Shrilankite Inclusions in Garnets from Kimberlite Bodies and Diamondiferous Volcanic–Sedimentary Rocks of the Yakutian Kimberlite Province,Russia

Pyrope–almandine garnets (Mg# = 28.3–44.9, Ca# = 15.5–21.3) from a heavy mineral concentrate of diamondiferous kimberlites of the largest diamond deposit, the Yubileinaya pipe, along with kimberlite- like rocks and diamondiferous volcano–sediments of the Laptev Sea coast, have been found to contain polymineral, predominantly acicular inclusions, composed of aggregates of shrilankite (Ti₂ZrO₆), rutile, ilmenite, clinopyroxene, and apatite. The presence of shrilankite as an inclusion in garnets from assumed garnet–pyroxene rocks of the lower crust, lifted up by diamond-bearing kimberlite, allows it to be considered as an indicator mineral of kimberlite, which expands the possibilities when searching for kimberlite in the Arctic.     

Synthesis of NH4-Substituted Muscovite at 6.3 GPa and 1000°C: Implications for Nitrogen Transport to the Earth’s Mantle

Doklady Earth Sciences - The synthesis of NH4-bearing muscovite at P = 6.3 GPa and T = 1000°C in equilibrium with NH3–H2O fluid is performed. It is determined that the newly formed...     

The Composition Features of Volatile Components in Diamonds from the Placers in the Northeastern Part of the Siberian Platform by Gas Chromatography–Mass Spectrometry

The primary data are presented on gas chromatography–mass spectrometry of volatile material in diamonds from the placers in the northeast of the Siberian Platform. The new data obtained testify to the crucial role of hydrocarbons and their derivates in the processes of diamond formation within the Earth’s mantle. It was shown that the registered variations in the composition of volatile components in the treated diamonds were caused by a combination of processes including the transformation of redox conditions of the crystallization of diamonds.

     

Evidence for Multistage and Polychronous Alkaline–Ultrabasic Mesozoic Magmatism in the Area of Diamondiferous Placers of the Ebelyakh River Basin (Eastern Slope of the Anabar Shield)

Doklady Earth Sciences - New mineralogical and isotope–geochemical data for zircon megacrysts (n = 48) from alluvium of Kholomolokh Creek (a tributary of the Ebelakh River) are reported....     

Spectral survey of molecular cores NGC 6334I and NGC 6334I(N) in the range 80.5–242.0 GHz

Results of a spectral survey of molecular cores NGC 6334I and NGC 6334I(N) in a number of spectral intervals with widths of about 1000 MHz are presented. Observations were carried out with the SEST radiotelescope. Number of the intervals for NGC 6334I was 11. 209 spectral features were detected towards molecular core NGC 6334I, out of which 203 features were assigned to 25 species.Number of the intervals for NGC 6334I(N) was 6. They represent a subset of the intervals used for the NGC 6334I. The spectrum of NGC 6334I(N) appears to be considerably more poor with the features: 63 features were detected, out of which 55 were assigned to 13 species.Catalogues of assigned features for both sources are presented. They contain the notation of corresponding molecular transition, frequency, and the following observational data: integrated intensity, V_lsr velocity, FWHM and antenna temperature.     

Implementation and integrated numerical modeling of a landslide early warning system: a pilot study in Colombia

Landslide early warning systems (EWS) are an important tool to reduce landslide risks, especially where the potential for structural protection measures is limited. However, design, implementation, and successful operation of a landslide EWS is complex and has not been achieved in many cases. Critical problems are uncertainties related to landslide triggering conditions, successful implementation of emergency protocols, and the response of the local population. We describe here the recent implementation of a landslide EWS for the Combeima valley in Colombia, a region particularly affected by landslide hazards. As in many other cases, an insufficient basis of data (rainfall, soil measurements, landslide event record) and related uncertainties represent a difficult complication. To be able to better assess the influence of the different EWS components, we developed a numerical model that simulates the EWS in a simplified yet integrated way. The results show that the expected landslide-induced losses depend nearly exponentially on the errors in precipitation measurements. Stochastic optimization furthermore suggests an increasing adjustment of the rainfall landslide-triggering threshold for an increasing observation error. These modeling studies are a first step toward a more generic and integrated approach that bears important potential for substantial improvements in design and operation of a landslide EWS.     

Geophysical-geochemical investigation of fire-prone landfills

This paper deals with the integration of electrical resistivity tomography and geochemical methods for studying four different fire-prone landfills. Landfill gas composition (CH₄, H₂S, O₂, CO, CO₂) and subsurface temperature were measured with the constant net 50 × 50 m from the depth 10–60 cm. 28 electrical resistivity tomography lines were surveyed, while Wenner and Sclumberger electrode arrays were employed for all measurements. At the studied sites the landfill gas and temperature measurements mapped gas and temperature anomalies over underground fire sources. 2D electrical resistivity tomography lines, performed over these anomalies, showed these fire sources as high-resistivity zones. The joint employment of the electrical imaging and geochemical survey seems to be a useful tool in carrying out diagnostic investigations at fire-prone landfills.     

Orbital and physical parameters of the spectroscopic binary HD37737

We report the physical and orbital parameters of the visible component of the spectroscopic binary HD37737 (m _V = 8.03). The observations were performed with the 1.2-m telescope of the Kourovka Astronomical Observatory of the Ural Federal University in 2012 and the 6-m BTA telescope of the SAO RAS in 2007 and 2009. Radial velocities were measured separately from each spectral line of the list by the cross-correlation method with a synthetic spectrum. The latter was calculated using the grids of non-LTE model atmospheres with solar chemical compositions. A significant difference in the epochs of observations (2005–2012) allowed to refine the orbital period of the star (7 _· ^d 84705) and the orbital elements of the binary system. We obtained an estimate of the mass function f(m) = 0.23 ± 0.02M _⊙. The best agreement between the synthetic and observed spectra is achieved at T _eff = 30 000 K and log g = 3.50 according to the observations on both instruments. The obtained parameters correspond to a star of spectral type O9.5 III, with mass estimated at 26 ± 2M _⊙. The minimum mass estimate of the secondary component of the binary is 6.2 ± 0.5M _⊙. We have discovered a fact that the velocities, obtained from different spectral lines, differ, which is typical for giant stars. Engaging additional spectra, obtained in 2005 with the 2.1-m KPNO telescope, we investigated the effect of this fact on the estimate of the speed of the system’s center of mass. The difference in the velocities of various lines is approximately the same in the spectra, obtained at all the three instruments. The obtained ratios suggest that the deeper layers of the atmosphere of the star are moving with a greater velocity than the outer layers. Depending on the line, the estimate of the heliocentric velocity of the binary’s center of mass varies in the range from ?11 to 1 km/s.     

A simple predictive model of quartz solubility in water-salt-CO2 systems at temperatures up to 1000 °C and pressures up to 1000 MPa

Knowledge of the solubility of quartz over a broad spectrum of aqueous fluid compositions and T-P conditions is essential to our understanding of water-rock interaction in the Earth’s crust. We propose an equation to compute the molality of aqueous silica, m_SiO2(aq), mol·(kg H₂O)⁻¹, in equilibrium with quartz and water-salt-CO₂ fluids, as follows: