Crystal morphology and thermal EMF of pyrites in the western flank of Sukholozhsky gold ore field (Lenski ore area)

The investigated crystal morphology and thermal EMF of pyrites in the western flank of Sukholozsky ore field showed that the pyrite crystals have cubic habitus with a weakly-developed face {210}. The crystal faces {100} and {210} are covered with multiple irregular-oriented growth laminae. It has been determined that pyrites have such a property as p-type conduction and embrace insignificant thermal EMF variations. The results of the research indicated the fact of upper ore zone erosion in the western flank of Sukholozhsky ore field and its area potential at depth

Chronicles of nature calendar, a long-term and large-scale multitaxon database on phenology

We present an extensive, large-scale, long-term and multitaxon database on phenological and climatic variation, involving 506,186 observation dates acquired in 471 localities in Russian Federation, Ukraine, Uzbekistan, Belarus and Kyrgyzstan. The data cover the period 1890-2018, with 96% of the data being from 1960 onwards. The database is rich in plants, birds and climatic events, but also includes insects, amphibians, reptiles and fungi. The database includes multiple events per species, such as the onset days of leaf unfolding and leaf fall for plants, and the days for first spring and last autumn occurrences for birds. The data were acquired using standardized methods by permanent staff of national parks and nature reserves (87% of the data) and members of a phenological observation network (13% of the data). The database is valuable for exploring how species respond in their phenology to climate change. Large-scale analyses of spatial variation in phenological response can help to better predict the consequences of species and community responses to climate change.Peer reviewe

Phenological shifts of abiotic events, producers and consumers across a continent

Ongoing climate change can shift organism phenology in ways that vary depending on species, habitats and climate factors studied. To probe for large-scale patterns in associated phenological change, we use 70,709 observations from six decades of systematic monitoring across the former Union of Soviet Socialist Republics. Among 110 phenological events related to plants, birds, insects, amphibians and fungi, we find a mosaic of change, defying simple predictions of earlier springs, later autumns and stronger changes at higher latitudes and elevations. Site mean temperature emerged as a strong predictor of local phenology, but the magnitude and direction of change varied with trophic level and the relative timing of an event. Beyond temperature-associated variation, we uncover high variation among both sites and years, with some sites being characterized by disproportionately long seasons and others by short ones. Our findings emphasize concerns regarding ecosystem integrity and highlight the difficulty of predicting climate change outcomes. The authors use systematic monitoring across the former USSR to investigate phenological changes across taxa. The long-term mean temperature of a site emerged as a strong predictor of phenological change, with further imprints of trophic level, event timing, site, year and biotic interactions.Peer reviewe

Search for CP violation using T-odd correlations in D-0 -> K+K-pi(+)pi(-) decays

A search for $CP$ violation using $T$-odd correlations is performed using the four-body $D^0 \to K^+K^-\pi^+\pi^-$ decay, selected from semileptonic $B$ decays. The data sample corresponds to integrated luminosities of $1.0\,\text{fb}^{-1}$ and $2.0\,\text{fb}^{-1}$ recorded at the centre-of-mass energies of 7 TeV and 8 TeV, respectively. The $CP$-violating asymmetry $a_{CP}^{T\text{-odd}}$ is measured to be $(0.18\pm 0.29\text{(stat)}\pm 0.04\text{(syst)})\%$. Searches for $CP$ violation in different regions of phase space of the four-body decay, and as a function of the $D^0$ decay time, are also presented. No significant deviation from the $CP$ conservation hypothesis is found

