres are brittle, failure results in fragmentation. Particle size analysis of the resulting fragments demonstrates the statistical nature of granule failure during compaction, with some granules failing at very low applied pressures while a large fraction persist at even the highest applied loads. The results are discussed in terms of the Andreasen, Furnas and Dinger-Funk particle packing models for continuous size distributions.


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