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Animal bone remains retrieved from six cremation graves and from layers in the immediate vicinity of damaged graves were subjected to archaeozoological analysis. There were 32 animal bone fragments in total, of which 23 could be identified with high probability in terms of species and anatomy. The remaining bones represent two types. The first, more common type is comprised of bone fragments showing no traces of processing, possibly consumption waste. The second type is that of fragments of damaged artefacts made from osseous material, bearing discernible traces of processing. Among the analysed materials, five fragments revealed traces of processing – two were fragments of combs, another two most likely belonged to one damaged gaming piece (dice), and the last was a small fragment of a polished plate. All these objects were made of deer antler. The remaining, unworked fragments identified in terms of species, which were consumption waste, belonged exclusively to domesticated mammals and birds: sheep, goat, pig, cattle, horse, and hen. They were found in six out of approximately 65 graves recorded in the explored part of the necropolis, which means in 9.2% of the graves. Animal bone remains are interpreted in many ways, could have been the traces of feasts held during the funeral ceremony. The remains could have provided food for the dead on their way to the afterlife or could have been related to some acts of sacrifice.

Pottery from Tell el-Murra Graves

Excavations conducted at the Tell el-Murra cemetery in seasons 2011 and 2012 revealed five graves with pottery assemblages. Grave no. 3 contained pottery vessels which could be dated to the end of the Naqada IIIB period. The pottery vessels found here included two cylindrical jars (one with a cord impression and the second with an incised continuous line beneath the rim), as well as a quite elongated, ovoid jar with impressed halfbows on its shoulders. Two chronologically later graves (nos 1 and 2) should probably be dated to the Naqada IIIC2 period. The pottery assemblage of these graves included large, tall-shouldered jars with impressed halfbows and pot marks (grave no. 1), jars with rope band decorations, wine jars (grave no. 2), ovoid jars, barrel-shaped jars, small broad-shouldered jars, beer jars and undecorated cylindrical jars. Other pottery types included bowls with convex sides, a tray with an oval orifice, a red-polished plate and pot stands. Grave no. 7 seems to date to a different time period, as it contained rough ware beer jars and bowls with convex sides and simple rims. It therefore probably dates to the Naqada IIIC2/IIID period. The most recent of the graves containing pottery vessels (grave no. 5) was discovered in the 2012 season. It contained two pottery vessels: one was a miniature and the other was a bowl with convex sides, a simple rim, a slightly narrowing area of concave contour below the rim and a flat base. Based on pottery analysis, it should be dated to the second half of the 2nd Dynasty.

Diffusion in diamond. II. High-pressure-temperature experiments

High-pressure-temperature (P-T) experiments were conducted in an attempt to determine the diffusion rates of C atoms in diamond, and the possibility of changes in the isotope compositions of diamond at high P-T in the Earth’s mantle. The starting material consisted of a polished plate of natural diamond (very largely 12C), which had been coated with 13C diamond by chemical-vapourdeposition to form a sharp interface between 12C and 13C diamond. Three experiments were performed at 1800, 2000 and 2300ºC, all at 7.7 GPa, for0.5 –20 h. Isotopic profiles obtained by ion microprobe before and after each experiment showed no evidence of relaxation of the sharp interface between 12C and 13C, and so diffusion must have been on a scale less than the ~32 nm depth resolution for this technique. Using 32 nm as the maximum length scale of diffusion across the interface, the maximum ln D (diffusion coefficient) values for the experiments were calculated to be in the range –38 to –42. Unlike previous experimental data, these results show that changes in the isotopic compositions of diamond on long time scales in the Earth’s upper mantle are unlikely. Furthermore, the results support empirical evidence from mapping of C isotope distributions in natural diamonds that C isotope compositions reflect diamond growth compositions.

