The hydroxyl orientations in 31 dioctahedral and trioctahedral 2:1 phyllosilicate structures have been determined by electrostatic energy calculations. These structures included micas, brittle micas, and other related minerals exhibiting ordered as well as disordered cation distributions. The dioctahedral micas and brittle micas were examined with and without the interlayer cation. A range of orientations from 1.3° to 183.3° (the angle ρ between the O-H and (001) measured with respect to the M1 site) were found. The orientations for the dioctahedral structures represent a continuum of values whereas the trioctahedral species exhibit two possible orientations separated by an energy barrier. One orientation is near 90° the other is near 180°. The latter orientation results from a concentration of charge on the interlayer (IC) and tetrahedral (T) sites at the expense of the octahedral (M) sites. A multiple regression analysis of all 31 structures, using as predictors the a and b cell parameters, d001, and the charges for T, IC, M1, and M2 sites, was performed. This analysis indicated that the important factors are the charges for IC, T, and M2 sites. When treated as a separate group, one finds the same factors for the dioctahedral structures. The trioctahedral orientations are determined by the charge on the M2 site and the amount of tetrahedral rotation. Using these two predictor equations, the value of ρ can be estimated with a standard deviation of 4.7° and 2.9° for the dioctahedral and trioctahedral cases, respectively.

A vermiculite (Libby, Montana) sample obtained from the Zonolite company contained mostly coarse-grained separates with only 8–7 per cent clay. The 2–50 μm fraction was used for particle-size reduction studies by wet and dry grinding, and size-fractionated into < 2, 2–5, 5–20 and 20–50 μ sizes. About 18 per cent of the sample was attrited to clay after 64 hr of wet grinding, but as much as 59 per cent of the sample was attrited to clay after only 10 min of dry grinding. There was no evidence of damage to the crystal structure of derived clays or silts except for the 20–50 μm fraction from dry grinding.

The observed CEC values of all the fractions decreased as grinding progressed, except for the 2–5 μm fraction from wet grinding where the CEC increased. The decrease in CEC was attributed to an accumulation of biotite, either as a discrete mineral and/or a mixed-layer assemblage of biotite and vermiculite attrited to the clay fraction. In contrast, the fraction showing an increase in CEC was due to an increased concentration of higher charge-density (CEC) vermiculite. Biotite-free CEC data for vermiculite suggested that, in general, the coarser vermiculite separates had a higher CEC than the finer ones.

The susceptibility of minerals in the Libby vermiculite to cleavage by grinding was: vermiculite > hydrobiotite > biotite.

The addition of a 10% talc internal standard to North Pacific sediments allows the relative abundances of clay minerals to be determined both accurately and precisely by X-ray powder diffractometry. Linear programming can be used to generate factors for converting talc-normalized peak areas to weight percentages; hence, absolute clay-mineral abundances can be estimated. This procedure minimizes residuals (nondiffracting or poorly crystalline components), but its accuracy is untested. Even this procedure results in an average residual of almost 30% for North Pacific sediments; other peak-area to weight conversion schemes generate even larger values.

In general, there is no correlation between clay-mineral abundances estimated from talc-normalized peak areas and abundances derived from the assumption that the sum of smectite, illite, kaolinite, and chlorite is 100%. This accounts for the past difficulties in relating bulk-sediment chemistry to clay mineralogy.

Nitrogen adsorption at 78°K and carbon dioxide sorption at 195°K on homoionic lithium, sodium, caesium, calcium, lanthanum and hexane diammonium saturated montmorillonites have been examined by means of V-n plots. In the case of carbon dioxide, sorption on the lithium saturated clay was used as a standard for comparison of the other samples.

The nitrogen plots indicate that most of the surface area lies in super-micropores of approximately 10 Å equivalent plate separation. Variations between cations are attributed to differences in the structure of the porous matrix formed on drying rather than differences in the degree of entry into quasi-crystalline regions. While the initial sorption of carbon dioxide clearly is influenced by the solvation properties of the cations, the subsequent reversibility of the isotherms and linearity of the V-n plots indicates that for all but the largest cations the same sorption process is occurring on surfaces external to the quasi-crystalline regions

Aluminum-substituted hematites (Fe2−xAlxO3) were synthesized from Fe-Al coprecipitates at pH 5.5, 7.0, and in 10−1, 10−2, and 10−2 M KOH at 70°C. As little as 1 mole % Al suppressed goethite completely at pH 7 whereas in KOH higher Al concentrations were necessary. Al substitution as determined chemically and by XRD line shift was related to Al addition up to a maximum of 16–17 mole %. The relationship between the crystallographic a0 parameter and Al substitution deviated from the Vegard rule. At low substitution crystallinity of the hematites was improved whereas higher substitution impeded crystal growth in the crystallographic z-direction as indicated by differential XRD line broadening. At still higher Al addition crystal growth was strongly retarded. The initial Al-Fe coprecipitate behaved differently from a mechanical mixture of the respective “hydroxides” and was, therefore, considered an aluminous ferrihydrite.

Many online messages now contain emoji – these small images have quickly become an important means of communicating. Yet they have not yet been taken seriously in philosophy of language. In this exploratory paper, I attempt to remedy this neglect by analysing the communicative functions of emoji. I argue that emoji have at least three communicative functions. Firstly, they can serve a replicative function, in that they can play the same role as words and punctuation, thereby replicating the function of existing written communicative devices. Secondly, they can serve a compensatory function, in the sense that they can be used to make up for features of face-to-face conversation which are lost in written online conversation. Thirdly, they can serve supplementary functions, in that we can perform new communicative acts with emoji which we could not previously perform either in written or face-to-face communication.

Trommeslåtter (drum tunes) have played a vital role in Norwegian traditional music for several hundred years. This article examines the development and performance of drum tunes in Norway, with a special focus on the work of Johannes Sundvor in transcribing drum music. We present several examples and analyse tunes from Sundvor’s collection. We also demonstrate how this Norwegian drum tradition is related to a tradition of European military drumming. The article concludes with a discussion of aspects of interpretation and an outline of the status of drum tunes today.

This article examines reactions to the South China Sea and Chagos Marine Protection Area arbitrations under the United Nations Convention on the Law of the Sea (UNCLOS), in particular concerns about the potential widening of Part XV jurisdiction and its impact on the dispute resolution system's consent basis. It argues that assessing the impact of such cases involves a characterization of both the function of Part XV and of international judges. Ultimately, it suggests that the best test of whether UNCLOS case law has gone too far is the reaction of States in designing dispute settlement under the new Agreement under UNCLOS on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction.

A regularly interstratified chlorite/vermiculite occurs in red beds of the East Berlin Formation (Early Jurassic age) in the Connecticut Valley. The mineral is restricted to a 2.5-m wide zone of contact metamorphosed strata adjacent to and underlying the Hampden Basalt. Chemical and X-ray powder diffraction data indicate that the chlorite/vermiculite formed in response to lava-induced elevated temperatures and the availability of magnesium in the muds during and shortly after emplacement of the lava flow. Near the contact, hydrothermal fluids originating from the lava and from the synchronal weathering of basalt fragments by superheated pore waters provided a source of Mg. Further from the contact, magnesium was primarily derived from the thermal dissociation of dolomite. K2O concentrations and the distribution of clay minerals in the red mudstone suggest that the interstratified chlorite/vermiculite formed from preexisting illite or vermiculite as potassium was released and brucitic sheets were incorporated into interlayer positions.