Northern Siberia Research Articles

Structural-crystallochemical features of minerals of the glauconite-illite series with high Mg contents from Upper Proterozoic deposits of Eastern and Northern Siberia

At the current level of research, a generalization of previously studied and new lithological-mineralogical and structural-crystal-chemical characteristics of globular phyllosilicates (GPS) of the glauconite-illite series with a high Mg content from Upper Proterozoic sections of Eastern and Northern Siberia (Uchur-May region, Anabar uplift) has been carried out. The classification of glauconite-illite minerals was carried out in accordance with the recommendations of the International Nomenclature Committees for mica and clay minerals, as well as on the basis of literature and our own data. The degree of aluminum content of minerals (КAl = VIAl / [VIFe3+ + VIAl]) of the glauconite-illite series varies from 0.40 to 0.85, the content of Mg and K cations varies from 0.51 to 0.75 and from 0.63 to 0.80 f.u. (formula units), respectively. Using X-ray modeling method of diffraction patterns of oriented and non-oriented preparations of Upper Proterozoic GPS, the following were determined: the content of swelling layers (4–10%), their types (mica, smectite, chlorite), the nature of the alternation (short-range order factor R = 0), unit cell parameters csinβ, ccosß/a, average value of parameter b (9.018–9.074 Å). The conditions of glauconite formation in the Upper Proterozoic basins are considered, their influence on the structural and crystal-chemical features of magnesian hydrocarbons is discussed.

Structural and Crystal-Chemical Features of Mg-Rich Minerals of the Glauconite–Illite Series from Upper Proterozoic Deposits in Eastern and Northern Siberia

Structural and Crystal-Chemical Features of Mg-Rich Minerals of the Glauconite–Illite Series from Upper Proterozoic Deposits in Eastern and Northern Siberia

Ngytarma and Ngamteru: Concepts of the Dead and (Non)Interactions with Them in Northern Siberia

This article examines some features of the mythological beliefs and funeral rites of Siberia’s two related Uralic peoples—the Nenets and the Nganasans. The afterlife fate in the mythology of Nenets and Nganasans is similar—the souls of the dead go to the Lower World, where they continue to live as they lived on Earth. However, the two cultures’ attitudes towards the dead have intriguing differences. A comparison of Nenets and Nganasan beliefs and rituals reveals significant correspondences between the ideas about the benevolence of the dead (the Nenets) or their harmfulness (the Nganasans), on the one hand, and the presence of the practices of substitutional incarnation (images of the dead) (the Nenets) or the absence of such images (the Nganasans) on the other. The differences between the Nenets and the Nganasans, as I suggest, are due to the origin and history of the peoples: the Nenets’ customs reflect the traditions of the Uralic tribes who came to the far north from Southern Siberia in ancient times. At the same time, the Nganasans’ ideas are probably rooted in typical concepts of the Palaeo-Siberian population assimilated by the Uralic tribes.

Ammonoid and coleoid jaws from the Upper Cretaceous of northern Siberia (Nizhnyaya Agapa River sections)

The jaws of cephalopods, ammonites and especially coleoids, are rarely met in fossil state. The localities with diversified jaws, belonging to various groups of fossil cephalopods are even less common. We describe a diversified complex of cephalopod jaws from the upper Cenomanian–middle Turonian of Northern Siberia, which include the upper and lower jaws of Placenticeras ammonites (the oldest placenticeratid jaws known to date) and large-sized jaws of octobrachian coleoids. Although the lower jaws of Placenticeras belong to the aptychus type of ammonoid jaw apparatuses, they are characterized by the thickening of an inner organic layer in their anterior part, with a shape resembling a calcified conchorhynch known in the anterior portion of the lower jaws of Mesozoic nautilids and lytoceratid and phylloceratid ammonoids. The presence a conchorhynch-like structure supports the assumption that the feeding function in placenticeratid lower jaws most likely prevailed over the protective one. The upper jaws of Placenticeras show structure, typical for the jaws of aptychophoran ammonites: an inner lamella, divided into two wings, and a pointed outer lamella. Large-sized upper jaws of octobrachian coleoids demonstrate close affinities with the jaws of Octopoda suggesting that they could have belonged to representatives of this order, probably to large-sized gladius-bearing teudopseins. Judging by the jaws' size, both ammonites and octobrachians, which inhabited the marine basin in the Northern Siberia, were characterized by large body size. The cephalopod assemblage remained unchanged throughout the end of the Cenomanian and the first half of the Turonian.