Measurement of CP asymmetry in B-s(0) -> D-s(-/+) K--/+ decays

We report on measurements of the time-dependent CP violating observables in $B^0_s\rightarrow D^{\mp}_s K^{\pm}$ decays using a dataset corresponding to 1.0 fb$^{-1}$ of pp collisions recorded with the LHCb detector. We find the CP violating observables $C_f=0.53\pm0.25\pm0.04$, $A^{\Delta\Gamma}_f=0.37\pm0.42\pm0.20$, $A^{\Delta\Gamma}_{\bar{f}}=0.20\pm0.41\pm0.20$, $S_f=-1.09\pm0.33\pm0.08$, $S_{\bar{f}}=-0.36\pm0.34\pm0.08$, where the uncertainties are statistical and systematic, respectively. We use these observables to make the first measurement of the CKM angle $\gamma$ in $B^0_s\rightarrow D^{\mp}_s K^{\pm}$ decays, finding $\gamma$ = (115$_{-43}^{+28}$)$^\circ$ modulo 180$^\circ$ at 68% CL, where the error contains both statistical and systematic uncertainties.We report on measurements of the time-dependent CP violating observables in B$_{s}^{0}$  → D$_{s}^{∓}$ K$^{±}$ decays using a dataset corresponding to 1.0 fb$^{−1}$ of pp collisions recorded with the LHCb detector. We find the CP violating observables C$_{f}$ = 0.53±0.25±0.04, A$_{f}^{ΔΓ}$  = 0.37 ± 0.42 ± 0.20, ${A}_{\overline{f}}^{\varDelta \varGamma }=0.20\pm 0.41\pm 0.20$ , S$_{f}$ = −1.09±0.33±0.08, ${S}_{\overline{f}}=-0.36\pm 0.34\pm 0.08$ , where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the B$_{s}^{0}$ mixing phase −2β$_{s}$ leads to the first extraction of the CKM angle γ from B$_{s}^{0}$  → D$_{s}^{∓}$ K$^{±}$ decays, finding γ = (115$_{− 43}^{+ 28}$ )° modulo 180° at 68% CL, where the error contains both statistical and systematic uncertainties.We report on measurements of the time-dependent CP violating observables in $B^0_s\rightarrow D^{\mp}_s K^{\pm}$ decays using a dataset corresponding to 1.0 fb$^{-1}$ of pp collisions recorded with the LHCb detector. We find the CP violating observables $C_f=0.53\pm0.25\pm0.04$, $A^{\Delta\Gamma}_f=0.37\pm0.42\pm0.20$, $A^{\Delta\Gamma}_{\bar{f}}=0.20\pm0.41\pm0.20$, $S_f=-1.09\pm0.33\pm0.08$, $S_{\bar{f}}=-0.36\pm0.34\pm0.08$, where the uncertainties are statistical and systematic, respectively. Using these observables together with a recent measurement of the $B^0_s$ mixing phase $-2\beta_s$ leads to the first extraction of the CKM angle $\gamma$ from $B^0_s \rightarrow D^{\mp}_s K^{\pm}$ decays, finding $\gamma$ = (115$_{-43}^{+28}$)$^\circ$ modulo 180$^\circ$ at 68% CL, where the error contains both statistical and systematic uncertainties

Search for the lepton flavour violating decay tau(-) -> mu(-)mu(+)mu(-)

A search for the lepton flavour violating decay $\tau^-\rightarrow\mu^-\mu^+\mu^-$ is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of 1.0 fb$^{−1}$ of proton-proton collisions at a centre-of-mass energy of 7 TeV and 2.0 fb$^{−1}$ at 8 TeV. No evidence is found for a signal, and a limit is set at 90% confidence level on the branching fraction, $\mathcal{B}(\tau^-\rightarrow\mu^-\mu^+\mu^-)<4.6\times10^{−8}$.A search for the lepton flavour violating decay τ$^{−}$ → μ$^{−}$ μ$^{+}$ μ$^{−}$ is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of 1.0 fb$^{−1}$ of proton-proton collisions at a centre-of-mass energy of 7 TeV and 2.0 fb$^{−1}$ at 8 TeV. No evidence is found for a signal, and a limit is set at 90% confidence level on the branching fraction, $\mathrm{\mathcal{B}}\left({\tau}^{-}\to {\mu}^{-}{\mu}^{+}{\mu}^{-}\right)<4.6\times {10}^{-8}$ .A search for the lepton flavour violating decay $\tau^-\to \mu^-\mu^+\mu^-$ is performed with the LHCb experiment. The data sample corresponds to an integrated luminosity of $1.0\mathrm{\,fb}^{-1}$ of proton-proton collisions at a centre-of-mass energy of $7\mathrm{\,Te\kern -0.1em V}$ and $2.0\mathrm{\,fb}^{-1}$ at $8\mathrm{\,Te\kern -0.1em V}$. No evidence is found for a signal, and a limit is set at $90\%$ confidence level on the branching fraction, $\mathcal{B}(\tau^-\to \mu^-\mu^+\mu^-) < 4.6 \times 10^{-8}$

MINERALOGY OF THE ALLOWER GOLD DEPOSIT OF THE R. ZASLONKA (GORNAYA SHORIIA)

