Northeast Russia Research Articles

Pseudoconocardium licharewi Zavodowsky, 1960, the latest representative of the extinct class Rostroconchia (Mollusca)

Rostroconchs are one of the “minor classes” of the phylum Mollusca. They were especially diverse in Early and Middle Palaeozoic, but by the end of Late Palaeozoic the group’s diversity had sharply declined. This study shows that rostroconchs completely disappeared from the fossil record before the great end-Permian mass extinction event. The paper offers the first review of all Permian rostroconch localities in Northeast Russia and discusses their possible depositional settings. All records are precisely referenced to the zonal bivalve scale of Northeast Asia, calibrated and correlated with the International Chronostratigraphic Chart using SHRIMP and ID-TIMS dating, taking into account δ13Corg chemostratigraphic data. All Permian rostroconchs in this region are represented by different forms of preservation of the same species — Pseudoconocardium licharewi Zavodowsky, 1960 and are distributed in the interval: the second half of the Artinskian — the lower part of the Changhsingian. Thus, the species in question is the latest known representative of rostroconch in the world. The type series of Pseudoconocardium licharewi, type species of the genus Pseudoconocardium Zavodowsky, 1960, as well as specimens housed in the collection of the Borissiak Paleontological Institute of the Russian Academy of Sciences, are examined. Based on a detailed study of shell morphology, an emended generic diagnosis and a new description are presented here. It is also shown that the genus Pseudoconocardium is monotypic.

The Jurassic through Early Cretaceous Magmatic Belt of the Southern Margin of the Chukotka Terrane, Northeast Russia: New Results of U–Pb Dating of Zircon

The Jurassic through Early Cretaceous Magmatic Belt of the Southern Margin of the Chukotka Terrane, Northeast Russia: New Results of U–Pb Dating of Zircon

Heat Flow in the Northeastern Continental Margin of Russia

Abstract —This work is set out to summarize, analyze and revisit results of the geothermal studies carried out in Northeast Russia. A catalog of measured heat flow values has been compiled, and on its basis a map of the region’s heat flow distribution has been constructed. Geodynamic activity of the tectonic structures in Northeast Russia, their thermal regime in which the heat flow is a critical indicator, is largely determined by the interaction between the Eurasian and North American lithospheric plates and smaller-order plates located in the northeastern part of the Asian continent. The areas of interaction between the Eurasian and North American lithospheric plates are marked by the Arctic-Asian seismic belt, which is characterized by intense orogenesis, modern volcanism, active seismicity, diverse geothermal regimes, and large heterogeneity of measured heat flow values. On the Chukotka Peninsula, the helium isotope method was used to estimate heat flow values. It is proposed to consider the class of geodynamic activity of tectonic structures as one of the factors of the geothermal regime.

The Khangalas Orogenic Au Deposit, Yana–Kolyma Metallogenic Belt (Northeast Russia): Structure, Ore Mineral and Isotopic (O, S, Re, Os, Pb, Ar, and He) Composition, Fluid Regime, and Formation Conditions

The Khangalas Orogenic Au Deposit, Yana–Kolyma Metallogenic Belt (Northeast Russia): Structure, Ore Mineral and Isotopic (O, S, Re, Os, Pb, Ar, and He) Composition, Fluid Regime, and Formation Conditions

<SUP>40</SUP>Ar/<SUP>39</SUP>Ar age of thrusting in sedimentary complexes of Chukotka and Wrangel Island (North-East Russia)

<SUP>40</SUP>Ar/<SUP>39</SUP>Ar age of thrusting in sedimentary complexes of Chukotka and Wrangel Island (North-East Russia)

Indigenous Knowledge for Sustainable Communications and Mobility: Perspectives from the Kolyma Road, Northeast Russia

In northeast Russia, the famous historic Kolyma Road spans two thousand kilometers across two federal subjects of the Russian Federation: the Sakha Republic (Yakutia) and Magadan Oblast. Thousands of people live along and in close proximity to the road, depending on it for communication, mobility, goods, and life support. As the major transportation infrastructure in the entire region, it should be reliable and stable for local communities’ well-being. One strategic approach to ensure its reliability is to acknowledge the role of Indigenous knowledge, which has been neglected despite being established long before the emergence of existing formal systems of communication. Based on data collected through fieldwork, personal observations, and conversations, this paper aims to demonstrate that Indigenous knowledge regarding ways of living, moving, and communicating along and on the road is the key to sustainability in the region. As a result, we claim that this realization should be manifested in designing and implementing communication and mobility systems based on the principles of diversity, equity, and inclusion. In the long term, it is necessary to develop a sustainable road management system for the Kolyma Road to ensure the security and well-being of local communities and for everyone visiting and working on the road.

