Influence of clay minerals and organic matter on effects of sodicity on soils

Soil Research ◽  
1993 ◽  
Vol 31 (6) ◽  
pp. 779 ◽  
Author(s):  
GJ Churchman ◽  
JO Skjemstad ◽  
JM Oades
Keyword(s):  
Organic Matter ◽  
Clay Minerals ◽  
Significant Proportion ◽  
Clay Mineralogy ◽  
Soluble Form ◽  
Solution Ph ◽  
Interparticle Interactions ◽  
Sodic Soils ◽  
Colloidal Form ◽  
Exchangeable Al

This review shows that the permeability of soils decrease because exchangeable sodium causes aluminosilicate clay minerals to swell and disperse in water. Among common soil minerals, only smectites with a high percentage of exchangeable Na show extensive swelling. Illites often remain dispersed in solutions of high electrical conductivity, partly because the shapes of their particles prevent strong cohesion. Smectites are often highly mobile, consistent with their small particle sizes. The dispersion of kaolinites varies with solution pH since a significant proportion of their charge can be variable. The sensitivity of soils to pH may be more strongly influenced by other, variably charged components than by the dominant aluminosilicates. Of these, metal oxides, hydroxides and oxyhydroxides can restrain the dispersion of aluminosilicate clay minerals. Organic matter can aid the dispersion of sodic soils while suppressing swelling. It can also be mobilized in a soluble form and probably also in a colloidal form under sodic conditions. Exchangeable Mg enhances dispersion from sodicity, but apparently to a greater extent in illitic soils than in smectitic soils. Exchangeable Al tends to prevent dispersion but the influence of clay mineralogy on its effect is apparently untested. The effect of sodicity upon soils is amplified by fineness of texture and by mechanical disturbance. Studies of soil fabric should increase the current poor understanding of the macroscopic effects of sodicity in terms of interparticle interactions of the pure components.

Relationship between clay mineralogy and exchangeable Al in red and yellow soils from the Islands of Okinawa and Java

Soil Research ◽  
1998 ◽  
Vol 36 (3) ◽  
pp. 411 ◽  
Author(s):  
Mohammad Nurcholis ◽  
Yoshihiro Tokashiki ◽  
Kazuhiro Oya ◽  
Moritaka Shimo ◽  
Nobofumi Miyauchi
Keyword(s):  
Clay Minerals ◽  
Clay Mineralogy ◽  
Clay Content ◽  
Okinawa Island ◽  
Tropical Regions ◽  
Al Content ◽  
Red Soils ◽  
Exchangeable Al ◽  
Acid Reaction ◽  
Soil Clay

Red and yellow soils from tropical regions are generally more mature than their subtropical counterparts. Most of these soils contain kaolin as the dominant clay mineral. Exchangeable aluminium (Al) generally balances permanent negative charges and occupies strongly acidic exchange sites of the soil clay. The objective of this study was to identify those clay minerals that are most highly implicated in contributing exchangeable Al to red and yellow soils collected from the Islands of Okinawa and Java. All soils exhibited an acid reaction but varied in their exchangeable Al content and clay mineralogy. Clay content was high in all Javan soils but varied in those from Okinawa. Javan soils were dominated by kaolinite, and Okinawan soils by an association of illite and halloysite. However, 2 : 1-2 : 1 : 1 intergrades were significant components in both the Oku red soils (Okinawa Island) and the Pamagersari red soils (Java Island). Javan soils were characterised by a more mature (advanced) state of weathering than those from Okinawa. The source of exchangeable Al was halloysite in Okinawan soils and 2 : 1-2 : 1 : 1 intergrades in Javan soils.

scholarly journals The influence of pH on the forms of cadmium in four West Australian soils

Soil Research ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 255 ◽  
Author(s):  
SS Mann ◽  
GSP Ritchie
Keyword(s):  
Organic Matter ◽  
Ammonium Oxalate ◽  
Organic Matter Content ◽  
Matter Content ◽  
Residual Fraction ◽  
Soluble Form ◽  
Solution Ph ◽  
Ph Values ◽  
Adsorption Surface ◽  
Exchangeable Form

