Morphological, physical, and clay mineralogy of calcareous and gypsiferous soils in North of Lorestan, Iran

2019 ◽  
Vol 99 (4) ◽  
pp. 485-494
Author(s):  
Kolsum Rahman Salari ◽  
Mohammad Amir Delavar ◽  
Mehrdad Esfandiari ◽  
Ebrahim Pazira
Keyword(s):  
Electron Microscopy ◽  
Calcareous Soils ◽  
Clay Mineralogy ◽  
Limited Information ◽  
Soil Taxonomy ◽  
Kaolinite Clay ◽  
Piedmont Plain ◽  
Transmission Electron ◽  
Parent Rocks ◽  
Pedogenic Processes

There is limited information about the genesis, classification, and properties of calcareous and gypsiferous soils of western Iran. This study investigated the morphological, physical, and mineralogical characteristics of soils on different physiographic units, including plateau, colluvial fans, and piedmont plain in the Aleshtar region. The results indicated that the parent materials (calcareous and gypsiferous) as well as topographic conditions had the most influence on the soil profile development, pedogenic processes, and clay mineralogy. Illite, chlorite, smectite, palygorskite, and kaolinite clay minerals were identified using X-ray powder diffraction, transmission electron microscopy, and scanning electron microscopy. Illite, chlorite, and kaolinite have genetically been inherited from parent rocks. Neoformation of smectite and palygorskite other than genetic inheritance was formed as a result of calcite and gypsum precipitation and poor drainage. Calcareous soils with the petrocalcic horizon and gypsiferous soils contained more pedogenic palygorskite. In conclusion, we suggest adding a new great group of Gypsixerepts to the soil taxonomy to reflect the presence of pedogenic gypsum in Inceptisols.

Kaolin in the net-like horizon of laterite in Hubei, south China

Clay Minerals ◽  
2009 ◽  
Vol 44 (1) ◽  
pp. 51-66 ◽  
Author(s):  
Hanlie Hong ◽  
Zhaohui Li ◽  
Muzhuang Yang ◽  
Ping Xiao ◽  
Huijuan Xue
Keyword(s):  
Electron Microscopy ◽  
South China ◽  
Energy Dispersive Spectrometer ◽  
Clay Mineralogy ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Chemical Index ◽  
Mineral Components ◽  
Chemical Index Of Alteration ◽  
Matrix Components

AbstractThe clay mineralogy and chemical composition of the white veins, red matrix and both Fe- and Mn-bearing nodules occurring in a laterite profile in Hubei, south China were investigated using X-ray diffraction, scanning electron microscopy equipped with an energy-dispersive spectrometer, and high-resolution transmission electron microscopy. The results show that the mineral components of the red matrix are mainly quartz, kaolinite, halloysite, goethite and minor illite, whereas the white net-like veins contain mostly quartz, kaolinite, halloysite, and illite. In the net-like horizon, the chemical index of alteration (CIA, the ratio of Al2O3/(Al2O3+CaO+K2O+Na2O)) and the TiO2/Al2O3 ratio are 89.8% and 0.021 for the white vein and 90.7% and 0.025 for the red matrix, respectively. Both white-vein and red-matrix components have similar TiO2/Al2O3 ratios, and are similar to the ratio 0.027 of the unaltered bedrock. The similarity in TiO2/Al2O3 values indicates that all three portions of the laterite soil share the same origin. Also, although the white-vein and red-matrix components differ in Fe2O3 abundance, the similar CIA values do imply similar degrees of alteration. The Fe-bearing and Mn-bearing nodules were produced by the local accumulation of Fe2O3 and MnO, respectively. Halloysite in the weathering profile occurs in two different morphologies, tubular and platy crystals. Tubular halloysite occurs both in the red matrix and the Fe-bearing nodule whereas platy halloysite occurs only in the white vein and Mn-bearing nodule assemblages. Crystallization of small tubular halloysite from Si and Al concretions in the red matrix is observed, indicating that the morphology of these crystals in the weathering environment is mainly controlled by Fe3+ cations, whereas platy halloysite may be derived from the hydration of kaolinite.