Link for citation: Pshenichkin A.Ya., Gavrilov R.Yu. Mineralogy of placer gold deposit of the r. Zaslonka (Gornaya Shoria). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.129-137. In Rus. The relevance of the work is caused by the need to replenish the mineral resource base of gold on the basis of comprehensive information obtained recently using a modern analytical base. Purpose: to study the mineralogical composition of samples of the placer deposit of the river Zaslonka (Gornaya Shoria). Methods: mineralogical studies, crystal morphology, X-ray spectral analysis, scanning electron microscopy. Object: samples of concentrates from the alluvial gold deposit of the Zaslonka river (Gornaya Shoria). Results. The authors carried out the study of the mineralogical composition, including the morphology of gold particles, samples of black concentrates on the MBS-10 binocular microscope and OLYMPUS SZX10 stereomicroscope, and slags after gold melting during the preparation of doré alloy on a Hitachi S-3400N scanning electron microscope. Photomicrographs of various types of gold particles and other minerals were taken. As a result of the research, it was found that the vast majority of gold particles belong to very small (68,71 %), as well as to small (14,69 %) and thin (12,47 %) size classes. Gold concentrates, after enrichment on a flotation table, are weakly radioactive due, apparently, to a thin dissemination of Th-U-containing minerals, which is confirmed by the study of slags on an electron microscope after melting gold during the production of doré alloy, where uranothorite, zircon and gold are found in the form of granular spherules. There are, apparently, three sources of gold entering the placer: 1) gold in the «shirt», covered with dark gray, almost black dense films, which is older gold and probably has a more distant source of drift; 2) gold of medium degree of roundness – flattened and lumpy golden-, dull-yellow and silvery-yellow in color, the sources of formation of which were medium-temperature and medium-distant quartz veins of the area; 3) unrounded golden-yellow gold, formed from nearby quartz weakly gold-bearing veins. The poor mineralogical composition of concentrates (and the almost absence of oxidized sulfide minerals, except for pyrite) indicates the presence of low-sulfide medium-temperature quartz veins with a low content of fine gold in primary ores

Pyrites of west flank of Sukholozhskoe gold ore field (Lensk ore district)

The relevance of the study is caused by the need to introduce new complex methods for predicting gold ore objects into the practice of geological exploration. The aim of the research is to obtain information on crystal morphology, thermos-emf, chemical composition and impurity elements of pyrite from the ore zone of the western flank of the Sukholozhsky ore field. Methods: crystal morphology, thermal electromotive force, X-ray spectral analysis, statistical processing of geochemical data on samples of pyrite crystals taken from the ore zone of the western flank of the Sukholozhsky ore field. Results. It was determined that the studied pyrite crystals are found most often in the form of cubes. Often on crystals there is a poorly developed face {210}. Pyrite is characterized exclusively by a hole type conductivity with a spread of thermal electromotive force values from 27 to 83 mV and close average values within the range of 58,4...67,0 mV. The chemical composition of pyrite crystals differs from their stoichiometric formula, which indicates the occurrence of isomorphic impurities (As) in the mineral structure. X-ray spectral analysis revealed the elements that are constantly present in pyrite: Co, Ni, Cu, Zn, As, Pb. The presence of impurity elements in pyrites, typical for the ores of the Sukhoy Log deposit, and especially As, indicates pyrite synore formation during hydrothermal-metasomatic process and its possible entry in the form of isomorphic impurities into mineral structure. Pyrrhotite, chalcopyrite, sphalerite, galena, arsenopyrite, thorianite are defined as mechanical impurities in pyrite. Based on the study of crystallomorphology, thermal electromotive force, chemical composition of pyrites, and distribution of impurity elements in them, a conclusion was made on the upper ore level of the ore zone erosional section in the western flank of the Sukholozhsky ore field

Typomorphism of pyrites of the Olhovsk-Chibizhek gold field (East Sayan)

