This article is about the XIV All-Russian open field Olympiad for young geologists. Subject Olympiads are a competition of students where participants demonstrate their skills and knowledge in certain disciplines. The children's and youth geological movement in Russia has a very rich history. Today, in the country, the promotion of geological knowledge among schoolchildren is carried out in accordance with the training program, innovative programs introduced as part of the implementation of the priority national project "Education". The All-Russian fields Olympiads for young geologists are held by the Federal Agency for Subsoil Use in different regions of Russia every two years. The organizers of the Olympiad hope that thanks to the movement of young geologists, a new generation of highly professional specialists will grow up. The novelty of the article is the description of the participation in 2023 of a team of schoolchildren from Yakutia in the XIV All-Russian Field Olympiad in Geology in Tatarstan. The experience of the Yakut team Kimberlit should help the next participants of the Olympiad from the republic. Competitions and contests of the Olympiad are original, require non-standard thinking and flexibility of mind. However, many of the tasks of the Olympiad are composed by analogy with previous years. Therefore, an effective way to prepare is to know the specifics of the tasks of the Olympiads of previous years. Observation of the Kimberlite team during the competition allows us to state that the Geology Olympiad provides not only knowledge and skills, but also the experience of human communication, physical training, and everything that is necessary for a real geologist. Participation in the Olympiad is a great responsibility, especially for a representative of a subject of the federation.

The article presents the results of a microprobe study of the composition of phlogopite macrocrystals with inclusions of chrome spinelides from An-195 kimberlite body of the West Ukukit field; Yakut kimberlite province. The purpose of this study was to establish the genesis of such phlogopites: whether they are representatives of deep mantle matter or their formation is directly related to the formation of kimberlites composing An-195. It was found that the inclusions of chrome spinelides are confined only to chromic non–zonal phlogopites or to chromic sites of zonal macrocrystals (Cr₂O₃ 0.75–1.55 wt.%; TiO₂ 2.67-3.84 wt.%; Mg# 83-88). Based on a comparative analysis of the studied phlogopites and chromespinelides with the composition of analogues from the parageneses of these minerals in various mantle xenoliths of ultrabasic rocks; eclogites and rocks of the MARID series; it was concluded that these phlogopites most likely represent a phenocrystal association of kimberlite minerals. They clearly differ from phlogopites of the MARID series rocks with equal Mg# and TiO₂ in higher Al₂O₃ contents; from phlogopites of ultrabasic mantle rocks xenoliths – generally with lower magnesia content. Phlogopites from eclogites have a generally higher Cr₂O₃ content. Inclusions of high–chromium spinelides in phlogopite (Cr₂O₃ 44-50 wt.%; TiO₂ 3-5.5 wt.%; Fe³⁺ < 0.35 f.e.) correspond in composition to spinelides from cataclysmic dunites and are products of their recrystallization under the influence of high-temperature mantle fluid. Inclusions of less chromic spinelides (Cr₂O₃ 30-44 wt.%; TiO₂ 4-7.5 wt.%; Fe³⁺ > 0.35 fe) probably crystallized simultaneously with phlogopite macrocrystals and were captured by them during long-term co-growth.

As a result of the research; a conclusion was made about the high prospects for the growth of gas reserves of Andylakhskoye gas condensate field- located within the Loglor swell of the Vilyui syneclise of the Sakha Republic (Yakutia). An increase in reserves is expected; both due to previously discovered deposits and new; more promising horizons located in the Permian deposits.

It is proposed to set up seismic surveys using the 2D common depth point method within the field and the adjacent; most promising areas to increase investment attractiveness; the rational use of natural resources; and increasing gas reserves of Andylakhskoe gas condensate field. According to the results of the studies carried out in this article; the prospects for the growth of hydrocarbon reserves of Andylakhskoe gas condensate field are estimated by over 10 times of the amount.

The paper deals with the issue of regional gas content of Nejelinsky formation of the Lower Triassic. Based on the consideration of the peculiarities of the gas content of Nejelinsky formation and the upper productive horizons of the Permian age within the Khapchagai megawall; it is concluded that there are two types of deposits in the section of Nejelinsky formation. The first type of deposits is gas-hydrodynamically limited in the volume of Nejelinsky formation and is genetically related to breakthrough gases from the Permian part of the section. The second type of deposits is gas-hydrodynamically related to deposits in the upper part of the Permian productive horizon. Due to the lack of its own gas formation potential in Nejelinsky formation outside the Khapchagai and Loglorsky shafts; it can only be considered as an effective fluid barrier. It is concluded that in the absence of isolated deposits in Nejelinsky formation; favorable reservoir properties in the Permian part of the section should be expected.

