The Effect of Aggregation of Impurity Nitrogen on Diamond X-Ray Luminescence

Two samplings of 65 diamond crystals divided by the intensity of a slow X-ray luminescence component are studied from the Arkhangel’skaya and Karpinskogo-1 pipes. IR and EPR spectroscopies revealed a relationship between the nitrogen A and P2 centers of the diamonds and the presence of a slow X-ray luminescence component. Its absence in most diamonds with high content of P1 (C) centers is explained by the low number of A and P2 centers.     

A new method for primary evaluation of the outlook for rare earth element ores

A new method for primary evaluation of REE ore is based on classification of REE by the level of demand from industry. For their primary evaluation, it is proposed to use an outlook coefficient (K_outl) for REE ores, which is a ratio of the relative amount of critical REE to the relative amount of excess REE: K_outl= (Nd + Eu + Tb + Dy + Er + Y)/REE sum: (Ce + Ho + Tm + Yb + Lu)/REE sum. The use of this coefficient for comparison of REE ores pertaining to various genetic types makes it possible not only to grade newly discovered deposits at the early stage of their study but also to evaluate a possible contribution of well-known deposits, including those currently mined, to output of REE.     

The spectra of three newly discovered high-redshift quasars

Spectra of three high-redshift quasars discovered on low-dispersion objective prism plates were obtained. We present the emission line identifications and redshifts of the objects. Equivalent widths, line widths and low-resolution line profiles are given characterizing the quasar emission region. The Lyα and CIV equivalent widths indicate that the considered quasars are luminous objects at high redshift. Both these equivalent widths are too low by a factor 4, whereas the N V/Lyα ratio is 5 times larger than predicted by the photoionisation models. The line profiles are compared with logarithmic, electron-scattering and Gaussian profiles. In all the spectra rich absorption line systems are evident.     

Dielectric loss in ore-forming chromium spinel at temperatures from 20 to 800 °C

Physical, physicochemical, and mineralogical-petrographic methods have been applied to samples of ophiolite-hosted chromite ore from different deposits and occurrences in the Urals. Temperature dependences of dielectric loss obtained for nine chromite ore samples consisting of 95–98% Cr spinel show prominent peaks indicating a relaxation origin of the loss. The analyzed samples have the loss peaks at different temperatures depending mainly on H = (FeO/Fe₂O₃)^? : (FeO/Fe₂O₃)^??, where (FeO/Fe₂O₃)^? and (FeO/Fe₂O₃)^?? are, respectively, the ferrous/ferric oxide ratios in the samples before and after heating to 800 °C, and H is thus the heating-induced relative change in the FeO/Fe₂O₃ ratio. These peak temperatures vary from 550 °C (sample 1, high-Cr chromium spinel with more than 52% Cr₂O₃) to 750 °C (sample 2, aluminous and magnesian spinel with less than 30% Cr₂O₃), and H ranges correspondingly from 1.61 to 5.49. The temperature of the loss peaks is related with H as H = 34.30 ? 11.52N + 1.20N², with an error of σ = 0.19 (N = T · 10^?2, T is temperature in °C).     

Origin of loess-like silt in Northern Jakutia,USSR

Sediments of different lithological composition of a common feature — a relict system of thick syngenetic ice wedges — are called ice complexes. Three types of ice complex are distinguished in N Jakutia, with different topographic roles. They formed in the second part of the Upper Pleistocene. Author found that it is not the matter of transportation that accounts for the formation of the main features of their composition, but the specifics of lithogenesis first of all determined by the conditions of cryogenic weathering.     

Reconstructions of the Mesozoide structures in the eastern Amur-Okhotsk fold system, Far East

The late Jurassic reconstruction for the Ul’ban synclinorium was proposed based on the lithological and structural similarity of the Upper Permian and Mesozoic complexes of the Yankan-Dzhagdy and Ul’ban lithotectonic zones of the Amur-Okhotsk fold system. It was suggested that the Un’ya-Bom subzone of the Yankan-Dzhagdy LTZ is a fragment of the Ul’ban synclinorium (including its eastern centroclinal closure) that was detached and westward displaced (for 400–600 km) in the first half of the Cretaceous.     

The structural and textural features of felsic volcanics of the Sarbai Formation (Southern Urals)

The results of a microscope study of samples of felsic volcanic rocks from the upper horizons of the Sarbai Formation (O₂–S₁ sb) in the Southern Urals that compose the formation are presented. A detailed study of the samples and an evaluation of the results of a silicate analysis of these rocks showed their volcanogenic genesis. The rocks have been classified as volcanic glass that underwent several stages of transformation. Three newly-formed structural and textural types of mineralization were defined: spherulitic (felsophyric), axiolitic, and felsitic.