Fluctuations of Nero Lake in the Holocene

Doklady Earth Sciences - The paleohydrological settings in the Rostov lowland (Yaroslavl oblast) have been the subject of long-standing of disputes. The concepts for the Holocene fluctuations in...     

Melt Inclusions in Chromium Spinel of Kimberlites of the Zapolyarnaya Pipe,Upper Muna Field,Siberian Craton

Doklady Earth Sciences - The results of study of primary melt inclusions in сhromium spinel of kimberlites of the middle Paleozoic Zapolyarnaya pipe (Upper Muna field, Siberian Craton) are...     

Variations in the sulfur isotopic composition of sulfides from phanerozoic gold-silver deposits

Data on the sulfur isotopic composition of sulfides from gold-silver deposits of volcanoplutonic belts were systematized. The deposits differ in the variation range, character of distribution, and modal values of δ₃₄S. It was shown that the sulfur isotopic composition is an integral parameter related to a combination of geologic factors. Based on the analysis of the compiled database, it was concluded that the sulfur isotopic composition of deposits evolves in time in an oscillatory manner, similar to the periodic variations in the isotopic composition of sulfide and sulfate sulfur in the Earth’s sedimentary shell.     

The late Silurian-Early Devonian natural remanent magnetization of kimberlites and traps in the Yakutian diamondiferous province

Doklady Earth Sciences -     

THE STUDY OF SOIL-VEGETATION DYNAMICS THROUGH REMOTE SENSING

Remote sensing imagery at widely varying scales is used in the analysis of the soil-vegetation cover of the west-central Siberia. Space imagery and smaller-scale air photographs initially are used to divide a study area into basic soil-vegetation complexes based on the criterion of figure outline. The internal structure of the complexes are then analyzed in greater detail, using larger-scale air photographs and a standard interpretation key based on selected field observations. Tonal-textural variations establish the ecological affiliations of separate elements within each complex and their dynamic states at a particular point in time. Translated from: Geografiya i prirodnyye resursy, 1985, No. 2, pp. 112-119.     

The Yakutosirenites armiger Ammonoid Zone of Northeast Asia as a Reference Level of the Boreal-Tethyan Correlation of the Lower Carnian

Problems of the Boreal-Tethyan correlation of the lower Carnian and their potential solutions are discussed. The composition and distribution of ammonoids in the most representative sections of the upper part of the lower Carnian Substage in Northeast Asia, including the northern Okhotsk Region, northern Verkhoyansk Region, and the central part of Kotelnyi Island, are considered. For the first time, the Yakutosirenites armiger ammonoid zone is paleontologically substantiated, and its boundaries in the lower Carnian section in the basin of the Tikhaya River of Kotelnyi Island are defined. The composition of the ammonoid assemblage of the armiger Zone in the studied region is emended and supplemented. It contains, along with the local ammonoid taxa (Yakutosirenites armiger (Vozin), Arctophyllites okhotensis Konstantinov) and rare exotic species of southern origin (Siberioklipsteinia dagysi Konstantinov), the cosmopolitan genus Sirenites. The history of the study and the morphology of the genus Sirenites are considered, and data on its stratigraphic and geographic distribution are summarized. The presence of Sirenites senticosus (Dittmar) and S. ovinus Tozer in the ammonoid assemblage of the armiger Zone of Northeast Asia enables its direct correlation with Tethyan sections, i.e., with the Austrotrachyceras obesum and Sirenites nanseni zones of British Columbia and with the Austrotrachyceras austriacum Zone of the Alpian scale and their equivalents, widespread in many Tethyan regions. This makes it possible to consider the armiger Zone of Northeast Asia as a reference level of the Boreal-Tethyan correlation of the lower Carnian.     

Development of a graphic database for an analytical information system for rapid estimation of gold deposits on the basis of choice of a reference object

This study is aimed at substantiation of the need for use of properties of graphic information in rapid estimation of deposits that are the most similar to reference objects provided with a graphic representation of features and geological situations unknown at a poorly studied expertized object. A technology of graphic database compilation for use in an analytical information system of analogue search is proposed. The system of rapid estimation of gold deposits on the basis of choice of a reference object is supplemented for the first time by a graphic database containing geological data that are necessary for analysis of deposits but cannot be presented in a text or digital form. Taking into consideration the wide development of Internet technologies, the attached HTML file technology, which allows storage of an unlimited number of raster images, was chosen for the control system.     

Mapping urban heat islands of arctic cities using combined data on field measurements and satellite images based on the example of the city of Apatity (Murmansk Oblast)

This article presents the results of a study of the urban heat island (UHI) in the city of Apatity during winter that were obtained according to the data of field meteorological measurements and satellite images. Calculations of the surface layer temperature have been made based on the surface temperature data obtained from satellite images. The experimental data on air temperature were obtained as a result of expeditionary meteorological observations, and the experimental data on surface temperature were obtained based on the data of the space hyperspectral Moderate-Resolution Imaging Spectroradiometer (MODIS) system, channels 31 and 32 (10.78–11.28 and 11.77–12.27 micrometers, respectively). As a result of the analysis of temperature fields, an intensive heat island (up to 3.2°C) has been identified that was estimated based on the underlying surface temperature, and its mean intensity over the observation period significantly exceeds the representative data for European cities in winter. It has also been established that the air temperature calculated according to the MODIS data is systematically higher under winter conditions than the air temperature from direct measurement data.     

Reconstruction of Late Pleistocene events in the periglacial area in the southern part of the East European Plain

An integrated study of the loess–soil sequence in the coastal exposure near the settlement of Beglitsa (Rostov oblast) allowed us, for the first time, to reconstruct the landscape-climatic changes that occurred in the eastern Azov region over the course of the Late Pleistocene. In the south of the periglacial zone, considerable differences between intensity of the loess accumulation in the Early and Late Valdai Cryochrons were revealed. In the Early Valdai Epoch, which corresponds roughly to the end of Marine Isotope Stage (MIS) 5 and MIS 4, loess accumulation occurred after completion of development of the Mezin pedocomplex and before the beginning of the Bryansk stage of soil development, i.e., over more than 20 000 years. In the much shorter Late Valdai Cryochron MIS 2 (10 000–12 000 years), loess accumulation reached 5 m. The data evaluation shows that the loess accumulation rates in the Early Valdai Epoch (~0.07 mm/year) and the Late Valdai Epoch (~0.5 mm/year) differ from each other by an order of magnitude.