In the modern world; geology is one of the most important scientific disciplines that can provide key knowledge about the structure and processes of our planet. Applied geology; in particular; requires high qualifications and practical experience; and field training geological practices play a key role in the formation of not only theoretical knowledge of students but also of their practical skills. Educational geological practices permit students of the Faculty of Geology and Survey; North-Eastern Federal University; to master basic methods in field geological research; including the analysis of rock formations; the identification of geological boundaries; and the recognizing of relief-faults.

This article provides an overview of the structure and specifics of field training geological practices; involving multiple stages from preparatory to fieldwork period. The article considers not only essence and significance of field research in terms of formation practical geological skills but also analyze the key aspects that make these practices an integral part of the education of future geologists.

The article considers the features of the petrographic composition of the lamprophyre dyke; attributed to the kHunkhadi complex of Late Cretaceous age; established on the Endegechchu hill in the Yano-Adycha tin ore region located in the Adycha tectonic zone. The rocks have a porphyry structure; and mineral formations of their own magmatic stage; magmatic; metasomatic and late hydrothermal-metasomatic substitutions are isolated in their composition. A characteristic feature of these rocks are spherulites of concentric-zonal structure; covered with a shell of scaly or lamellar graphite; depending on the size of the spherulites; evenly distributed throughout the rock; which were studied for the first time and have not been established in other igneous rocks widely developed in the area. The study of spherulites is an important petrological task; which makes it possible to identify the mechanisms of their formation and causes; can indicate the conditions of formation and sources of matter of the rocks containing them. The morphology of graphite; its distribution and the nature of its relationship with surrounding minerals are also very informative for establishing the primary nature of graphite and epigenetic changes in host rocks as a result of various hydrothermal-metasomatic processes; which is possible due to the ability of carbonaceous matter to redistribute in the rock when exposed to various forces; rather than being removed from it. 

In landscape and biogeographic studies, the assessment of the photosynthesis process, which affects the possibility of determining the productivity of phytocenoses, calculating the growth of phytomass, is of particular relevance. The use of unmanned aerial vehicles (UAVs) to evaluate the leaf surface index (LAI) is gaining more and more scope over time due to their low price, high operational efficiency and accuracy. The basis for determining LAI is a model for the slit fraction, theoretically estimated using the Bera-Booger-Lambert law. The possibility of determining the LAI of vegetation using a UAV, on board of which either a lidar or a multispectrometer can be installed, is analyzed. In the first problem, LAI is determined by calculating the logarithm of the slit function (fraction) multiplied by the cosine of the scanning angle and divided by the attenuation coefficient. The second problem uses the existing correlations between known vegetation indices and LAI. Empirical statistical regression models may be suitable for determining LAI after determining various vegetation indices. Based on the results of multispectral measurements, it was found that the LAI determination technique based on measuring the intensity of rays that passed through the crown of plants leads to highly noisy estimates. For this reason, it was decided to use the slit fraction (GF), while using the experimentally established fact that when multiplying the logarithm of the vegetation index by the height of the crown, this correlation is significantly enhanced. To increase the reliability of the obtained LAI values, it is proposed to use the average integral value of this indicator, calculated by composing and calculating an optimization variational problem containing an additional restrictive condition. At the same time, it is possible to solve both problems to the maximum, i.e. it becomes possible to increase the signal-to-noise ratio of the calculated value of the LAI index. In both optimization calculation procedures, there are generalized indicators that have different physical meanings.

Presently, the climate is warming, with average annual temperatures rising every year, and the Arctic remaining one of the most vulnerable regions. This has a noticeable effect on the northern forests, which leads to the displacement of the tundra zone. Assessing the consequences of a projected increase in air temperature under climate change conditions requires spatial and instant monitoring of hard-to-reach areas. In the last few years, the use of remote sensing techniques and combinations of satellite imagery to calculate vegetation indices has generated great interest in obtaining high-definition ground data. The article presents the results of modeling soil moisture in Anabar tundra, which is located in the north-west of Yakutia.  The study was conducted on the border of tundra and forest tundra in three reference areas (tundra, tundra young forest, tundra indigenous forest). The simulation is presented by comparing the field data and the normalized difference index of humidity NDMI. The NDMI index uses the NIR and SWIR channels, calculates a multi-channel raster object and creates a raster image with index values from -1 to 1, which show the humidity level with a spatial resolution of 10 meters. The data showed that the value of humidity pixels according to NDMI in the tundra zone is 0.04, in the tundra young forest is 0.09 and, in the tundra, native forest is 0.15. It was found that the index data correlated with field humidity data obtained from a depth of 0.2 m. A comparison of remote sensing decryption data with field data made it possible to simulate the spatial distribution of soil moisture over the vast study area by extrapolation.

