Mysterious long-living ultrahigh-pressure or secondary impact crisis.

High-pressure glass has attracted interest in terms of both its fundamental state under extreme conditions and its possible applications as an advanced material. In this context, natural impact glasses are of considerable interest because they are formed under ultrahigh-pressure and high-temperature (UHPHT) conditions in larger volumes than laboratory fabrication can produce. Studying the UHPHT glasses of the unique giant Kara astrobleme (Russia), we found that the specific geological position of the UHPHT melt glass veins points to an origin from a secondary ultrahigh-pressure (UHP) melt according to the characteristics of the host suevites, which suggest later bottom flow. Here, we propose a fundamentally novel model involving an upward-injected UHP melt complex with complicated multi-level and multi-process differentiation based on observations of the UHP silica glass, single-crystal coesite and related UHP smectite that crystallized from an impact-generated hydrous melt. This model proposes a secondary UHP crisis during the modification stage of the Kara crater formation. The results are very important for addressing fundamental problems in fields as diverse as condensed matter states under extreme pressure and temperature (PT) conditions, material and geological reconstructions of impact structures, water conditions in mineral substances under UHP conditions in the deep Earth, and the duration and magnitude of the catastrophic effects of large asteroid impacts.

Spectroscopic features of ultrahigh-pressure impact glasses of the Kara astrobleme.

The state of substances under ultrahigh pressures and temperatures (UHPHT) now raises a special interest as a matter existing under extreme conditions and as potential new material. Under laboratory conditions only small amounts of micrometer-sized matter are produced at a pressure up to 100 GPa and at room temperature. Simultaneous combination of ultrahigh pressures and temperatures in a lab still requires serious technological effort. Here we describe the composition and structure of the UHPHT vein-like impact glass discovered by us in 2015 on the territory of the Kara astrobleme (Russia) and compare its properties with impact glass from the Ries crater (Germany). A complex of structural and spectroscopic methods presents unusual high pressure marks of structural elements in 8-fold co-ordination that had been described earlier neither in synthetic nor natural glasses. The Kara natural UHPHT glasses being about 70 Ma old have well preserved initial structure, presenting some heterogeneity as a result of partial liquation and crystallization differentiation where an amorphous component is proposed to originate from low level polymerization. Homogeneous parts of the UHPHT glasses can be used to deepened fundamental investigation of a substance under extreme PT conditions and to technological studies for novel material creations.

[The intergroup variability and sex dimorphism in the size of the human dental arches in personal identification]. / Mezhgruppovaia izmenchivost' i polovoi dimorfizm razmerov zubnykh dug chelovake pri identifikatsii lichnosti.

The morphology of dental arch has been studied in representatives of 11 contrast (by anthropological characteristics) ethnic groups from regions of their compact residence. The sampling from each ethnic group consisted of 200 subjects (100 male and 100 female) aged 13-20 years. A total of 4,500 plaster models of dental arches were examined. The results were statistically processed using factor, canonical, discriminant analyses, and multidimensional scanning. The data on the variability and sex dimorphism in the size and shape of dental arches in subjects belonging to different ethnic groups may be practically significant in forensic medical personality identification.

[The medical anthropological study of the bone remains from the Yekaterinburg burial]. / Mediko-antropologicheskoe issledovanie kostnykh ostankov iz Ekaterinburgskogo zakhoroneniia.

Results of medical anthropological expert studies of bone remains of Emperor Nicholas II, his family members, and persons in their attendance are presented. Craniological (including computer photoblending), odontological, osteometric, and spectral methods were sued. Numerous photographs, Imperial Family clothes from museums, soil specimens from Tsarskoe Selo and place of burial were used. Expert studies confirmed previous conclusions on personal identification of skeletons as Nicholas II and four Imperial Family members. Additional proofs of identification of skeleton No. 6 as Great Princess Anastasia Nikolaevna are presented. No remains which could be identified as Cesarevich Alexei Nikolaevich and Great Princess Maria Nikolaevna were found. The so-called "adolescent teeth" are upper teeth of a subject aged 17-18. Rare odontoglyphic characteristics of these teeth permit referring them only to skull No. 6 (Great Princess Anastasia Nikolaevna) but not to an adolescent, specifically, to Cesarevich Alexei Nikolaevich.