ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
A study, held in the Krasnodar Territory in 1994-2002, showed an increasing morbidity in residents of all age-categories. Essential differences in the prevalence of registered pathologies and in the nature of their dynamics were registered in some districts. An optimized structure of hospital beds resulted, in the above Territory, in a reduced quantity of beds, primarily in rural areas, and in their more effective utilization. More rural citizens applied for medical care to urban and territorial patient-care facilities, by 1.5 and 1.4 times respectively. Such reduction of hospital beds is possible only after advancing appropriately the regular medical check-ups and clinical care and after diminishing the need in the treatment of patients at hospitals. The data of sociological questioning of residents and of doctors held in three municipal entities by using the method of monitoring are presented. It was demonstrated that promotion of inter-district diagnostic centers, priority development of regular medical check-ups and purpose-oriented measures of reprofiling the specialized bed funds are topical issues in promoting the municipal medical care.