Digital topographic analysis and lineament interpretation south of the Lena Delta, North Siberia: Landscape expression of its tectonic activity

This study applies semi-automated techniques to analyze the landforms, morphostructure, and geology of the Kharaulakh and Chekanovsky sectors, south of the Lena Delta, northern Siberia. High-resolution data, including TanDEM-X 30 m spatial resolution Digital Elevation Models (DEM), 2 m spatial resolution ArcticDEM Digital Surface Models (DSM), and Sentinel-2 satellite imagery, serve as the basis for the analysis. Digital terrain classification and identification of tectonic lineaments are performed using the Benthic Terrain Modeler (BTM) and Linear Extraction (LINE) algorithm, respectively. Additionally, a hypsometric analysis is conducted to assess areas of potential neotectonic activity. 873 lineaments are identified, primarily in NE-SW and E-W orientations. NW-SE lineaments perpendicular to the lithological and fold belt strikes in the Kharaulakh Ridge suggest inheritance from original depositional settings or later compressional tectonics, now appearing as valleys and weak zones facilitating erosion and river incision. Longer N-S or NNW-SSE lineaments in the Kharaulakh Sector are associated with thrust sheets of the Verkhoyansk fold-and-thrust belt and Cenozoic graben structures linked to the formation of the Laptev Sea Rift System and ongoing regional deformation. The Chekanovsky Sector, marked by epiplatform blocks and hills, presents a dissected plateau with steep valleys. Here, high hypsometric integral values are attributed to compression and uplift near the southwestern boundary of the Laptev Sea Microplate.

Полиморфизм генa TP53 (rs1042522) и особенности иммунного профиля у детей, проживающих в условиях аэрогенной экспозиции бенз(а)пиреном

Examining peculiarities of an immune profile and genetic polymorphisms is especially relevant when identifying markers of effect and sensitivity to exposure to benzo(a)pyrene in northern areas. We examined 1253 children who lived in industrial centers and on conditionally clean territories in the north and south of Eastern Siberia. Levels of benzo(a)pyrene in ambient air and in children’s blood were determined by using HPLC. TP53 (rs1042522) polymorphism was examined by using real-time PCR; p53 levels were identified with flow cytofluorometry; IgG to benzo(a)pyrene, by the radioallergosorbent tests. Exposure of children in Northern Siberia to airborne benzo(a)pyrene at the dose of 7.11•10-3 µg/(kg•day) causes ben-zo(a)pyrene contamination in blood, activates apoptosis (p53) and stimulates occurrence of specific sensitization (IgG to benzo(a)pyrene) (p < 0.05). Similar disorders were established in children in Southern Siberia under exposure to airborne benzo(a)pyrene at the dose of 86.46•10-3 µg/(kg•day). The detected changes in immune profiles of children living in Northern Siberia are associated with G-allele and GG-genotype (rs1042522) of the TP53 gene (OR = 1.37–1.83, p < 0.05); children in Southern Siberia, С-allele and СС-genotype of the said gene (OR = 1.55–2.38, p < 0.05). Therefore, the immune profile of children exposed to airborne benzo(a)pyrene at the dose of 7.11•10-3 µg/(kg•day) in Northern Siberia bears some signs of activated apoptosis (p53) and specific sensitization (IgG to benzo(a)pyrene) associated with G-allele and GG-genotype of the TP53 gene (rs1042522) (OR = 1.37–1.83, p < 0.05). These identified changes in the immune profile are comparable with effects produced by exposure to airborne benzo(a)pyrene at the dose of 86.46•10-3 µg/(kg•day) in Southern Siberia, which are associated with С-allele and СС-genotype of the same gene (OR = 1.55–2.38, p < 0.05). This confirms a hypothesis that effects of technogenic chemical factors can be modulated by specific climatic conditions in northern areas and a contribution made by genetic predisposition. Their combined effect creates a serious risk of developing impairments in an immune profile (OR = 1.37–1.83, p < 0.05; RR = 1.17; 95 % CI: 1.07–1.27) even under low-dose exposure to airborne benzo(a)pyrene.

