Composition and Formation Conditions of Neoproterozoic Phosphorites in the Middle Urals

Lithology and Mineral Resources - Phosphorite breccias compose a 6-m-thick member in the Vendian terrigenous Kernos Formation in the basin of the Mezhevaya Utka and Sylvitsa rivers (Middle Urals)....     

Resonance Properties of Extra-Solar Two-Planet Systems

It is shown for the two-planetary version of the weakly perturbed two-body problem that, in a system defined by a finite part of a Poisson expansion of the averaged Hamiltonian, only one of the three components of the area vector is conserved, corresponding to the longitudes measuring plane. The variability of the other two components is demonstrated in two ways. The first is based on calculating the Poisson bracket of the averaged Hamiltonian and the components of the area vector written in closed form. In the second, an echeloned Poisson series processor (EPSP) is used when calculating the Poisson bracket. The averaged Hamiltonian is taken with accuracy to second order in the small parameter of the problem, and the components of the area vector are expanded in a Poisson series.     

Space projections on solar-terrestrial physics

An overview of the current status of research in the field of solar-terrestrial physics conducted by space agencies of various countries is given. The main results of current (Ulysses, SOHO, TRACE, RHESSI, Hinode, and STEREO) and completed (Coronas-F and others) missions as well as the scientific goals and objectives of space projects being prepared and planned (SDO, Solar Probe, Solar Orbiter, Resonance, Interheliosonde, and others) are presented. The space projects are considered in the context of problems of the Sun—Earth system.     

Experiments with the active impact of steam jet on atmospheric electric field

We present the results of experiments dealing with a study of the effect of artificial vapor-water cloud (VWC) on the atmospheric electric field (AEF). The experiments were performed on September 19, 2006, at Kamchatka heat-and-power water field in the region of the operational Mutnovskaya power plant. We had simultaneously measured the AEF intensity (by three sensors), air electroconductivity, the electric potential of drill hole, and the meteorological parameters in the immediate vicinity of geothermal drill holes, which were opened and closed for duration of the observations. It is found that the dependence of the intensity of the electric filed on the liquid water content in the vapor-water mixture of the drill hole varies throughout the duration of the VWC persistence. Models are proposed and the results of the experiment are discussed.     

Multicolor Photometry of Small Bodies of the Solar System: Performance Potential at the Robophot Telescope

Solar System Research - We consider prospects for investigating asteroids with the multicolor photometric method at the Robophot telescope—a robotic telescope of the Dall–Kirkham system...     

Paleoseismic Fault Trenches as Unique Archives of the White Sea Holocene History

Doklady Earth Sciences - We studied sedimentary archives on the Karelian coast of the White Sea (area of the White Sea Biological Station, Moscow State University) from various...     

Strontium Isotope Composition in Limestones of the Dal’nyaya Taiga Group in the Patom Basin: Vendian Reference Section of Siberia

New data on the 87Sr/86Sr ratio variations in carbonate rocks of the Dal’nyaya Taiga Group in the Vendian reference section (Ura Uplift, Central Siberia) are presented. The 87Sr/86Sr variations correlate with the sequence-stratigraphic scheme reflecting evolution of the paleobasin, δ13C variations, and paleontological data. Limestones with a high (>1050 µg/g) Sr concentration, which do not show any signs of alteration of the Sr isotope system, were used for reconstructing the secular 87Sr/86Sr variations. Increase in the 87Sr/86Sr ratio from 0.70755 to 0.70823 complicated by subordinate fluctuations was established in seawater during the accumulation of the Dal’nyaya Taiga Group carbonate rocks. Duration of the postglacial deposition of the Dal’nyaya Taiga Group is estimated at no less than 14–15 Ma. Secular variations of the 87Sr/86Sr ratio measured in the Dal’nyaya Taiga Group limestones are similar to changes of this ratio after the Marinoan glacial period. The Sr and C isotope correlations suggest a prolonged hiatus between the Dal’nyaya Taiga and Zhuya groups.     

Isotope Fractionation and the Pressure Effect on 18O/16O in Kyanite-Sillimanite-Andalusite Polymorphs (Al2SiO5): Ab-Initio Modelling

Doklady Earth Sciences - The β-factor dependences on temperature upon 18O/16O substitution have been originally deduced in andalusite, sillimanite and kyanite accounting for pressure effect:...