Structures of degassing and fluid transport within the modern zones of the lithosphere destruction in the eastern margin of the Central Asian Fold Belt

The modern geodynamic transformations of the Amur geoblock are related to the activation of pull-apart–strike-slip and simple strike-slip movements. These movements resulted in the formation of destruction zones along ancient transregional fault systems (Nenjiang–Selemdzha, Lermontovka–Belogorsk, West Turan, Khingan, Tan Lu, and others) and young NW- and WE-trending fractures with distinctly expressed shearing displacements. These processes are fixed by earthquakes, focal magmatism, pulsed degassing of the Earth’s interior, and fluid discharge. High-permeability structures confined to the juncture of the destruction zones and young fractures served as the deep degassing drainage systems. These structures are traced by decompaction fields and anomalies of He and other gases. The most contrasting Varvarovka anomaly is located in the northeastern flank of the Yerkovtsy brown coal deposit. The paleogene coal-bearing rocks studied in the Yuzhny quarry within this deposit are characterized by high contents of noble, rare metals, and rare-earth elements, which frequently exceed their average abundances by ten orders of magnitude. Based on assay analysis, the Au content in the coals varies from trace amounts to 4.6 ppm.     

Satellite and Ground-Based Observations of Explosive Eruptions on Zhupanovsky Volcano,Kamchatka, Russia in 2013 and in 2014–2016

The active andesitic Zhupanovsky Volcano consists of four coalesced stratovolcano cones. The historical explosive eruptions of 1940, 1957, and 2014?2016 discharged material from the Priemysh Cone. The recent Zhupanovsky eruptions were studied using satellite data supplied by the Monitoring of Active Volcanoes in Kamchatka and on the Kuril Islands information system (VolSatView), as well as based on video and visual observations of the volcano. The first eruption started on October 22 and lasted until October 24, 2013. Fumaroles situated on the Priemysh western slope were the centers that discharged gas plumes charged with some amount of ash. The next eruption started on June 6, 2014 and lasted until November 20, 2016. The explosive activity of Zhupanovsky was not uniform in 2014–2016, with the ash plumes being detected on satellite images for an approximate total duration of 112 days spread over 17 months. The most vigorous activity was observed between June and October, and in November 2014, with a bright thermal anomaly being nearly constantly seen on satellite images around Priemysh between January and April 2015 and in January–February 2016. The 2014–2016 eruption culminated in explosive events and collapse of parts of the Priemysh Cone on July 12 and 14, November 30, 2015, and on February 12 and November 20, 2016.     

Low-latitude gyrotropic waves in a finite thickness ionospheric conducting layer

The eigen-modes of electromagnetic waves in the finite depth conductive layer of the low ionosphere are considered. The dispersion properties of a discrete set of ULF waves are found taking into account the effect of their damping. The dependence of these properties on the propagation angle relative to the ambient magnetic field is analysed.     

Sorption of Impurity Elements by the Components of Lower–Middle Miocene Lignite from the Sergeevskoe Deposit (Upper Amur Region)

Doklady Earth Sciences - Based on model experiments on the sorption of chemical elements from multicomponent solutions with fungi biomass, lignite, and humic acids, it was assumed that qualitative...     

Early Jurassic Suprasubduction Granitoids of the Uda Complex at the Southwestern End of the Uda–Murgal Magmatic Arc: New Data on the Age and Sources

Doklady Earth Sciences - Granitoids of the Uda complex are developed within the southeastern marginal part of the Siberian craton and its folded framework. Geochemical, isotope–geochemical...     

Age and Sources of Metasedimentary Rocks of the Tokur Terrane of the Mongol–Okhotsk Fold Belt: Results of U–Pb and Lu–Hf Isotope Studies

Doklady Earth Sciences - This paper presents the results of U–Pb (LA-ICP-MS) and Lu–Hf isotope studies of detrital zircons from the presumably Permian meta sedimentary rocks of the...     

Distribution of Cenozoic Metalliferous Coal Deposits in the Zeya–Bureya Sedimentary Basin (Eastern Siberia): Tectonic Reconstruction and Paleogeographical Analysis

Geotectonics - The study has analyzed the distribution of noble metals, rare metals, and rare earth elements in Paleocene and Lower–Middle Miocene coals of the Zeya–Bureya sedimentary...     

Meteor Hazard for Interplanetary Flights in the Ecliptic Plane

Solar System Research - To increase the safety of interplanetary missions, it is necessary to have estimates of the meteor hazard along the flight trajectory. Meteoroid particles of known meteor...     

The First Find of an Ungual Phalanx of a Dromaeosaurid Dinosaur (Dinosauria: Dromaeosauridae) from the Blagoveshchensk Area of Late Cretaceous Dinosaurs (Amur Region,Russia)

Doklady Earth Sciences - An ungual phalanx of a dromaeosaurid dinosaur from near Blagoveshchensk was studied for the first time. The occurrence of dromaeosaurids apart from other taxa of dinosaurs...     

Petrochemistry, geochemistry, and genesis of the Chek-Chikan gabbronorite Massif, southeastern framing of the North Asian craton

The Chek-Chikan Massif is a typical representative of basic magmatism, which is widely spread within the Dzhugdzhur-Stanovoi superterrane. The massif consists of gabbronorites, amphibole gabbros, gabbroanorthosites, and anorthosites. The geochemical similarity of the gabbronorites, amphibole gabbros, and anorthosites suggests their genetic link and allows us to consider them as products of intrachamber differentiation. The main geochemical peculiarity of this rock association is the high degree of the melt fractionation. The rocks of the considered massif are enriched in large ion lithophile elements such as Sr (424–1018 ppm) and Ba (50–754 ppm) and have moderate to low contents of such high-field strength elements as Nb (1–17 ppm), Hf (0.4–1.0 ppm), and Th (0.05–1.14 ppm). According to the model calculations, the initial melt had a basaltic composition and crystallized at a temperature of ∼1180 °C and pressure up to 4 kbar. The U-Pb zircon age of the massif is 203 ± 1 Ma. The geochemical peculiarities of the massif and its confinement to the northern framing of the eastern segment of the Mongol-Okhotsk fold belt make it possible to presume that its formation was related to either the activity of the Siberian plume, to one of the stages of closure of the Mongol-Okhotsk paleoocean in the rear part of subduction zone, or to the slab break off.