The forms of cadmium in soils affect its uptake by plants and hence its potential toxicity to animals and humans. We studied the effect of pH on the forms of native and added Cd in four West Australian soils which differed in their clay, hydrous oxide and organic matter content. The forms of Cd were extracted sequentially by KCl, BaCl2, NaOCl, ammonium oxalate and concentrated acids. The majority of Cd applied to a sandy soil was found in the soluble (KCl) and the exchangeable (BaCl2) forms at all pH values. In the siliceous sand, the proportion of the Cd present in the exchangeable form increased as the soil solution pH increased. However, in the peaty sand, the opposite trend was observed; at pH 5, approximately 50% of the Cd was found in the exchangeable form, while at higher pH values, < 60% was bound to organic matter and 20% was in the soluble form. In soils in which the main adsorption surface was dominated by hydrous oxides (mainly goethite), 50-70% of the Cd was extracted as bound to oxides and as the residual fraction at pH < 5. At pH values > 5, the majority (90%) of it was extracted in these forms. Soils, containing clay (mainly kaolinite) as the major adsorbent, retained Cd mainly in exchangeable form at all pH values and at all the rates of Cd application. At pH > 5, however, some of the Cd was also found in the residual form and bound to organic matter. This work has shown that the form of added Cd in a soil cannot be elucidated by considering the major adsorbing component alone. It is also necessary to know the pH, the presence of other adsorbing surfaces and the rates of applied Cd.

Clay mineralogy and shale instability: an alternative conceptual analysis

Clay Minerals ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 127-145 ◽  
Author(s):  
M. J . Wilson ◽  
L. Wilson
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Significant Proportion ◽  
Clay Mineralogy ◽  
Causative Factor ◽  
Economic Consequences ◽  
Petroleum Exploration ◽  
Diffuse Double Layer ◽  
Mineral Surfaces ◽  
Exploration And Production

AbstractThe instability of shales in drilled formations leads to serious operational problems with major economic consequences for petroleum exploration and production. It is generally agreed that the nature of the clay minerals in shale formations is a primary causative factor leading to their instability, although the exact mechanism involved is more debateable. Currently, the principal cause of shale instability is considered to be volume expansion following the osmotic swelling of Nasmectite. However, illitic and kaolinitic shales may also be unstable, so that interlayer expansion cannot therefore be considered as a universal causative mechanism of shale instability. This review considers alternative scenarios of shale instability where the major clay minerals are smectite, illite, mixed-layer illite-smectite (I/S) and kaolinite respectively. The influence of interacting factors that relate to shale clay mineralogy such as texture, structure and fabric are discussed, as are the pore size distribution and the nature of water in clays and shales and how these change with increasing depth of burial. It is found from the literature that the thickness of the diffuse double layer (DDL) of the aqueous solutions associated with the charged external surfaces of clay minerals is probably of the same order or even thicker than the sizes of a significant proportion of the pores found in shales. In these circumstances, overlap of the DDLs associated with exposed outer surfaces of clay minerals on opposing sides of micropores (<2 nm in diameter) and mesopores (2–50 nm in diameter) in a lithostatically compressed shale would bring about electrostatic repulsion and lead to increased pore/ hydration pressure in smectitic, illitic and even kaolinitic shales. This pressure would be inhibited by the use of more concentrated K-based fluids which effectively shrink the thickness of the DDL towards the clay mineral surfaces in the pore walls. The use of soluble polymers would also encapsulate these clay mineral surfaces and so inhibit their hydration. In this scenario, the locus of action with respect to shale instability and its inhibition is moved from the interlamellar space of the smectitic clays to the charged external surfaces of the various clay minerals bounding the walls of the shale pores.

Particle Size Effects on Concentration of Metals in Lake Erie Bottom Sediments

1984 ◽  
Vol 19 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Alena Mudroch
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Clay Minerals ◽  
Surface Sediment ◽  
Size Effects ◽  
Lake Erie ◽  
Size Fraction ◽  
Mineralogical Composition ◽  
Major Elements ◽  
Sediment Samples

Abstract Surface sediment samples obtained at the offshore and nearshore area of Lake Erie were separated into eight different size fractions ranging from &lt;2 µm to 250 µm. The concentration of major elements (Si, Al, Ca, Mg, K, Na, Fe, Mn and P), metals (Zn, Cu, Cr, Ni, V, Co and Pb) and organic matter was determined together with the mineralogical composition and morphology of the particles in each size fraction. The distribution of the metals in the offshore sediment was bimodal with the majority of the metals divided between the 63 to 250 um size fraction which also contained the highest concentration of organic matter (about 20%) and the &lt;4 µm fraction containing up to 60% of clay minerals. However, the metals in the nearshore sediment were associated mainly with the clay minerals.

