Specific features of sandstones of Upper Devonian Tayokuyakhinskaya Formation on southeastern slope of the Kanin Kamen range (Kanin Peninsula)

The results of studying the lithological and geochemical characteristics of sandstones of the Upper Devonian Tayaokuyakhinskaya Formation in the southeastern part of the Kanin Nos Peninsula are presented. The accumulation of sandstones of the Tayaokuyakhinskaya Formation occurred in the absence of volcanic activity in a shallow basin with small periodic fluctuations in sea level, which led to a change in the degree of maturity, sorting, and the ratio of clay and sandy components in the rock. The accumulation of the psammitic strata occurred due to the destruction and redeposition of weakly weathered sedimentary rocks in a moderately warm climate. It was established that the formation of the composition of sandstones was influenced by at least two sources of clastic material — garnet-bearing crystalline shales and feldspar-quartz sandstones metamorphosed into the greenschist facies. The latter, most likely, were the source of the indicative gold contents found in the Devonian clastic rocks.

Geochemical characteristics of the Late Devonian basaltoids of the Kanin Peninsula and the Middle Timan

The petrochemistry and geochemistry of dolerites and basalts of the Late Devonian Kanin-Timan complex of the Kanin Peninsula and the Middle Timan are considered. Petrochemically, the rocks of the Kanin-Timan complex of the Kanin Peninsula and the Tsilma river area of the Middle Timan correspond to basaltoids of the normal range of alkalinity and partially to moderately alkaline varieties, and belong to the tholeiitic series. The least differentiated varieties are dolerites of the southeastern Kanin Peninsula, the most differentiated are the basalts of the river Tsilma of the Middle Timan. The lowest REE concentrations were found in the rocks of the central part of the Kanin Peninsula (36.5-56.8 g/t); in the same samples, the lowest LaN/YbN values were recorded (1.85 and 2.4, respectively), which indicates an increased degree of melting of the source. The highest REE concentrations were found in basalts from the river Tsilma (77.13-88.33 g/t), LaN/YbN values (2.49-2.7, respectively). The influence of the crustal component in the formation of melts from which rocks of the Kanin-Timan complex were formed, was established. The source of the melt was spinel-garnet lherzolite, the degree of melting varied from 10 to 30%. The maximum degree of melting was 30%, at which melts were formed, that gave rise to the least differentiated rocks of the Northern Timan and the central part of the Kanin Peninsula. The mantle source, that gave rise to the melts from which the rocks of the Kanin-Timan complex were formed, was enriched with subduction and crustal components, a similar type of source is characteristic of the basaltoids of the No-rilsk trough.

Soil invertebrates occurrences in European North-East of Russia

The European North-East of Russia is the territory which includes the Nenets Autonomous District, represented by the East European tundra (from Kanin Peninsula to Vaigach Island), Komi Republic with its taiga ecosystems and the Urals (Northern, SubPolar and Polar). Over 20 years of systematic studies of soil fauna in the studied region has resulted in a huge amount of data being accumulated that can be analysed from different positions. Considering that the representation of Russian soil biota data, especially from European North-East of Russia in the GBIF database is not large, our data are of great interest to the scientific world community. The accumulation of such data will solve questions on national and global scales using large arrays. This study produced a dataset containing information on occurrences on soil invertebrates (Lumbricidae, Chilopoda, Diplopda, Collembola, Elateridae and Staphylinidae) in the European North-East of Russia. The dataset summarises occurrences noted in natural and disturbed forests, tundra and mountain ecosystems. Data from 196 geo-referenced localities of European North-East of Russia (tundra, taiga and mountains ecosystems) have been collated. A total of 5412 occurrences are included in the resource. The current project surveys 13 species of earthworms, 20 species of millipedes, 246 species of springtails, 446 species of rove beetles and 60 species of click beetles. The diversity of soil invertebrates in the European North-East of Russia has not been fully explored and further exploration will lead to more taxa.

