The stability of smectite separated from a Houston Black clay soil was studied by solubility methods in an acid environment. High Silicon levels (supersaturated with respect to amorphous Si) probably were due to dissolution of the smectite and slow precipitation of amorphous Silicon. Also, mica and vermiculite impurities may have contributed to high solution Si values. Solubility data from equilibrium solutions of various treatments and chemical structural analyses permitted the formulation of a solubility equation. The ΔG°f for the Houston Black smectite computed from pK values was —2433.9 ± 0.8 kcal/mole. The stability of this clay could then be determined by calculations for any desired solution environment. It was found that under some conditions this soil smectite could be more stable than Belle Fourche and Aberdeen montmorillonites. Therefore, it appears that this soil clay has the required stability area in which it can form in nature.

Fabric refers to the spacial arrangement of clay particles in a sample relative to a reference plane. X-ray diffraction data yield an ‘amount of orientation’ (AO) that varies from zero for ideal random to 100 for ideally oriented fabric. The AO has been related to the average angle of inclination of clay particles to the reference plane.

Fabric data from 50 samples involving 2000 determinations are presented on the effects of: the method of sample preparation prior to one-dimensional consolidation; the magnitude of consolidation stress from 0·1 to over 1000 kg/cm2; changes in direction of consolidation stress; isotropic consolidation; and disturbance during removal of samples from oedometer cells. The single most important variable was the method of sample preparation, as illustrated by the following data on samples consolidated one-dimensionally to 1·5 kg/cm2:clay initially moist, AO = 27 per cent; air-dry clay, AO = 44 per cent; clay slurries, AO = 76–95 per cent. The change in fabric with increasing consolidation stress was most pronounced with samples at very low stresses, the changes in fabric were small for consolidation stress increments usually encountered in engineering practice.

Fabric data provide a very sensitive measure of sample disturbance. Extrusion causes significant disturbance at the center of a 24cm dia, sample cylinder.

Chemical changes during the natural alteration of micas were studied by electron microprobe and classical chemical analyses of fresh and altered portions of mica flakes from 10 Canadian mineral deposits. Results of 50 new analyses are discussed in five examples, starting from simple changes in the interlayer followed by exsolution of titania and ending with complex replacements of anions and cations in all layers of the mica structure. Alteration of micas starts along 001 cleavage planes and fractures and gradually extends into the entire flake leaving some or no remnants of the host mica. The removal of ions from the mica structure and from the flake takes place by gradual depletion, by exsolution of oxides, and/or by alternating removal and redeposition of a newly-formed oxide, illustrated in the following example of the removal of Ti;

1. (1) removal of Ti from the mica structure and exsolution of rutile in the parent mica

2. (2) destruction of rutile and recrystallization as anatase on the surface of the mica; and

3. (3) destruction of anatase, removal of Ti from the surface of the host and crystallization of anatase away from the parent mica.

Residual minerals replacing the original micas are secondary and recrystallized micas, chlorite, vermiculite, serpentine, talc and depleted, optically amorphous flakes. Newly-formed minerals which may incorporate the released ions into their structures are rutile, anatase, sericite, hydronepheline, chlorite-serpentine aggregates, goethite and jarosite. The following partly-altered micas are indicative of sulphide mineralization;

1. (a) bright-green, partly altered phlogopite from ultrabasic rocks and from Co-Cu-Fe-Ni sulphide assemblages. The green phlogopite formed by replacement of K, Al and Ti by Fe, Mg and OH

2. (b) depleted mica coated with jarosite and Ni-goethite in the oxidation zone of a nickel deposit.

   The jarosite formed from released S and Fe from decomposed Fe-Ni sulphides and K released from the host mica; and

3. (c) chlorite-sericite-biotite alteration zones adjacent to Pb-Zn-Cu-Fe deposits.

The author regrets that in the photograph section on p. 50 the caption to the “top” Fig. 2 should read:

Fig. 2(b). Rock sample of attapulgite from Yucatan, Mexico (Tertiary).

the caption on the “bottom” Fig. 2 should read:

Fig. 2(a). Spray-dried attapulgite from Yucatan, Mexico.

Also the bar scales on Fig. 9 were inadvertently juxtapositioned:

Fig. 9(a) should carry the 10 μL scale, and Fig. 9(b) the 1 μ scale.

