Berthierine occurs as pore-linings of well crystallized laths of variable thickness in oil-sands of the Clearwater Formation, Alberta, Canada. Berthierine crystallized early in diagenesis within portions of a deltaic/estuarine complex dominated by brackish to fresh water.

Separates prepared using high gradient magnetic separation contain approximately equal amounts of monoclinic and orthohexagonal berthierine. Minor, but variable, quantities of inseparable, iron-rich impurities mainly consist of chamosite Ib and IIb, and Fe-rich smectitic clays.

Clearwater Formation berthierine has a range of chemical compositions that differ from those reported for most other berthierines. The SiO2 (27-35 wt%), Fe2O3 (5-8 wt%) and Al2O3 (16-18 wt%) contents for Clearwater Formation berthierine fall between values normally reported for berthierine and odinite. The average structural formula of five samples studied in detail is (Fe2+1.01Al0.82Mg0.46Fe3+0.28 Mn<0.01□0.43)(Si1.74Al0.26)O5(OH)4, where □ represents vacancies in the octahedral sheet. The large number of vacancies in the octahedral sheet implies a di-trioctahedral character for this clay. Our results also suggest that a series of compositions can occur between ideal berthierine and odinite end-members.

Berthierine has been preserved within the Clearwater Formation because temperatures during diagenesis did not exceed 70°C, and perhaps also because hydrocarbon emplacement limited subsequent transformation of berthierine to other phases, such as chamosite. Intense, early diagenetic, microbial activity and/ or the strongly reducing environment created by later emplacement of hydrocarbons may be responsible for the Fe2+/Fe3+ ratio of the berthierine. Because of these conditions, this ratio may have changed since initial clay crystallization. The Clearwater Formation occurrence of grain-coating Fe-rich clays provides valuable insights into possible relationships between the Fe-serpentine minerals, odinite and berthierine, and supports an important role for these phases as precursors to the grain-coating and pore-lining Fe-chlorite (chamosite) that is so common in ancient sandstones, including many hydrocarbon reservoirs.

The upper 15−20 m of a 200 m thick lateritic weathering profile on Precambrian itabirites of Capanema, Brazil, reveals a genetic pathway for the formation of hematitic and goethitic nodules in the ferruginous crust through a very fine grain Al-hematite and Al-goethite mixture, called here the brick-red-material (brm). This evolution develops between the soft saprolite and a 10 m thick indurated ferruginous crust. The soft saprolite retains the original structures of the itabirite and is characterized by almost complete dissolution of quartz, the development of goethite septa, and the partial dissolution of primary hematite. Near the contact with the overlying ferruginous crust, the brm is gradually filling voids as well as replacing primary hematite and goethite in the saprolite. In the upper indurated crust, the brm transforms into coarse structureless ferruginous nodules (aluminous hematites and goethites) and is the precursor of the hematito-goethitic nodules of the crusts. Crystallization of newly-formed Al-goethite and Al-hematite within the brm occurs without detectable amounts of amorphous iron oxides of ferrihydrite precursors.

Diffuse Reflectance Fourier Transform Infrared spectroscopy was used to monitor both molecular interactions and concentrations of volatile organic chemicals adsorbed on a commercial montmorillonite. Chemicals tested included propanoic acid, hexanal, heptanal, trimethylamine, dimethylsulfide and dimethyldisulfide. Diffuse Reflectance Fourier Transform Infrared spectroscopy had several advantages over other infrared techniques including ease of sample preparation, greater numbers of useful bands and the ability to detect both major and minor components from the same spectra. Evidence for the formation of organo-clay complexes was found for all chemicals except dimethylsulfide. Spectra of mixed chemicals on the clay showed numerous overlapping bands. Organic concentrations were determined by multicomponent analysis using a least squares curve fitting technique. Significant correlation (P < 0.01) between actual and determined concentrations of added organics was obtained for all except dimethylsulfide. Here the weak spectral contribution appeared to be overshadowed by the strongly adsorbing montmorillonite with consequent decrease in sensitivity. Diffuse Reflectance Fourier Transform Infrared spectroscopy of organo-montmorillonite complexes could be used both as a means of studying molecular interactions and for the determination of adsorbed organic concentrations.