Polymorphism of TP53 (rs1042522) gene and peculiarities of the immune profile in children exposed to airborne benzo(a)pyrene

Examining peculiarities of an immune profile and genetic polymorphisms is especially relevant when identifying markers of effect and sensitivity to exposure to benzo(a)pyrene in northern areas. We examined 1253 children who lived in industrial centers and on conditionally clean territories in the north and south of Eastern Siberia. Levels of benzo(a)pyrene in ambient air and in children’s blood were determined by using HPLC. TP53 (rs1042522) polymorphism was examined by using real-time PCR; p53 levels were identified with flow cytofluorometry; IgG to benzo(a)pyrene, by the radioallergosorbent tests. Exposure of children in Northern Siberia to airborne benzo(a)pyrene at the dose of 7.11•10-3 µg/(kg•day) causes ben-zo(a)pyrene contamination in blood, activates apoptosis (p53) and stimulates occurrence of specific sensitization (IgG to benzo(a)pyrene) (p < 0.05). Similar disorders were established in children in Southern Siberia under exposure to airborne benzo(a)pyrene at the dose of 86.46•10-3 µg/(kg•day). The detected changes in immune profiles of children living in Northern Siberia are associated with G-allele and GG-genotype (rs1042522) of the TP53 gene (OR = 1.37–1.83, p < 0.05); children in Southern Siberia, С-allele and СС-genotype of the said gene (OR = 1.55–2.38, p < 0.05). Therefore, the immune profile of children exposed to airborne benzo(a)pyrene at the dose of 7.11•10-3 µg/(kg•day) in Northern Siberia bears some signs of activated apoptosis (p53) and specific sensitization (IgG to benzo(a)pyrene) associated with G-allele and GG-genotype of the TP53 gene (rs1042522) (OR = 1.37–1.83, p < 0.05). These identified changes in the immune profile are comparable with effects produced by exposure to airborne benzo(a)pyrene at the dose of 86.46•10-3 µg/(kg•day) in Southern Siberia, which are associated with С-allele and СС-genotype of the same gene (OR = 1.55–2.38, p < 0.05). This confirms a hypothesis that effects of technogenic chemical factors can be modulated by specific climatic conditions in northern areas and a contribution made by genetic predisposition. Their combined effect creates a serious risk of developing impairments in an immune profile (OR = 1.37–1.83, p < 0.05; RR = 1.17; 95 % CI: 1.07–1.27) even under low-dose exposure to airborne benzo(a)pyrene.

Detection of two species of non-indigenous freshwater snails in Arctic Siberia

ABSTRACT Some species of freshwater gastropods, known for their adaptability and resilience, have gained attention globally as invasive species. However, to date, only one invasive population of freshwater snails has been documented beyond the Arctic Circle. In this study, we report the discovery of two non-indigenous species, Planorbella duryi (Wetherby, 1879) and Physella acuta (Draparnaud, 1805), north of 69°N in the Norilsk Industrial District (Central Siberia). Their identification was based on morphological features and COI gene sequences. Both species are native to the temperate and subtropical zones of North America and may have entered the Arctic Asian reservoirs through aquarium introductions. The distribution of these populations is constrained to areas affected by thermal pollution, and their further spread into pristine reservoirs of Northern Siberia is unlikely.