THE CLAY MINERALS IN SOME BRITISH COLUMBIA SUBSOILS

1962 ◽  
Vol 42 (2) ◽  
pp. 296-301 ◽  
Author(s):  
J. S. Clark ◽  
J. E. Brydon ◽  
H. J. Hortie
Keyword(s):  
British Columbia ◽  
Diffraction Analysis ◽  
Clay Minerals ◽  
Clay Mineralogy ◽  
X Ray Diffraction ◽  
The South ◽  
Parent Materials ◽  
X Ray ◽  
Northeastern Part ◽  
Montmorillonitic Clay

X-ray diffraction analysis was used to identify the clay minerals present in fourteen subsoil samples that were selected to represent some more important clay-bearing deposits in British Columbia. The clay mineralogy of the subsoils varied considerably but montmorillonitic clay minerals tended to predominate in the water-laid deposits of the south and illite in the soil parent materials of the Interior Plains region of the northeastern part of the Province.

scholarly journals Clay Mineralogy and Geochemistry of the Pockmarked Surface Sediments from the Southwestern Xisha Uplift, South China Sea: Implications for Weathering and Provenance

Geosciences ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 8
Author(s):  
Mei Zhang ◽  
Hongfeng Lu ◽  
Qing Chen ◽  
Gayan Bandara ◽  
Hui Zhang ◽  
...  
Keyword(s):  
South China Sea ◽  
Clay Minerals ◽  
South China ◽  
Surface Sediments ◽  
Northern South China Sea ◽  
Clay Mineralogy ◽  
Xrd Analysis ◽  
Average Weight ◽  
X Ray ◽  
China Sea

In the northern South China Sea, pockmarks are widely distributed on the seabed offshore on the southwestern Xisha Uplift. The mineralogy and geochemistry of the clay minerals and surface sediments from the pockmark field were identified using X-ray diffraction (XRD) analysis and X-ray fluorescence (XRF) analysis to trace the provenance, weathering, and sediment transportation system in the area. The clay minerals are primarily comprised of illite, smectite, kaolinite, and chlorite, showing a distribution of average weight percentages of 35%, 35%, 18%, and 13%, respectively. Based on the surrounding fluvial drainage basins and various transport mechanisms (current or monsoon), illite and chlorite primarily originate from rivers in Taiwan and the Mekong and Red Rivers. Kaolinite primarily originates from the Pearl River, and smectite derived from the Luzon arc system is primarily transported by surface currents with significant influence from the Kuroshio intrusion.

Fractionation of natural algal organic matter and its preservation on the surfaces of clay minerals

2021 ◽  
Vol 213 ◽  
pp. 106235
Author(s):  
Longmeng Wei ◽  
Hongling Bu ◽  
Yanfu Wei ◽  
Honghai Wu ◽  
Gehui Wang ◽  
...  
Keyword(s):  
Organic Matter ◽  
Clay Minerals ◽  
Algal Organic Matter

scholarly journals Remaining phosphorus and sodium fluoride pH in soils with different clay contents and clay mineralogies

2004 ◽  
Vol 39 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Marcelo Eduardo Alves ◽  
Arquimedes Lavorenti
Keyword(s):  
Buffer Capacity ◽  
Ammonium Oxalate ◽  
Clay Mineralogy ◽  
Clay Content ◽  
Response Curves ◽  
Solution Ph ◽  
Ph Values ◽  
Soil Clay ◽  
Soil Clay Content ◽  
Discriminatory Capacity

The remaining phosphorus (Prem) has been used for estimating the phosphorus buffer capacity (PBC) of soils of some Brazilian regions. Furthermore, the remaining phosphorus can also be used for estimating P, S and Zn soil critical levels determined with PBC-sensible extractants and for defining P and S levels to be used not only in P and S adsorption studies but also for the establishment of P and S response curves. The objective of this work was to evaluate the effects of soil clay content and clay mineralogy on Prem and its relationship with pH values measured in saturated NaF solution (pH NaF). Ammonium-oxalate-extractable aluminum exerts the major impacts on both Prem and pH NaF, which, in turn, are less dependent on soil clay content. Although Prem and pH NaF have consistent correlation, the former has a soil-PBC discriminatory capacity much greater than pH NaF.

scholarly journals Nano-scale texture and porosity of organic matter and clay minerals in organic-rich mudrocks

Fuel ◽  
2014 ◽  
Vol 135 ◽  
pp. 359-373 ◽  
Author(s):  
Utpalendu Kuila ◽  
Douglas K. McCarty ◽  
Arkadiusz Derkowski ◽  
Timothy B. Fischer ◽  
Tomasz Topór ◽  
...  
Keyword(s):  
Organic Matter ◽  
Clay Minerals ◽  
Nano Scale
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