This investigation was carried out to study the effect of different concentrations of citric acid and glycine, which are common in freshwaters, on the kinetics of the adsorption of Hg by kaolinite under various pH conditions. The data indicate that Hg adsorption by kaolinite at different concentrations of citric acid and glycine obeyed multiple first order kinetics. In the absence of the organic acids, the rate constants of the initial fast process were 46 to 75 times faster than those of the slow adsorption process in the pH range of 4.00 to 8.00. Citric acid had a significant retarding effect on both the fast and slow adsorption process at pHs of 6.0 and 8.0. It had a significant promoting effect on the fast and slow adsorption process at pH 4.00. Glycine had a pronounced enhancing effect on the rate of Hg adsorption by kaolinite during the fast process. The rise in pH of the system further increased the effect of glycine on Hg adsorption. The magnitude of the retarding/promoting effect upon the rate of Hg adsorption was evidently dependent upon the pH, structure and functionality of organic acids, and molar ratio of the organic acid/Hg. The data obtained suggest that low-molecular-weight organic acids merit close attention in studying the kinetics and mechanisms of the binding of Hg by sediment particulates and the subsequent food chain contamination.

In Northwestern Mexico, the Miocene basins that disrupted the Sierra Madre Occidental Province are filled with sandstones and conglomerates (the Báucarit Formation) cemented mainly by zeolites of the heulandite-clinoptilolite group. Few volcanic tuffs are intercalated in the sediments for which four different groups of samples have been defined. These groups correspond to a gradation in the alteration of the glassy matrix. Group 1 is characterized by the preservation of the glassy matrix and the presence of disseminated patches of clay minerals with a continuous variation between aluminous Al-montmoril-lonite and ferric smectite end-members. Heulandite-group zeolites and opal C-T are also present. Group 2 is characterized by a nearly complete replacement of volcanic glass by a more homogeneous Al-montmorillonite. In some samples, heulandite-group zeolites are present as clusters on clay minerals. The primary vitroclastic texture is generally preserved and relict glass is present in small amounts. In group 3, the secondary assemblage is dominated by heulandite-group zeolite crystals as pseudomorphs of shards and pumiceous fragments. Discrete illite is present in all samples. Textures are exceptionally well-preserved. Group 4 is characterized by the presence of heulandite and clay minerals in which the Mg-Fe smectite end-member is more magnesian than in other groups. The original texture is not preserved.

The following are deduced from the mass-balance calculations: the alteration of the tuffs leads to a strong Mg- and Ca- and, to a lesser degree, Fe-enrichment, and to Na and K depletion. Zeolites account for Ca-enrichment and clay minerals are host for Fe and Mg. As a consequence, alteration may have occurred under open system conditions and the most likely source for the high Ca and Mg gains is a fluid circulating through the underlying volcaniclastic sediments and underlying mid-Tertiary volcanics of the bimodal (basaltic-rhyolitic) sequence. However, those fluids may have been rather dilute and weakly alkaline.

As estimated temperatures are between 85 and 125°C and as there is only a low burial, it is proposed that hot fluids are responsible for the alteration of volcanic glass. A decrease with time in the initial permeability of the tuffs is consistent with the observed evolution of the changing Al-smectite toward a more magnesian composition.

This report consists of a study of l-ornithine hydrochloride-vermiculite and of benzylammonium hydrochloride-vermiculite complex. The evolution of these organo-vermiculite structures upon heating is studied by X-ray diffraction (XRD) as well as infrared spectroscopy.

After heating vermiculite saturated with 1-ornithine cations, it shows condensation of interlayer ornithine molecules (peptide complexes). The stacking mode, opposing ditrigonal cavities, is not modified between aminoacid complex and peptide complex.

For vermiculite saturated with benzylammonium cations, the stacking sequence changes through heating by changing benzylammonium to NH4+. This transformation implies a sliding of the layers over each other. The ditrigonal surface cavities become face to face, as in the original mica. There are no random translations as in the starting complex.

Three different models have been reported previously to describe the kinetics of the transformation of smectite to illite (Pytte 1982; Velde and Vasseur 1992; Huang et al. 1993). In order to evaluate the general utility of these models to calculate the timing and extent of this transformation, each model was applied to four different geologic settings (Denver Basin, Gulf Coast, the Salton Sea Geothermal System, and Paris Basin) in which the ages, geothermal gradients and potassium ion activities vary markedly. The model results are compared to the measured percentages of illite in illite/smectite (I/S) and the K/Ar ages of I/S (if available) to test the utility of a given model to a particular basin.

Although individual models can be applied to study this transformation within a specific setting, none of these models was successful in simulating the transformation for all four basins. The Salton Sea was simulated best using the model by Huang et al. (1993), which incorporated an increased geothermal gradient during the last 20,000 years. These results indicate that a large fraction of illite formed due to this increased geothermal gradient, and underscores that temperature is a dominant kinetic factor in forming illite. The Denver Basin was simulated well by the models of Velde and Vasseur (1992) and Pytte (1982). The Gulf Coast was simulated very well by the model of Huang et al. (1993) using a term that terminates the transformation at 75% illite. For the Paris Basin, the results are mixed. The models can be refined by comparing the calculated and measured ages of illite such as the K/Ar ages of I/S to understand the thermal history of a particular basin. The calculated ages of illitization derived from these refined models can be used to indicate the time at which source rocks became thermally mature to form oil and gas.