GEOCRYOLOGICAL CONDITIONS OF THE FORMATION OF GIANT SPRING AUFEIS AT THE ANMANGYNDA RIVER (MAGADAN REGION) ACCORDING TO GEOPHYSICAL DATA

Giant aufeis fields, common in the Northeast of Russia, are the indicators of water exchange processes in cryosphere. The development of ideas about icing processes is relevant both from the fundamental point of view of studying the permafrost evolution, and from the practical point of view – for the development of aufeis hazard measures. The aufeis in the Anmangynda River basin (aufeis glade area 7 km2) is considered representative of the region, and its studies have been carried out since 1962. In 2022, during the period of maximum thawing of the active layer Electrical Resistivity Tomography (ERT) soundings were carried out at the aufeis glade aiming to identify underchannel taliks and flooded fault zones in bedrock, including local areas of groundwater discharge. It was found that within the main river channels there are underchannel taliks up to 30 m deep. According to the results of 2D inversion, local anomalies of low electrical resistivity mark groundwater filtration channels. In 3D geoelectrical models, pipe-like anomalies of low resistivity are identified in the areas of groundwater discharge, interpreted as filtration channels in the alluvium and the zone of exogenous fracturing in bedrock formed by sandy-clay shales, as well as linear vertical anomalies of low resistivity, interpreted as faults. On vertical sections of 3D resistive models, a connection between faults and filtration channels in alluvium and a layer of exogenous fracturing is traced. In the right bank of the valley, geoelectric signs of taliks in the bedrock, presumably associated with fault tectonics, have been established. It is assumed that the identified faults are the additional transit routes for groundwater in the Anmangynda River valley, along with the alluvial aquifer and the zone of exogenous fracturing of bedrock.

REE Mineralization in Alkaline Rhyolites of the Pechalninskii Ore Field (Northeast Russia)

REE Mineralization in Alkaline Rhyolites of the Pechalninskii Ore Field (Northeast Russia)

Conditions of Formation of the Pavlik Gold–Sulfide–Quartz Deposit (Northeast of Russia) According to a Study of Fluid Inclusions

The stockwork gold–sulfide–quartz ores of the Pavlik deposit (northeast of Russia) are formed mainly by homogeneous, low saline (9.4–4.3 wt %-eq. NaCl), essentially water–chloride fluid at temperatures of 275–330°C and a fluid pressure of 600–1840 bar. The fluid is characterized by a rather high CO2 content and a reduced methane content, with the ratio of CO2 : CH4 being 17–37.3. In the fluid, among the cations, the main role is played by Na and Ca, and K and Mg are in a subordinate amount. In addition, many trace elements were detected in the fluid composition: As, Li, Rb, Cs, Mo, Ag, Sb, Cu, Zn, Cd, Pb, U, Ga, Ge, Ti, Mn, Fe, Co, Ni, V, Cr, Y, Zr, Sn, Ba, W, Au, Hg, and rare-earth elements. The obtained data allow us to suppose that there was a decrease in the depth of ore formation during the formation of the deposit by 4–5 km due to the rise of the ore-bearing block. Attention is drawn to the low fluid pressures for a number of samples (330–140 bar), which may be associated with a separate stage of mineral formation. The ore-forming fluid of the Pavlik deposit in composition, temperatures and pressures shows similarities with the fluids of the neighboring Natalka and Rodionovsky deposits and has a great similarity with typical fluids of orogenic gold deposits. The information given in the article is of great practical importance for regional predictive metallogenic constructions, as well as prospecting and evaluation of gold deposits.

Conditions of formation of the Pavlik gold-sulfide-quartz deposit (North-East of Russia), according to the fluid inclusions study

Conditions of formation of the Pavlik gold-sulfide-quartz deposit (North-East of Russia), according to the fluid inclusions study

The Terminal Assemblage of Permian Brachiopods in the Verkhoyanie, Northeast Russia

The Terminal Assemblage of Permian Brachiopods in the Verkhoyanie, Northeast Russia

Traditional nature management in the North as a technological culture of the Arctic subcivilization: from past to future

This article examines thehistorical andcurrent state of the subcivilization in the Russiansector of the Arcticand Subarctic, which is rooted in reindeer husbandry and other forms of environmental-based traditional northern environental management.The preservation anddevelopmentof this subcivilization in modern conditionsis closely linked to the organizational and economic modernization, as well as the technological re-equipment, of all sectors of tradi tional Northern Natural Resource Management. Examples include the biotechnological advancement of traditionalenvironmental managementin the North,which enhances the economic viabilityof its industries while improving the quality of life in the region. Another key resource in Northeast Eurasia is the natural cold, which is a unique and fundamental feature of thecoldest inhabited region ontheplanetwith the lowest temperature and most stable permafrost. The development of modern technologies for preserving permafrostin the conditions of climate change and increased economic activity in the Arctic has the potential to significantly impact the development of subcivilization in the Northeast of Russia.