Clay mineralogy of soils formed in tuffaceous greywacke, Southland, New Zealand, in relation to genesis, soil properties and classification

Soil Research ◽  
1991 ◽  
Vol 29 (4) ◽  
pp. 493 ◽  
Author(s):  
GJ Churchman ◽  
PD Mcintosh ◽  
CM Burke ◽  
JS Whitton
Keyword(s):  
New Zealand ◽  
Trace Element ◽  
Clay Mineralogy ◽  
Parent Material ◽  
Soil Drainage ◽  
Geological Time ◽  
Soil Taxonomy ◽  
Simple Chemical ◽  
Parent Rocks ◽  
Upland Soils

The clay mineralogy of 12 soils (Dystrochrepts, a Eutrochrept, a Cryochrept and a Placaquept) formed in tuffaceous greywacke parent rocks is presented and discussed. In a New Zealand context, the soils are unusual because of their base-rich parent material which has been partly pre-weathered to smectite and kaolin minerals in geological time. Superimposed on this assemblage are the affects of present climate and soil drainage, which have altered smectite and vermiculite to dioctahedral (aluminous) chlorite. Conventional laboratory treatments cause dioctahedral chlorite to revert fully to smectite or vermiculite, or alternatively partially to interlayered hydrous mica. The labile nature of the interlayer Al is evident in high KCI-Al values. Allophane and gibbsite occur in acid upland soils that are also trace-element deficient. More intense leaching of upland soils with respect to lowland soils accounts for the upland soils' clay mineralogy and trace element deficiencies. The soils fall into three mineralogy classes of Soil Taxonomy and six classes of the proposed Whitton and Childs revision. The classes are not readily usable in the field, and subgroup or family distinctions based on simple chemical tests are suggested.

Impacts of clay mineralogy and physiographic units on the distribution of potassium forms in calcareous soils in Iran

Clay Minerals ◽  
2009 ◽  
Vol 44 (3) ◽  
pp. 327-337 ◽  
Author(s):  
S. Rezapour ◽  
A. A. Jafarzadeh ◽  
A. Samadi ◽  
S. Oustan
Keyword(s):  
Calcareous Soils ◽  
Clay Mineralogy ◽  
Soil Formation ◽  
Alluvial Plain ◽  
X Ray Diffraction ◽  
Piedmont Plain ◽  
Physiochemical Properties ◽  
Exchangeable K ◽  
North West ◽  
Diffraction Patterns

AbstractThe potassium pools of five major physiographic units of the Urmia region situated in western Azerbaijan province, north-west Iran, were studied to determine the distribution of K forms as functions of clay mineralogy and physiographic units. Soil samples from horizons of ten pedons were selected and analysed for physiochemical properties, clay mineralogy and forms of K. X-ray diffraction patterns revealed that the soils were similar in clay-mineral compositions, consisting of illite, smectite, chlorite, and kaolinite, for the different physiographic units, but vary in the relative amounts of these minerals. The illite content was highest in piedmont plain (P.P) followed by plateau (Pl), river alluvial plain (R.A.P), colluvial alluvial plain (C.A.R) and lowland (L.L) units. Smectite content was highest in Pl followed by P.P, L.L, R.A.P and C.A.P units. Several processes, such as the diversity of weathering rate, biocyclying processes of K accumulation, geomorphologic conditions and soil formation processes, caused significant differences in most K forms in the soils. A wide variation in total K (HF-extractable K) (0.54–1.1%), non-exchangeable K (280–450 mg kg–1) and exchangeable K (217–330 mg kg–1) occurred among the physiographic units, corresponding to variations in their mineralogical compositions, mainly the abundance of illite. Significant differences (P ⩽ 0.05) were found for K, HNO3-extractable K and non-exchangeable K between the soils with large illite contents (30–50%) and with small illite contents (10–30%). A significant positive relationship existed between mineral K and illite content (r2 = 0.85, P ⩽ 0.001) and non-exchangeable K and illite content (r2 = 0.84, P ⩽ 0.001). The results indicated that these pools of K are mainly released from the frayed edges and wedge zones of illite.

The Progression from Optical Light Microscopy to Transmission Electron Microscopy in the Study of Soils

Clay Minerals ◽  
1994 ◽  
Vol 29 (2) ◽  
pp. 247-254 ◽  
Author(s):  
F. Van Oort ◽  
A. G. Jongmans ◽  
A. M. Jaunet
Keyword(s):  
Electron Microscopy ◽  
Clay Mineralogy ◽  
Tem Analysis ◽  
Undisturbed Soil ◽  
Thin Sections ◽  
Transmission Electron ◽  
Ultrathin Sections ◽  
Optical Light Microscopy ◽  
The Impact

AbstractThe use of electron microscopy to study clay microfabrics in thin-sections is discussed. A technique is described to isolate undisturbed microparts of pedofeatures from thin-sections, which are subsequently used for TEM analysis. Re-embedding with a polyester resin of undisturbed, in situ, neoformed clay microfabrics, obtained by microdrilling and preparation of ultrathin sections by microtoming with a diamond knife are emphasized; these steps enable micromorphology, clay mineralogy, microchemical and HRTEM analysis to be performed on one unique microsample of clay fabrics, with conserved micro-organization. Two examples on clay neoformation are presented to demonstrate that this technique can successfully be applied to unravel the impact of mineral alteration and clay neoformation in undisturbed soil samples on a micro- and a nanometer scale.

