Pb-Pb age and Sr isotopic characteristic of the Middle Riphean phosphorite concretions: The Zigaza-Komarovo Formation of the South Urals

The Pb-Pb age of phosphorite concretions of the Zigaza-Komarovo Formation, which composes the intermediate horizons of the Riphean stratotype of the South Urals, was determined in fractions resulting from the stepwise dissolution of concretions in 0.1 N, 0.5 N, and 1 N HCl. The determination of the Sr isotopic composition in phosphate fractions was favorable for rejection the fractions polluted with extraneous material. On the ²⁰⁷Pb/²⁰⁴Pb-²⁰⁶Pb/²⁰⁴Pb diagram, the isochron based on 31 points corresponds to 1330 ± 20 Ma (MSWD = 1.12), which is in agreement with the stratigraphic position of the Zigaza-Komarovo Formation. The decreased μ₂ value of 9.57 for the phosphorite concretions relative to that of the average earthly lead based on the Stacey-Kramers model (9.74) is related to the rocks with an admixture of mantle lead, which occur in the run-off area of the Zigaza-Komarovo sediments.     

Seismoacoustic field transducer

The possibility of using piezoelectric hydrophones for recording very-low-frequency wave fields is considered. A transducer of seismoacoustic fields with periods over 100 s has been developed and tested.     

Lower riphean low-carbonaceous shales in the southern urals: Raw material for the manufacture of porous rubble

A property of swelling on heating to yield firm lightweight granules has first been revealed for lowcarbonaceous shales (LCS) from the Riphean stratotype in the Bashkirian Megaanticlinorium, Southern Urals. These granules possess all technological properties of “keramzite” or claydite (an artificial, expanded clayey material) and can successfully substitute this material. Moreover, the procedure of their manufacture, analogous to the manufacture of “shungizite” (an artificial carbonaceous-clayey material) from Lower Proterozoic clayey rocks of Karelia, is more economical than that for keramzit. Productive beds of the homogeneous LCS make up extended bodies tens of meters thick. At the present time, they can be used as cover rocks during the exploitation of the Bakal siderite deposits. The LCS represent fine-grained quartz-chlorite-sericite aggregates (with variable relationships between the major components), bearing fine-dispersed shungite in amounts of 0.5–1.0%. High-quality raw material of this kind is characterized by a fine-dispersed admixture of a mixed-layer clayey material bearing montmorillonite and vermiculite. Geological, lithological, mineralogical, and chemical prognostic criteria have been developed for the shungizite raw material. It has been concluded that this construction material, new for the Urals, is promising for industrial use     

The Influence of Moon Phases on the Frequency of Admissions to a Psychiatric Hospital

Izvestiya, Atmospheric and Oceanic Physics - The influence of the moon phase on persons with mental disorders and the frequency of emergency and urgent admissions to the mental hospital in the city...     

Noble metal specialization of Lower and Middle Riphean terrigenous rocks in the South Urals

Results of the study of noble metal specialization of Lower and Middle Riphean terrigenous rocks in the Bashkir Anticlinorium (South Urals) are reported. The study revealed their genetic differences in the relatively unaltered, i.e., “background” terrigenous rocks in type sections of the Burzyan and Yurmatau groups and in sedimentary rocks of the same stratigraphic levels from tectonic zones subjected to local dynamothermal metamorphism of the greenschist facies and intruded by mafic rocks. It has been established that Ru serves as a geochemical marker of the impact of magmatic processes on sedimentary rocks and the redistribution of noble metals during metamorphism and local metasomatism. A generalized model is proposed for the formation of noble metal geochemical specialization of Lower and Middle Riphean terrigenous rocks in the South Urals.     

Results of U–Pb LA–ICP–MS dating of detrital zircons from Ediacaran–Early Cambrian deposits of the eastern part of the Baltic monoclise

Here we present the results of U–Pb LA–ICP–MS dating of detrital zircons from the Ediacaran–Early Cambrian deposits of the eastern part of the Baltic monoclise (Leningrad Region). The obtained age spectra of the detrital zircons suggest that, in the Ediacaran–Early Cambrian, the main clastic material source to the northwest of the Russian Platform was the Baltic Shield. Then in the Early Cambrian along with the Baltic Shield provenance, a clastic source from the Timanian margin of Baltica (northeast in modern coordinates) contributed to the deposits. The obtained data either somewhat set limits of the Timanian orogen formation as older than the previously suggested Middle Cambrian (about 510 Ma), based on the “absence of a Proto–Uralian–Timanian provenance signal” in the Sablino Formation rocks in the south Ladoga, or suggest another rearrangement of detritus transportation paths at the end of Stage 3 (Atdabanian).     

Assessing the efficiency of combined use of surface water and groundwater for process water supply to Kalininskaya NPP

The potential improvement of the reliability of process water supply system is discussed for the case of an important power facility with the use of combined water intake systems. Hydrological simulation is used to determine the deficiency periods of surface water resources and, accordingly, the period of involvement of subsurface compensation water intake. A hydrodynamic model is used to predict the damage to surface runoff caused by the operation of the groundwater intake. The results are used to prepare an operations schedule for the management of combined water intake system.