Quantitative methods for reconstruction of the Holocene paleoclimatic characteristics and vegetation changes based on palynological data from lake and peat sediments

The paper presents the results of a methodological study of the quantitative reconstruction of paleoclimatic characteristics (mean January and July temperatures, mean annual temperature and precipitation) and forest cover within a 20 km radius of the study site using palynological data from lake and peat sediments. The following quantitative methods have been tested: the best modern analog technique, transfer functions as weighted averaging, weighted averaging partial least square, and the Random Forest method, a meta estimator that fits a number of decision tree classifiers on various sub-samples of the dataset. A database of subfossil pollen assemblages for northern central Siberia (north of 60°C) was used as a training data set for model construction, containing 174 pollen assemblages, climatic characteristics for the sampling area, and calculations of forest cover based on remote sensing data. Leave-one-out cross validation was appy for testing of the methods. The results showed that all models had the highest coefficients of determination (R2), the smallest errors and the lowest uncertainty for the reconstruction of the mean July temperature. The developed methods were applied to two key sites in Central Siberia, located in the vicinity of Igarka and the settlement of Tura (Krasnoyarsk Region). The results obtained showed similar trends in the changes in palaeoclimatic characteristics reconstructed by different methods, but a rather large variation in temperature and precipitation values at some time intervals.

Influence of feed mixtures on the productivity of cows and chemical composition of milk during the period of increasing the milk yield

There is a wide variety of climatic zones in the huge territories of our country, which require special approaches to feeding and housing of animals. Providing animals with adequate and rationed feeding under the conditions of the Northern Trans-Urals and Siberia is a difficult task due to the long stall period. The purpose of the work was to determine the infl uence of diff erent methods of feed distribution such as separate and feed mixture on milk productivity of cows and the chemical composition of milk during the period of increasing the milk yield. It was found that the milk yield of natural fat content during the fi rst 100 days of lactation in the experimental group of cows was 325 kg or 10,21 % higher than in the control group. Milk fat yield was obtained from the cows of the experimental group by 16,5 kg or 13,80 % more compared to the animals of the control group. The mass fraction of fat in the milk of cows in the experimental group was higher by 0,12 abs.%. However, the difference between groups in milk yield, milk fat content and milk fat yield was statistically insignificant. The difference in the content of protein, ash, calcium and phosphorus in the milk of the experimental animals was also insignificant, although there was some advantage in the content of these indicators in the experimental group, where the feed was fed in the form of the feed mixture. It was found when analyzing economic indicators that for cows in the control group the prime-cost of 1 kg of milk was 16,49 rubles, which was by 1,53 rubles or 3,91 % more than in the experimental group. At the same time, the level of profitability of milk production in the experimental group was higher than 12,66 abs.% compared to the control group.

Assembling the Proto-Yangtze Block in the late Paleoproterozoic: Constraints from a refined Magmatic-Metamorphic framework of the Cuoke Complex, SW China

The Archean-Paleoproterozoic records of the southwestern and northern Yangtze are key components in establishing the early history of the Yangtze Block as a whole. To date, knowledge of the late Paleoproterozoic evolutionary history of the Yangtze Block has been largely derived from its northern margin. This study documents the presence of ca. 1.93 Ga metamorphic zircons and 1.89–1.86 Ga metamorphic-hydrothermal reset zircons from igneous rocks in the Cuoke Complex of southwestern Yangtze, as well as ca. 1.93 Ga and 1.86 Ga xenotime growths in a meta-volcaniclastic rock (tuff). In addition, the origin of 2.0–1.85 Ga zircons from magmatic rocks in both the Cuoke and Phan Si Pan complexes of the southwestern Yangtze Block are reassessed. Based on new and published CL images, U contents and REE patterns, we argue that the 2.0–1.85 Ga ages are reset from primary 2.3 Ga magmatic zircons during a widespread metamorphic-hydrothermal overprinting event. Integrated U-Pb data reveal two metamorphic peaks at 2.0–1.95 Ga and ca. 1.85 Ga in both northern and southwestern Yangtze, indicating the two domains came together at 2.0–1.95 Ga to form the proto-Yangtze Block. The geological records of northern and southwestern Yangtze match well with those of northern Laurentia and Siberia, respectively, suggesting an internal location for the proto-Yangtze Block within Nuna. This contrasts with its inferred external location within the Rodinia supercontinent, suggesting the transition between the two Proterozoic supercontinents involved significant reconfiguration of at least some of the constituent core continental blocks.