Montmorillonites saturated with small quaternary alkylammonium ions such as tetramethyl-ammonium (TMA) or trimethylphenylammonium (TMPA) are excellent sorbents for aromatic pollutants. In some cases, water inhibits arene sorption, but the inhibition mechanism is not understood completely. The objectives of this study were to determine whether arenes interact with adsorbed TMA and TMPA ions and/or with siloxane surfaces, and how water affects these interactions. We reacted benzene and ethylbenzene vapors with normal- and reduced-charge TMA- and TMPA-montmorillonite films at several relative humidities, and obtained infrared spectra of the resulting sorbate-clay complexes. Arene sorption caused the methyl asymmetric deformation vibrations adsorbed TMA and TMPA to shift to lower wave-number, whereas water sorption caused shifts to higher wavenumber. In the absence of water, benzene and ethylbenzene adsorbed on the siloxane surface as well as interacted directly with TMA and TMPA ions. The proportion of TMA and TMPA ions that interacted with benzene and ethylbenzene was greater for reduced-charge than normal-charge montmorillonite. Comparison of the HOH deformation and cation methyl asymmetric deformation vibrations indicated that both benzene and ethylbenzene inhibited water sorption substantially, and that water more readily displaced benzene and ethylbenzene from TMA and TMPA ions than from siloxane surfaces. Water inhibited arene sorption mainly by hydrating exchangeable cations, thereby obscuring siloxane surfaces adjacent to adsorbed TMA and TMPA ions and decreasing the average pore dimensions. These results indicate that in the presence of bulk water, arene adsorption likely occurs primarily on the siloxane surface.

Helvetic sediments from the northern margin of the Alps in eastern Switzerland were studied by clay mineralogical methods. Based on illite “crystallinity” (Kübier index), the study area is divided into diagenetic zone, anchizone and epizone. Data on the regional distribution of the following index minerals are presented: smectite, kaolinite/smectite mixed-layer phase, kaolinite, pyrophyllite, paragonite, chloritoid, glauconite and stilpnomelane. Isograds for kaolinite/pyrophyllite and glauconite/stilpnomelane are consistent with illite “crystallinity” zones. Using the ordering of mixed-layer illite/smectite, the diagenetic zone is subdivided into three zones. The illite domain size distribution was analyzed using the Warren-Averbach technique. The average illite domain size does not change much within the diagenetic zone, but shows a large increase within the anchizone and epizone. The average illite b0 value indicates conditions of an intermediate-pressure facies series.

The Helvetic nappes show a general increase in diagenetic/metamorphic grade from north to south, and within the Helvetic nappe pile, grade increases from tectonically higher to lower units. However, a discontinuous inverse diagenetic/metamorphic zonation was observed along the Glarus thrust, indicating 5–10 km of offset after metamorphism. In the study area, incipient metamorphism was a late syn- to post-nappe-forming event.

We studied the influence of time ageing (up to 120 d at 50°C or 30d at 95°C) on the mineralogical and chemical composition of hydrolytic species of mixed aluminum and iron samples formed at pH 5.0 and initial Fe/Al molar ratio (Ri) ranging from 0.1 to 10. The partitioning distribution of Fe and Al in soluble or solid phases of different sizes (<0.01, 0.2–0.01, >0.2 μm) depended on Ri and time. The ratio of Fe to Al of the <0.2 μm Fe-Al species of the samples at Ri ≤ 4 slowly increased with time. Usually the higher Ri the higher the amount of Fe + Al present in soluble or very fine solids (<0.2 μm). With time, high percentages of Fe were found mainly in the <0.01 μm while the Al increase in the >0.2 μm sizes. Gibbsite, without the presence of well-crystallized Fe-oxides was formed in the samples at Ri ≤ 0.5 after 7–120 d at 50°C. In the samples at Ri ≥ 1 low-crystalline ferrihydrite was observed after ≥60 d. Only after 120 d did gibbsite or hematite start to form in the samples at Ri = 1–10. However, even after prolonged ageing at 95°C, low-crystalline ferrihydrite was still present at Ri ≤ 4.

The Fe-Al samples at Ri ≥ 1 aged 32 d at 50°C dissolved almost completely by acid ammonium-oxalate (82–93%), but the samples at Ri ≤ 0.5 were only partially solubilized (13–60%). After further 30 d at 95°C, the percentages of Fe + Al solubilized by oxalate from the samples at R ≥ 0.5 was still relatively high (22–39%).