Diffusion in diamond. I. Carbon isotope mapping of natural diamond

Recent advances in ion microprobe instrumentation and techniques have enabled the mapping of C isotope ratios across the whole of a polished plate of a natural diamond from Guaniamo, Venezuela. The resultant map of C isotope variation closely matches the cathodoluminescence image of the growth structure of the diamond and, therefore, indicates an extremely limited scale of diffusion of C atoms sincethetimeof diamond formation. This result is compatible with thelimite d mobility of N atoms shown by theIaAB aggregation stateof thediamond. Inclusions in thediamond aree clogitic, in common with many Guaniamo diamonds with temperatures of formation of around 1200ºC. At such temperature the IaAB aggregation state indicates a mantle residence time on the order of 1 Ga. Such temperatures of formation and mantle residence times are common to many natural diamonds; thus the extremely limited diffusion of C isotopes shown by the mapping indicates that many diamonds will retain the C isotope compositions of their initial formation.

On the variation of X-ray diffraction contrast with wavelength: A study with synchrotron radiation

Diffraction contrast phenomena on X-ray topographs taken with continuous-spectrum synchrotron radiation have been studied at wavelengths of 0.057, 0.064, 0.071, 0.100, 0.154, 0.206 and 0.250 nm. The specimen was a polished plate of natural diamond with surfaces parallel to (110), ½ mm thick. Using the {\bar 1}11 reflection and a stored electron beam energy of 1.8 GeV all topographs (except that taken with λ = 0.25 nm) were harmonic free. The specimen exhibited mixed-habit growth, containing sectors of normal faceted {111} growth and sectors of non-faceted `cuboid' growth in which growth-surface orientation was variable and only approximately parallel to {100}. Prior to X-ray topography the specimen had received localized damage from implantation with fluorine ions of 17 MeV energy. Features whose variation with wavelength was studied included (1) the relative strengths of integrated reflections from {111} and `cuboid' growth sectors, (2) the intensity of `spike' disorder diffuse reflections relative to sharp Bragg reflections, (3) contrast from inclusions, polishing striae and fracture damage and (4) lattice bending and diffraction contrast at the sites of fluorine ion implantation. Theoretical predictions of the wavelength variation of the intensity of the diffuse reflection images and of contrast due to resolved defects showed good agreement with the observations.

On the contact of smooth surface

In recent years a number of experiments have shown that if a clean optically polished plate is lowered on to a similarly polished plate in air, the two surfaces do not come into contact. The top plate remains “floating” at a distance equal to the thickness of several thousand air molecules above the bottom plate. Thus Hardy and Nottage found that a polished steel cylinder placed on a steel plate remained at a distance of 4 µ above the plate in clean dry air. By applying a pressure to the top cylinder the surfaces could be made to approach more closely, but on removing the pressure the cylinder would again rise to a height of 4 µ . This height remained constant and was the same for glass on glass as for steel on steel. When the air was replaced by various organic substances, e.g. , octane, capryllic acid, octyl alcohol, the distance between the surfaces remained remarkably constant at 4 µ . When the surfaces were contaminated with a trace of palmitic acid the distance was decreased to 2·3 µ . Similarly Watson and Menon using an electrical capacity method found that the distance between polished silver or polished steel plates in air or in oil was approximately 4 µ . Experiments made by Lee are consistent with this. A full discussion of this phenomena is given by Hardy, who considers it to be “the most difficult problem of the boundary state” ( loc.cit ., p. 2). The possibility that the top plate is supported on solid particles was considered in this paper, but the experimental evidence then available argued against it, and it was thought probable that the plate was supported by a film of air or of liquid. To explain this it would be necessary to postulate oriented chains of molecules extending from the surface for several thousand molecules. This is contrary to most physical evidence, which shows that the effect of a surface on a gas does not extend for more than a few molecular layers. The first molecular layer of gas may be oriented and strongly held by the surface, but the degree of orientation decreases very rapidly and becomes inappreciable at a distance of a few molecular diameters from the surface. The point was discussed with Sir William Hardy, and at his suggestion further experimental work was undertaken on this anomalous effect.