Discovery of the rove beetle subfamily Trichophyinae (Coleoptera: Staphylinidae) in Upper Cretaceous Taimyr amber, Siberia, Russia

The monogeneric rove beetle subfamily Trichophyinae (genus Trichophya) is reported from Upper Cretaceous Taimyr amber from Yantardakh in northern Siberia. The Taimyr specimen of Trichophya is assigned to the “pilicornis species-group” which contains the majority of extant species. It is differentiated from the single known trichophyine fossil Trichophya minor Yamamoto and Newton, 2021 from ca. 99 Ma mid-Cretaceous Myanmar amber, which is placed in the “antennalis species-group” together with one recent species. Together with Trichophya minor, our newly discovered fossil Trichophya species demonstrates that the two morphologically different recent Trichophya species groups were already present far back in time. The taxonomy, biogeography and paleoecology of the Taimyr amber Trichophya is placed in the context of the known morphology, distribution and habitat requirements of the extant species.

Combined effects of temperature, photoperiod, and salinity on reproduction of the brine shrimp Artemia sinica (Crustacea: Anostraca).

Artemia sinica is a brine shrimp species distributed in hypersaline salt lakes in northern China and Siberia and a successful invasive species in some coastal salterns. Although it is a commercially harvested and cultured species, knowledge of its reproductive characteristics is limited, and existing studies are often contradictory. The combined effects of temperature, salinity, and photoperiod on reproduction characteristics are experimentally studied to better understand its reproductive features. There were 36 combinations of three environmental factors (3×3×4), each with three or four levels, namely temperature (16, 25, 30°C), photoperiod (6 L:18 D, 12 L:12D, 18 L:6D), and salinity (50, 100, 150, 200 PSU). In each treatment, 48 to 80 pairs of A. sinica from Yuncheng Salt Lake (Shanxi, China) were cultured. Females were observed daily for reproductive mode and the number of offspring produced. Temperature, photoperiod, salinity, and their interactions significantly affected the lifespan and reproduction of A. sinica. The reproductive period was the longest and accounted for the largest proportion of life span at moderate temperature (25°C). Total offspring, offspring per brood, and offspring per day increased as salinity decreased, and the number of broods per female was highest at 25°C. Temperature, photoperiod, and salinity significantly influenced reproductive modes, and interactions among these factors were identified. Artemia sinica primarily reproduces oviparously under low temperature and short daylight conditions, and ovoviviparously under high temperature and long daylight conditions, with the maximum oviparity ratio recorded in treatments of 16°C, 6L:18D, and 50 or 100 PSU. The maximum ovoviviparity ratio was recorded under 30°C, 12L:12D, and 100 PSU. Unlike that documented for other Artemia species or populations, the brood size of A. sinica kept increasing throughout the reproductive period. It did not decline even in the last two broods. For the same brood number, the sizes of oviparous and ovoviviparous broods were similar. The length of the oviparous interval was often greater than that of the ovoviviparous interval, suggesting that oviparous offspring might require additional energy and time to construct the multi-layered eggshell. Compared to other species and populations, the A.sinica from Yuncheng Salt Lake has a relatively shorter pre-reproductive development time, a preference for ovoviviparity, and relatively higher fecundity and population growth capacity, making it a suitable culture species for obtaining fresh biomass.

C, O, and Sr Isotope Compositions of Belemnites from the Bajocian–Bathonian of Arctic Siberia: Implications for Global Correlations and Paleogeographic Reconstructions