Актуальность работы вызвана необходимостью комплексного минералого-геохимического изучения золоторудных месторождений для создания прогнозно-поисковых моделей рудных объектов. Цель: изучение типоморфных свойств пирита (кристалломорфологии, элементов-примесей, термо-эдс) из разнотемпературных минеральных ассоциаций и генераций рудных тел и околорудных метасоматитов золоторудных месторождений Ольховско-Чибижекского рудного поля. Методы: кристалломорфология, термо-эдс, статистическая обработка геохимических данных, пространственное моделирование типоморфных свойств пирита. Результаты. Типоморфные свойства пирита - кристалломорфология, элементы-примеси, термо-эдс - закономерно изменяются в объёме рудных тел месторождений Ольховско-Чибижекского рудного поля и от ранних высокотемпературных минеральных ассоциаций к заключительным этапам формирования месторождений. Пириты месторождений рудного поля представлены в основном кристаллами кубического габитуса, количество кристаллов которого закономерно уменьшается с запада на восток (и волнообразно с глубиной рудных тел с амплитудой волны 200…240 м) от Лысогорского к Медвежьему и Константиновскому месторождениям. Наибольшая комбинационная устойчивость кристаллов пирита у {100}+{210}, {100}+{210}+{111}, а на Лысогорском месторождении - {100}+{321} (более 50 %), где грань {321} в комбинациях кристаллов слабо развита и характерна для низкотемпературных минеральных ассоциаций и верхних частей рудных тел. Пириты рудных тел месторождений обогащены Ag, Pb, Zn, Pt, As и особенно Au, весьма характерных для многих золоторудных объектов Сибири и других регионов. При этом в пиритах верхних частей рудных зон и надрудных ореолов содержатся повышенные концентрации Ag, Ва, Sb, Hg, а пириты средних частей рудных тел и рудных столбов резко обогащены Au, Ag, Cu, Pb, Zn, Bi, Pt, в прикорневых участках и в местах их выклинивания по простиранию и падению в пиритах накапливаются Ni, Cо, U, нередко As. Впервые в пиритах месторождений рудного поля и эфелях Ольховской обогатительной фабрики выявлены повышенные концентрации Pt и Pd. Пириты рудных тел и околорудных метасоматитов месторождений рудного поля имеют преобладающую электронную (Константиновское), электронно-дырочную (Медвежье) или дырочную (Лысогорское) проводимость. С глубиной рудных тел и с запада на восток рудного поля от Лысогорского к Медвежьему и Константиновскому месторождениям закономерно увеличивается электронный тип проводимости пиритов как из продуктивных минеральных ассоциаций, так и из околорудных метасоматитов. На основании выявленных типоморфных признаков пиритов: кристалломорфологии, элементов-примесей и термо-эдс, закономерно изменяющиеся в пространстве и во времени, можно судить об уровне эрозионного среза рудных тел и месторождений, их перспективности на глубину и фланги. Минералогическое картирование по пириту на золото необходимо проводить (в комплексе с другими методами исследования) на всех стадиях геологоразведочных работ.The relevance of the work is caused by the need for a comprehensive mineralogical-geochemical study of gold deposits to create predictive-search models of ore objects. The aim of the research is to study the typomorphic properties of pyrite (crystallomorphology, element-impurities, thermo-emf) from different-temperature mineral associations and generations of ore bodies and near-ore metasomatites of gold ore deposits in the Olkhovsko-Chibizhek ore field. Methods: crystallomorphology, thermo-emf, statistical processing of geochemical data, spatial modeling of typomorphic properties of pyrite. Results. Typomorphic properties of pyrite-crystal - morphology, impurity elements, thermo-emf, naturally vary in the volume of ore bodies in the Olkhovsko-Chibizhek ore field deposits and from early high-temperature mineral associations to the final stages of formation of deposits. Pyrites of deposits of the ore field are mainly represented by crystals of cubic habit, the number of crystals of which regularly decreases from west to east (and wave-like with the depth of ore bodies with wave amplitude 200...240 m) from Lysogorskoe to Medvezhye and Konstantinovskoe deposits. The greatest combination resistance of pyrite crystals in {100}+{210}, {100}+{210}+{111}, and at Lysogorskoe deposit - {100}+{321} (more than 50 %), where the {321} face crystals is poorly developed and is characteristic of lowtemperature mineral associations and upper parts of ore bodies Pyrites of ore bodies of deposits are enriched with Ag, Pb, Zn, Pt, As and especially Au, which are very characteristic for many gold ore objects in Siberia and other regions. In the pyrites of the upper parts of ore zones and overhead haloes, the concentrations of Ag, Ba, Sb, and Hg are high, and the pyrites of the middle parts of ore bodies and ore columns are greatly enriched in Au, Ag, Cu, Pb, Zn, Bi, Pt, in the basal areas and in places of their wedging along the strike and dip in pyrite, Ni, Co, U, often As. Increased concentrations of Pt and Pd were detected in the pyrite deposits of the ore field and in the ephes of the Olkhov concentrator. Pyrites of ore bodies and ore metasomatites of ore field deposits have predominant electronic (Konstantinovskoe), electron-hole (Medvezhye) or hole (Lysogorskoe) conductivity. With the depth of ore bodies and from the west to the east of the ore field from Lysogorskoe to Medvezhye and Konstantinovskoe deposits, the electronic type of conductivity of pyrites naturally increases, both from productive mineral associations and from near-ore metasomatites. Based on the revealed typomorphic features of pyrite: crystallomorphology, element-impurities and thermo-emf, regularly changing in space and time, one can judge the level of erosion cut of ore bodies and deposits, their prospects to depth and flanks. Mineralogical mapping of pyrite to gold must be carried out (in conjunction with other methods of investigation) at all stages of geological exploration