A 25°C, 1 atm total pressure phase diagram for the system SiO2-AlOOH-Fe2O3-H2O, is determined using the Phase Rule and Shreinemaker’s technique as in Chesworth (1974). The waterpresent assemblages so defined are equivalent to a kaolinitic stage of the goethite facies of the weathering zone. As such they constitute the ideal stable assemblages of several earth-surface deposits and the stage can therefore be used to construct models of these deposits.

The effects of hydrothermal conditions on the sorption and fixation of cesium by various clay minerals and shales were investigated. Hydrothermal heating, which may be expected in a radioactive waste repository, altered the clay minerals and shales and led to a decrease in their cation-exchange capacity. Cesium sorption greatly decreased in micaceous vermiculite and in well-crystallized illites containing vermiculite upon hydrothermal treatment at 400°C and 300 bars pressure due to complete layer collapse. However, poorly crystallized illites heated as above showed either a small increase or only a slight decrease in Cs sorption because of partial layer collapse. These studies show that the decrease in Cs sorption is greater in well-crysallized illites than in poorly crystallized illites when treated similarly under hydrothermal conditions. Hydrothermal heating of Cs-sorbed and Cs-saturated samples increased the amount of Cs fixation in all minerals and shales as a result of collapse of the layers. For example, a sample of the Conasauga shale fixed only 18% of sorbed Cs before treatment but fixed 47% after hydrothermal treatment at 200°C and 300 bars pressure. Thus, hydrothermal conditions in a shale repository may be beneficial after leaked radioactive Cs ions are taken up by clay minerals in shales.

The diffusion of water in the title intercalate has been measured by quasielastic neutron scattering. The diffusion coefficient (6.1 × 10−7 cm2 s−1 at 23.5°C) is one order less than that found previously for a sodium-exchanged montmorillonite which, however, contained 4 times as much water in the interlamellar space. The activation energy for the motion has been deduced to be 18 kJ mol−1. Also it has been demonstrated that upon the time scale of the neutron scattering events (faster than 10−9 s) the hydroxyl groups of the clay lattice are not in motion.

Noncrystalline aluminosilicate gels with Al2O3/(Al2O3 + SiO2) weight ratios from 0.3 to 0.5 were reacted in 0.1 N KOH at temperatures varying from 125° to 175°C. The pH of the solutions dropped sharply with increasing gel:solution ratios, indicating that the coordination number of Al in the products changed from IV to VI. The degree of hydrolysis appeared to be higher with KOH than with NaOH. X-ray powder diffraction and infrared spectroscopy showed that disordered kaolinite was the only crystalline product formed. Thermal data and surface area measurements indicated that the kaolinite was formed by a condensation process.

The adsorption-catalyzed degradation of parathion on clay surfaces is a hydrolysis process, proceeding either directly or through a rearrangement step. The rate and mechanism of degradation are dependent on the nature of the clay, its hydration status, and saturating cation. A mechanism for parathion degradation at adsorption sites on clay surfaces, in the absence of a liquid phase, is proposed.

The School Principal introduces readers to a disillusioned and sarcastic teacher who transitions to the role of school principal in a peripheral primary school. Often regarded as a social criticism treatise rather than a work of art, the novella is characterized by the narrator's pervasive cynicism. However, amidst the sarcasm, the principal's actions reveal a surprising undercurrent of compassion, particularly evident in his interactions with children. This article proposes a compassionate reading of the text, positioning it within the framework of childhood history. The narrative, seen through the lens of childhood history, unveils a cultural shift in Iran during the first half of the 20th century, specifically in the realm of education. It explores the complexities of transitioning from child labor to formal schooling and the evolving perceptions of children as innocent, passive, and dependent. A key conflict in the novella revolves around the clash between Iranian patriarchy and the emerging concept of modern childhood. The principal grapples with adapting to a new model that places children at the center of societal and familial concerns. Despite attempts to prioritize children's welfare, the principal struggles to reconcile the demands of patriarchy with the evolving notion of childhood.

Dehydroxylated sericites were stirred in the various salt solutions, or washed several times with various salt solutions using a centrifuge. By these treatments a seriate of the 2M type was easily transformed into an interstratified mineral of the rectorite type when a sericite was treated with sodium salts, and random mixed-layer mineral was formed from 1M sericite. The formation of a rectorite-type mixed-layer mineral from 2M sericite can be explained by the (OH) bond direction after the extraction of the potassium ions.