Abstract —The Middle Jurassic sedimentary strata of Siberia remain poorly studied chemostratigraphically. We contribute to the knowledge with pioneering C, O, and Sr isotopic data for carbonate material of belemnites from the Yuryung-Tumus Peninsula and the lower reaches of the Lena River, as a basis for comprehensive description of the north Siberian Bajocian and lower Bathonian. The obtained chemostratigraphic constraints, with new 87Sr/86Sr ratios and previous δ13C and δ18O estimates, also include data for the lower Bathonian in the Sokur section (Central Russia). Despite the limited amount of material, chemostratigraphy, along with the available biostratigraphic data, allows reliable correlation of the Boreal sections with the primary standard of Northwest Europe, which is impossible for these strata with any of the two methods alone. The δ13C, δ18О, and 87Sr/86Sr patterns correlate with the records of eustatic, climatic, tectonic, and paleogeographic events. The new δ18O data and the inferred paleotemperatures for the latest early Bajocian and the Bajocian/Bathonian boundary reveal two excursions of notable seawater warming near the Siberian Arctic coast, which were synchronous with episodes of global sealevel rise. It was presumably during the eustatic events that the N–S Komi Strait (first naming) opened twice in the territory of the Russian Plate. The strait connected the Boreal and Tethyan seas and thus changed the oceanic circulation patterns. Specifically, it opened a gateway for a warm current from the south to northern Siberia responsible for the high seawater temperatures recorded in the δ18О patterns of belemnites.

Phenolic Compounds of Rhodiola rosea L. as the Potential Alternative Therapy in the Treatment of Chronic Diseases.

The roots and rhizomes of Rhodiola rosea L. (Crassulaceae), which is widely growing in Northern Europe, North America, and Siberia, have been used since ancient times to alleviate stress, fatigue, and mental and physical disorders. Phenolic compounds: phenylpropanoids rosavin, rosarin, and rosin, tyrosol glucoside salidroside, and tyrosol, are responsible for the biological action of R. rosea, exerting antioxidant, immunomodulatory, anti-aging, anti-fatigue activities. R. rosea extract formulations are used as alternative remedies to enhance mental and cognitive functions and protect the central nervous system and heart during stress. Recent studies indicate that R. rosea may be used to treat diabetes, cancer, and a variety of cardiovascular and neurological disorders such as Alzheimer's and Parkinson's diseases. This paper reviews the beneficial effects of the extract of R. rosea, its key active components, and their possible use in the treatment of chronic diseases. R. rosea represents an excellent natural remedy to address situations involving decreased performance, such as fatigue and a sense of weakness, particularly in the context of chronic diseases. Given the significance of mitochondria in cellular energy metabolism and their vulnerability to reactive oxygen species, future research should prioritize investigating the potential effects of R. rosea main bioactive phenolic compounds on mitochondria, thus targeting cellular energy supply and countering oxidative stress-related effects.

The Ammonite Catacadoceras barnstoni Beds and the Problem of the Separation of the Middle and Upper Substages of the Bathonian Stage in Northern Siberia

The Ammonite Catacadoceras barnstoni Beds and the Problem of the Separation of the Middle and Upper Substages of the Bathonian Stage in Northern Siberia

Paleometagenomics reveals environmental microbiome response to vegetation changes in northern Siberia over the millennia

AbstractThe study of environmental ancient DNA provides us with the unique opportunity to link environmental with ecosystem change over a millennial timescale. Paleorecords such as lake sediments contain genetic pools of past living organisms that are a valuable source of information to reconstruct how ecosystems were and how they changed in response to climate in the past. Here, we report on paleometagenomics of a sedimentary record in northern Siberia covering the past 6700 years. We integrated taxonomic with functional gene analysis, which enabled to shed light not only on community compositions but also on eco‐physiological adaptations and ecosystem functioning. We reconstructed the presence of an open boreal forest 6700 years ago that over time was gradually replaced by tundra. This vegetation change had major consequences on the environmental microbiome, primarily enriching bacterial and archaeal ammonia oxidizers (e.g., Nitrospira, Nitrosopumilus, and Ca. Nitrosocosmicus) in the tundra ecosystem. We identified a core microbiome conserved through time and largely consisting of heterotrophic bacteria of the Bacteroidetes phylum (e.g., Mucilaginibacter) harboring numerous functional genes for degradation of plant‐biomass and abiotic and biotic stress resistance. Archaea were also a key functional guild, involved in nitrogen and carbon cycling, not only methanogenesis but possibly also degradation of plant material via enzymes such as cellulases and amylases. Overall, the paleo‐perspective offered by our study can have a profound impact on modern climate change biology, by helping to explain and predict the ecological interplay among multiple ecosystem levels based on past experiences.