Coastal vegetation of the river estuaries on the Kanin peninsula

The study of the Kanin Peninsula coastal vegetation started at the beginning of the 20th century (Grigoryev, 1929) and was continued in 1932 by famous researcher A. A. Korchagin who described plant cover in the estuaries of the Nes, Mgla, Vizhas rivers and introduced the first classification of halophytic plant communities of that area (Korchagin, 1935). The data on the analogous vegetation on the shores of the White and Barents seas (in the estuaries of the Chizha, Chesha, and Semzha rivers) were obtained by the first author of this paper in the course of two expeditions: in 2014 (organized with the support of the Russian Geographical Society) and 2017 (Shirshov’s institute of oceanology of the RAS). According to the Braun-Blanquet floristic classification the Prodromus includes 13 associations and 2community types which belong to 7 alliances within 4 orders and 4 classes. Two associations, previously described by A. Korchagin (1935) on marshes in the southern part of the peninsula following the ecological-floristic approach, are validated: Alopecuro arundinacei–Caricetum salinae Korchagin 1935 ex Moseev et Sergienko, Agrostio stramineae–Alopecuretum arundinacei Korchagin 1935 ex Moseev et Sergienko. A new variantof the ass. Puccinellietum phryganodis is described — P. p.var. Tripolium vulgare var.nov. The vegetation on marshes of the studied area is similar with that in the southern part of the Kanin Peninsula (according to the Korchagin’ relevés), as well as on the western coast of the White Sea (associations Agrostio stramineae–Alopecuretum arundinacei, Alopecuro arundinacei–Caricetum salinae, Festucetum rubrae, Plantaginetum maritimae, Salicornietum europaeae, Scirpeto–Hippuridetum tetraphyllae, Triglochino–Caricetum subspathaceae) established by N. V. Babina (2002) and on the southeastern coast of the Barents Sea (Caricetum subspathaceae, Festuco–Caricetum glareosae (syn.: Caricetum glareosae Molenaar, 1974), Scirpeto–Hippuridetum tetraphyllae, Puccinellietum phryganodis (Matveyeva, Lavrinenko, 2011; Lavrinenko, Lavrinenko, 2018). The ass. Caricetum aquatilis is quite common for the lowland mires and lake shores of the taiga zone European part of Russia (Raspopov, 1985; Teteryuk, 2008). There are three geographical groups of syntaxa in the rivers’ estuaries: typical arctic (Caricetum subspathaceae, Puccinellietum phryganodis), hypoarctic (Agrostio stramineae–Alopecuretum arundinacei, Alopecuro arundinacei–Caricetum salinae, Festuco–Caricetum glareosae, Salicornietum europaeae, Scirpeto–Hippuridetum tetraphyllae, Matricario–Leymetum arenarii, Triglochino–Caricetum subspathaceae), and boreal (Caricetum aquatilis, Festucetum rubrae,Plantaginetum maritimae, Triglochinetum maritimi), that reflects the zonal gradient on the Kanin Peninsula from the forest-tundra to the southern and typical tundra subzones. New data expand information on the species composition and structure of salt marsh vegetation of the Arctic seas coasts which can be used in recommendations for maintaining a stable state and protections to oil spills of these the extremely vulnerable communities which are the very important as the reindeer’ pastures and as well as the waterfowl and near-water migratory bird nesting habitats.

VEGETATION DYNAMICS OF MARSHES IN TIDAL ESTUARIES OF THE WAIT SEA AND THE CHESHSKAYA BAY OF THE BARENTS SEA

The article studies the dynamics of overgrowth of saline marches of tidal estuaries of the Whit. Changes in the coastal vegetation depend on the salinity of the water and soil, the magnitude of the tides and the degree of flooding of the coastal strip, the relief and the mechanical composition of the coastal soils. Given the environmental series of overgrowing marches under conditions differing in the magnitude of the tides at the estuary of rivers. It is shown that the halophytic vegetation and its communities occupy the largest areas in the macrotidal conditions of the estuaries of the Chizha and Chesha rivers of the Kanin Peninsula, where marching coast reach 10–20 km from the coastline of the sea at the mouths of rivers. The dynamics of coastal communities depending on water salinity is studied. Communities dominated by obligate halophytes tend to strongly saline ecotopes of marches located on the maritime boundary of estuaries filled with water salinity of more than 20‰, in the zone of constant salinization of estuaries, communities of facultative halophytes and tolerant species more often occupy medium and slightly saline marches in the tops of estuaries.

THE ZIRCON CHRONOLOGY OF THE INTRUSIVE MAGMATISM OF THE KANIN PENINSULA

The Kanin Peninsula is an elevated block of the Timan Ridge where Precambrian sedimentary-metamorphic sequences and magmatic rocks, intruding them, form the Kanin Kamen Ridge. In the northwestern part of the Peninsula on the coast of the Barents Sea, there is a unique outcrop of two-mica granites, monzonitoids and lamprophyres cutting metaterrigenous rocks of the Upper Riphean Tabuyev series and overlain by Lower Permian limestones. To establish the age of magmatic rocks, U-Pb dating of zircons has been carried out by secondary ion mass spectrometry (SIMS) method. In zircons from granites, an age of 883 ± 16 Ma has been obtained, which corresponds to the beginning of the Late Riphean, and the subsynchronous formation of subalkaline rocks occurred in the Late Cambrian. The age of monzogabbro is 505 ± 7 Ma, and lamprophyres – 504±7Ma.