Currently, two commercial plants, operating in the Athabasca region of Alberta, produce approximately 20 percent of Canada's petroleum requirements from oil sands. Surface mined oil sand is treated in a water based separation process that yields large volumes of clay tailings with poor settling and compaction characteristics. Clay particles, suspended in the pond water, interact with salts, dissolved from the oil sands ore, to produce mature fine tailings (MFT) containing only 20 to 50 w/w% solids. As a result, large sedimentation ponds are required to produce enough process water to recycle for the plant. Tailings pond dykes can only be constructed during a short summer season. Consequently, the capability to predict production rate and final volume of MFT is essential for mine planning and tailings disposal operations.

Previous research has demonstrated that a small fraction of nano sized clay particles (20 to 300 nm) effectively controls the bulk properties of MFT. These particles are present in the original ore and become mobilized into the water phase during the oil separation process. In this work, the nano sized particles have been separated from the bulk tailings and subjected to a fundamental study of their flocculation behavior in model tailings water.

Photon correlation spectroscopy and a deuterium NMR method were used to follow particle flocculation and gelation processes. These results were correlated with particle settling data measured under the same conditions. It was determined that the nano particles form fractal flocs that eventually interact to give a thixotropic gel. The ultimate sediment volume produced is almost entirely dependent on the original concentration of nano particles while the rate of water release is governed primarily by electrolyte concentration.

The orientation of TMPA cations on montmorillonite affects the adsorbate-accessible siloxane surface area and determines whether the TMPA phenyl ring can interact with other aromatic adsorbates by π-π interactions. The purpose of this study was to determine the orientation of TMPA ions in the interlayer of normal-charge and reduced-charge Wyoming montmorillonite. The orientation of TMPA's phenyl group was investigated using infrared dichroism of selected aromatic ring vibrations. X-ray diffraction (XRD) and MacEwan Fourier transforms were used to determine interlayer spacings and to ascertain whether reduced-charge Wyoming montmorillonite is a randomly interstratified mixture of layers with two different d-spacings. For normal-charge montmorillonite, the infrared results showed that the C-N bond axis is neither perpendicular nor parallel to the surface, yet X-ray data suggested that the TMPA phenyl ring is perpendicular or nearly perpendicular to the siloxane surface. In this orientation, the average adsorbate-accessible space between adjacent TMPA ions is 24 Å2, or about 1/3 of the total surface. When the phenyl ring of TMPA is perpendicular to the clay surface, aromatic compounds should be able to interact with TMPA's aromatic ring by π-π interactions, while polar compounds such as water can interact with positively charged nitrogen atom. The reduced-charge montmorillonite used in this study is a randomly interstratified mixture of about 25% collapsed layers with no adsorbed cations and 75% expanded layers that are propped open by TMPA's methyl groups, not by the aromatic ring. The adsorbate-accessible surface area on expanded layers of reduced-charge montmorillonite is 1.5 to 2 times that on normal-charge TMPA-clay, depending on the orientation of TMPA's aromatic ring.

Water inhibits sorption of uncharged organic compounds on montmorillonites saturated with small alkylammonium cations such as tetramethylammonium (TMA) and trimethylphenylammonium (TMPA). As a first step toward understanding the mechanism by which water inhibits arene sorption on TMA- and TMPA-montmorillonites, infrared spectroscopy and water sorption isotherm experiments were conducted to determine whether water preferentially hydrates adsorbed TMA and TMPA cations rather than the siloxane surface. Infrared spectra of normal-charge and reduced-charge TMA- and TMPA-montmorillonites were obtained at partial water vapor pressures from 0.075 to 0.92 to determine if water vapor hydrates the adsorbed cations. Water adsorbed at partial pressures from 0 to about 0.2 caused the wave-number position of the HOH deformation vibration of adsorbed water to shift 4 to 10 cm-1 to higher wavenumber and the methyl deformation vibrations of adsorbed TMA and TMPA cations to shift 1 to 2 cm-1 to higher wavenumber, providing evidence that water interacts directly with adsorbed TMA and TMPA ions. There were no shifts in the ring stretching or C-H out-of-plane vibrations of TMPA, which indicates that water interacts with the methyl groups of TMPA, not with TMPA's aromatic ring. Water vapor sorption isotherms showed that normal-charge montmorillonites adsorb more water than do reduced-charge montmorillonites, consistent with the higher concentration of adsorbed cations on normal-charge clay. More water was adsorbed by TMA-montmorillonite than by TMPA-montmorillonite, consistent with the higher hydration energy of TMA. Thus, both the infrared and sorption isotherm results show that water preferentially hydrates adsorbed TMA and TMPA, not the siloxane surface of montmorillonite.