The Ammonite Catacadoceras Barnstoni Beds and the Problem of Separation of the Middle and Upper Substages of the Bathonian Stage in Northern Siberia

The paper presents the results of studying the taxonomic composition of ammonites of the family Cardioceratidae in the Bathonian of northern Siberia in the range of distribution of the last representatives of the genus Arcticoceras and the first representatives of the genus Catacadoceras to solve the problem of distinguishing between the Middle and Upper Bathonian. The incorrectness of all previous identifications of the Middle Bathonian species Arcticoceras cranocephaloide Callomon et Birkelund, 1985 based on the northern Siberian material has been established. These determinations were mainly based on Late Bathonian ammonites belonging to the species Catacadoceras barnstoni (Meek, 1859) or the form characterized by a narrow umbilicus and described herein as Cat. aff. barnstoni. An updated zonal scale of the Middle–Upper Bathonian of Siberia based on ammonites is proposed, which is recommended for use both in the regional stratigraphic schemes of the Jurassic deposits of Eastern (Middle) Siberia and in the Boreal (Siberian) zonal standard of the Bathonian Stage. The extreme importance of preserving an auxiliary biostratigraphic subdivision in this scale, the Cat. barnstoni Beds, is noted, which is due to the wide distribution and abundance of the index species in Siberian sections, as well as its significance for the correlation of the lower part of the Upper Bathonian of northern Canada, northern Siberia, Franz Josef Land and East Greenland. In addition, two intervals, namely interval with Cat. aff. barnstoni and interval with Cat. perrarum, are fixed as benchmarks, which are useful for the rapid age estimation and correlation of the Upper Bathonian deposits in Arctic sections within the upper part of the Cat. barnstoni Beds.

Direct atmospheric cryogenic carbon capture in cold climates

Fossil fuel burning and land clearing have significantly increased atmospheric carbon dioxide (CO2) levels from a preindustrial concentration of about 280 ppm to over 420 ppm, leading to a rise in global temperatures and ocean acidity. Although there exist both natural ways to capture carbon, such as trees, oceans, and wetlands, and engineered approaches, such as capturing CO2 at the source of flue gas, even under extremely optimistic scenarios, additional methods to capture carbon directly from the atmosphere are needed. This account provides a critical examination of the concept, as well as a review of pioneering early-stage research pertaining to cryogenic CO2 capture plants designed for deployment in extremely cold environments, such as northern Canada, Siberia, or Antarctica. Based on theoretical analysis, such a plant could desublimate CO2 at an energy cost of around 30 GJ/tonne CO2, which is about an order of magnitude higher than chemical-based approaches. With further research and technological advancements, the cryogenic direct-air capture (DAC) of CO2 could potentially become economically feasible.

Clay mineral and Nd, Pb, and Sr isotope provenance of a MIS 4-3 sediment record from the Lomonosov Ridge, central Arctic Ocean

Modern techniques for detrital mineral provenance were applied to sediment core 96/12-1pc from the Lomonosov Ridge in the central Arctic Ocean. The techniques include quantitative clay mineralogy analysis combined with determination of Nd, Pb, and Sr isotopes from clay fraction. The clay mineral assemblage and the isotope signatures depict distinct changes during the Marine Isotope Stage (MIS) 4-3 transition corresponding to the Middle Weichselian deglaciation. This transition is characterised by a homogenous, 48 cm thick, dark grey, silty clay layer with a distinctive IRD concentration, forming a prominent marker bed for the central Arctic Ocean sediments. The elevated smectite and kaolinite contents in the transitional interval are possible weathering products of the Siberian basaltic rocks, such as the Putorana Plateau, feeding the shelves of the Kara Sea and the western Laptev Sea. The Nd and Sr isotope values are compatible with input from the basaltic rocks and fall within the isotopic range of sediments from these shelves. The abrupt changes in the Nd, Pb and Sr isotopic data from the distinct grey layer attributed to the MIS 4-3 transition likely mark a pronounced deglaciation event. An increase in coarse debris in the grey layer indicates a change in the sedimentation regime with a strong iceberg rafting component. This change may also be related to a sudden release of meltwater from a large ice-dammed lake in the northern Siberia.