Contrasted mineralogical composition of the laterite cover on serpentinites of Nkamouna-Kongo, southeast Cameroon

Clay Minerals ◽  
2009 ◽  
Vol 44 (2) ◽  
pp. 221-237 ◽  
Author(s):  
R. Yongue–Fouateu ◽  
M. Yemefack ◽  
A. S. L. Wouatong ◽  
P. D. Ndjigui ◽  
P. Bilong
Keyword(s):  
Electron Microscopy ◽  
Microprobe Analysis ◽  
Clay Mineralogy ◽  
Mineralogical Composition ◽  
Ultramafic Rocks ◽  
Flow Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Close Relationship

AbstractFour drill cores along a lateritic hill in Nkamouna-Kongo (southeast Cameroon) were studied using microprobe analysis, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and infrared spectroscopy. The main objective of the study was to investigate the occurrence of clay silicates while evaluating the Ni-Co content of the laterite for potential mineral exploitation. The thick lateritic profiles (>40 m deep) developed on serpentinized ultramafic rocks have an Fe-rich clayey fraction, with goethite as the main mineralogical constituent and secondary quartz and relicts of magnetite-maghemite as accessory minerals. Silicate clays are less abundant and occur mainly towards the top of the profiles. At the summit of the interfluve, kaolinite and some gibbsite are associated with goethite. Along the slopes, at the bottom of profiles, the weathered bedrock shows the presence of smectite (Fe-beidellite) and kaolinite, probably due to slower water-flow conditions. Towards the top of the profile in the lower clay, ferruginous and upper clay horizons, only kaolinite remains with gibbsite, after the leaching of silica and soluble cations following repeated remobilization-recrystallization processes. At the summit, where the downward movement of water is rapid, no smectite was identified. As a whole, the mineralogical composition of the material varies in close relationship with the drainage, leading to a contrasted clay mineralogy marked by the presence of Fe-beidellite and kaolinite at the bottom, and that of kaolinite and gibbsite at the summit of the profiles.

Evaluation of SmartFlare probe applicability for verification of RNAs in early equine conceptuses, equine dermal fibroblast cells and trophoblastic vesicles

2017 ◽  
Vol 29 (11) ◽  
pp. 2157 ◽  
Author(s):  
S. Budik ◽  
W. Tschulenk ◽  
S. Kummer ◽  
I. Walter ◽  
C. Aurich
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Gold Particle ◽  
Developmental Stages ◽  
Cultured Cells ◽  
Dermal Fibroblast ◽  
Fibroblast Cell ◽  
Cell Types ◽  
Limited Information ◽  
Transmission Electron

Live cell RNA imaging has become an important tool for studying RNA localisation, dynamics and regulation in cultured cells. Limited information is available using these methods in more complex biological systems, such as conceptuses at different developmental stages. So far most of the approaches rely on microinjection of synthetic constructs into oocytes during or before fertilisation. Recently, a new generation of RNA-specific probes has been developed, the so named SmartFlare probes (Merck Millipore). These consist of a central 15-nm gold particle with target-specific DNAs immobilised on its surface. Because of their central gold particle, SmartFlare probes are detectable by transmission electron microscopy. The aim of the present study was to investigate the uptake and distribution of SmartFlare probes in equine conceptuses at developmental stages suitable for embryo transfer (Days 6–10), equine trophoblast vesicles and equine dermal fibroblast cell cultures, and to determine whether differences among these cell types and structures exist. Probe uptake was followed by transmission electron microscopy and fluorescence microscopy. Although the embryonic zona pellucida did not reduce uptake of the probe, the acellular capsule fully inhibited probe internalisation. Nanogold particles were taken up by endocytosis by all cell types examined in a similar manner with regard to time and intracellular migration. They were processed in endosomal compartments and accumulated within lysosomal structures after longer incubation times. In conclusion, the SmartFlare probe is applicable in equine conceptuses, but its use is limited to the developmental stages before the formation of the embryonic capsule.