Подходы к эколого-географической классификации городских озер (на примере г. Якутска)

Based on a methodology, an approach to the ecological and geographical classification of urban lakes is considered on the example of one of the largest cities in the North-East of Russia - Yakutsk. The survey area refers to the permafrost zone, which has a primary influence on the formation and development of lake depressions. The survey objects are based on the largest lakes in Yakutsk. A hierarchical scheme for the formation of lake systems in urbanized territories of the cryolithozone has been developed using the example of lake depressions in the city of Yakutsk. The research includes the following main classifications: morphogenetic, morphometric, hydrological, hydrophysical, hydrochemical and hydrobiological. Based on the above classifications, a unified classification matrix of permafrost lake systems has been compiled, containing descriptive and evaluative characteristics. The selected and most appropriate classifications are conventionally divided into physical-geographical and environmental. As a result of the analysis, the lakes belong to the oxbow-anthropogenic (Beloe, Sergelyakh), erosion-anthropogenic (Saysary) and oxbow-erosion (Khatyng-Yuryakh, Ytyk-Kyuel) type of depressions. Еssentially it is transformed by anthropogenic influences. Thus, as a result of ecological and geographical analysis, the lakes of Yakutsk are classified as moderately polluted (Ytyk-Kyuel, Sergelyakh) and polluted (Beloye, Khatyng-Yuryakh and Sergelyakh).

Reconstruction of climate in the North-East of Russia using dendrochronological methods

The paper presents the results of a dendroclimatic analysis of larch trees growing in the Arctic regions of Northeast Russia. A comparative analysis of dendrochronological parameters and climatic response of generalized regional chronologies was carried out. The results of dendroclimatic analysis showed that different areas have their own characteristics of the radial growth reaction.

Copper Shales of the Prikolymsky Terrane (Northeast of Russia): Mineralogical and Geochemical Features and Ore-Forming Conditions

Copper Shales of the Prikolymsky Terrane (Northeast of Russia): Mineralogical and Geochemical Features and Ore-Forming Conditions

Long-Term Dynamics of the Huge Anmangynda Aufeis in the North-East of Russia (1962–2021)

Long-Term Dynamics of the Huge Anmangynda Aufeis in the North-East of Russia (1962–2021)

The Ages and Isotope Compositions of the Gold–Silver Deposits and Occurrences of the Evensk Group (Okhotsk–Chukotka Volcanogenic Belt, Northeast Russia)

The Ages and Isotope Compositions of the Gold–Silver Deposits and Occurrences of the Evensk Group (Okhotsk–Chukotka Volcanogenic Belt, Northeast Russia)

Species and Coenotic Diversity of the Floodplain Forest Communities in Northeast Russia

Species and Coenotic Diversity of the Floodplain Forest Communities in Northeast Russia

Seismological monitoring of Russia in 2022

The paper presents the results of seismicity monitoring for the main seismically active regions of Russia: the Caucasus, the East European Platform, the Arctic, Altai and Sayan, the Baikal and Transbaikalia; Amur and Primorye; Sakhalin, the Kuril-Okhotsk region, Yakutia, Northeast Russia and Chukotka, Kamchatka and the Commander Islands in 2022. For each region, catalogs of the most significant and perceptible earthquakes are given with the parameters of hypocenters and magnitudes obtained from the processing of instrumental observations. The manifestation of the macroseismic effect from the majority of tangible earthquakes (with I≥2.5 points on the SSI-2017 scale) that occurred on the territory of Russia is analyzed. The materials presented in the manuscript are for informational purposes for specialists in the field of seismology and seismotectonics. It is designed to promptly (before the release of thematic review collections devoted to earthquakes in Russia) to acquaint readers with the available overview information on the seismicity of Russia in 2022.

The First Paleontological Evidence of the Presence of Wordian Bivalves in the Middle Permian of the Omolon Massif (Northeast Russia)

The First Paleontological Evidence of the Presence of Wordian Bivalves in the Middle Permian of the Omolon Massif (Northeast Russia)