The energy filtering TEM (EFTEM) in modern biological transmisson Electron Microscopy

1995 ◽  
Vol 53 ◽  
pp. 668-669
Author(s):  
W. Probst ◽  
V.E. Bayer
Keyword(s):  
Electron Microscopy ◽  
Chemical Elements ◽  
Ultrastructural Localization ◽  
Ultrastructural Level ◽  
Limited Information ◽  
Energy Filtering ◽  
Transmission Electron ◽  
New Findings ◽  
Biochemical Analyses ◽  
Selection Of

Modern biological electron microscopy can no longer be a static tool merely describing morphology. In addition to ultrastructural information, insights into the molecular and chemical composition of a sample are needed so that new findings stemming from molecular biological and biochemical analyses can be given meaning in an ultrastructural context. Biological electron microscopy will be an essential tool for future discoveries involving the ultrastructural localization of molecules and chemical elements, and it will provide a means to identify the ultrastructural basis for a variety of reaction mechanisms. Many messenger compounds are currently known which can produce dynamic changes of either a subtle or dramatic nature at the ultrastructural level, but only the most basic of these can be examined using a conventional transmission electron microscope (CTEM). CTEMs provide limited information because they perform conventional imaging and do not employ all the signals available for analysis. Unlike a CTEM, an EFTEM permits the selection of a defined energy (wavelength) of electrons which are then used for imaging.

scholarly journals Characterization of Human Transition Zone Reveals a Putative Progenitor-Enriched Niche of Corneal Endothelium

Cells ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1244 ◽  
Author(s):  
Yam ◽  
Seah ◽  
Yusoff ◽  
Setiawan ◽  
Wahlig ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transition Zone ◽  
Corneal Endothelium ◽  
Vision Loss ◽  
Three Dimensional ◽  
Corneal Edema ◽  
Cell Loss ◽  
Limited Information ◽  
Corneal Hydration ◽  
Transmission Electron

: The corneal endothelium regulates corneal hydration to maintain the transparency of cornea. Lacking regenerative capacity, corneal endothelial cell loss due to aging and diseases can lead to corneal edema and vision loss. There is limited information on the existence of corneal endothelial progenitors. We conducted ultrastructural examinations and expression analyses on the human transition zone (TZ) at the posterior limbus of corneal periphery, to elucidate if the TZ harbored progenitor-like cells, and to reveal their niche characteristics. Within the narrow TZ (~190 μm width), the inner TZ—adjacent to the peripheral endothelium (PE)—contained cells expressing stem/progenitor markers (Sox2, Lgr5, CD34, Pitx2, telomerase). They were located on the inner TZ surface and in its underlying stroma. Lgr5 positive cells projected as multicellular clusters into the PE. Under transmission electron microscopy and serial block face-scanning electron microscopy and three-dimensional (3D) reconstruction, the terminal margin of Descemet’s membrane was inserted beneath the TZ surface, with the distance akin to the inner TZ breadth. Porcine TZ cells were isolated and proliferated into a confluent monolayer and differentiated to cells expressing corneal endothelial markers (ZO1, Na+K+ATPase) on cell surface. In conclusion, we have identified a novel inner TZ containing progenitor-like cells, which could serve the regenerative potential for corneal endothelium.

scholarly journals Evolution of Clays in Cretaceous Marly Series (Álava Block, Basque Cantabrian Basin, Spain): Diagenesis and Detrital Input Control

Minerals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 40 ◽  
Author(s):  
Javier Arostegui ◽  
Xabier Arroyo ◽  
Fernando Nieto ◽  
Blanca Bauluz
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Clay Mineralogy ◽  
Tectonic Deformation ◽  
Total Charge ◽  
Carbonate Sediments ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Input Control ◽  
Diagenetic Evolution

Two stratigraphic sections of carbonate sediments with significant thickness differences and without appreciable tectonic deformation were studied near the trough and on a threshold zone at the Álava Trough. Such characteristics make them appropriate to analyze the influence of a slow progression of the diagenesis over the original clay suite. X Ray Diffraction (XRD), Transmission Electron Microscopy (TEM) and Analytical Electron Microscopy (AEM) techniques were applied in natural and alkylammonium-treated samples. Diagenesis slightly modified the clay mineralogy, the disappearance of smectite, and the variation in the content and ordering of the I/S mixed layer, with burial being the most noteworthy process. The total charge in the 2:1 expandable layers of smectite and I/S shows a slight increase, preferentially located on tetrahedral sheets, with depth. The data suggest a moderate diagenesis grade for the studied materials. The combination of techniques allowed identification of several types of detrital micaceous phases, as well-crystallized K-rich micas, Na-K micas, mica-chlorite stacks, and illites, with an expandable behaviour after the alkylammonium treatment. The total charge of illites did not change with diagenesis, suggesting their detrital origin. This research shows that the detrital assemblage masks the diagenetic evolution in the basin, which indicates the importance of the combination of different techniques to infer correctly the diagenetic grade in a sedimentary basin.

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