Investigations over the last decades have shown that Yakutia is not only a highly representative area for the study of global climate patterns, it is a model of the Earth due to the extensive influence of the Siberian anticyclone. Covering a grid of coordinates from the Arctic and Pacific Oceans almost to the Atlantic and Tibet, Yakutia dictates the patterns of climate change for the entire Northern Hemisphere. That can be clearly seen on example of modern climate change. The rate of warming here outpaces the rate of the Earth warming in 3-5 average annual degrees, thus showing not only the current warming trend, but also predicting it for the entire Earth with further temperature rise in future. Our paper shows the course of climate change over the last three centuries.  It relies on the global patterns of atmospheric circulation on the wave of the hundred-year rhythm. Their essence is that the middle of centuries always brings cooling associated with latitudinal circulation of the atmosphere, and the turn of the century – the warming, in which latitudinal circulation is replaced by meridian circulation. It was happening in the last three centuries, confirmed by instrumental observations, and so it was in the time of Columbus and Vikings. Both came to America at the turn of the century 500 and 1000 years ago, when the Arctic Ocean and the North Atlantic were ice-free.

For the purposes of monitoring the state of forest ecosystems, it is most effective to use the capabilities of remote methods. On multispectral Landsat satellite images (a time series of summer and autumn images for 2000, 2001, 2013, 2014) of the territory of the Olekminsky State Nature Reserve, fragments of forests dominated by Gmelin larch (Larix gmelinii Rupr.) with an area of 250 km² (scale 1:5000). Then the polygons were saved at three levels of segmentation (scaling) – 4, 16, 64 with scales of 1:2500, 1:1250, 1:625. During decryption, uncontrolled classification of polygons using the ISODATA (Iterative Self-Organizing Data Analysis Technigue) method into 2,4,10 classes was carried out. Classification into two classes was used to calculate the forest cover index. Seasonal changes were determined by the difference in the forest cover index values of the polygons in summer and autumn. It has been shown that the greater the difference, the greater the proportion of larch in mixed forest stands. Distribution curves of forest cover index values were constructed for polygons of the 3rd scaling level. Based on the results of classification into 4, 10 classes, statistical processing was carried out with the calculation of indicators of difference and similarity of polygons - dispersion of the general population and Fisher's test (F-test). The results of changes in population dispersion and F-test at different levels of segmentation and in different years are considered.

The accuracy of GHCN-CAMS reanalysis reproduction of the intra-annual air temperature distribution was assessed for the historical (1961-1990) and current (1991-2020) climatic periods, on the scale of climatic norms of seasons and individual months. Data on 86 meteorological stations on the territory of the Sakha Republic (Yakutia), for which climatic series in both time periods were available, were used. The climatic norms of meteorological stations for both periods, as well as their change between periods, were compared with the GHCN-CAMS reanalysis data in corresponding pixels. The root mean square error, Pearson correlation coefficient, and Lin's concordance coefficient were calculated as similarity metrics. Climatic norms for meteorological stations and calculated in the GHCN-CAMS reanalysis model are closely related linearly, with a correlation coefficient above 0.9, and the highest accuracy is observed for spring months. At the same time, the quality of reanalysis reconstruction of change in climatic norms for months and seasons between periods is significantly lower; the best reanalysis accuracy is for fall and winter, and significantly lower for summer. In general, the GHCN-CAMS model can be used for calculation and forecasting applications that require intra-annual air temperature distribution.

A spatial analysis of intra-regional transport accessibility of settlements in the Arctic districts of the Sakha Republic (Yakutia) by GIS is an urgent task and can become a necessary support for the processes of decision-making and planning of sustainable development of these territories. The purpose of the study is to perform a spatial analysis of intra– regional transport accessibility of settlements in remote Arctic regions of Yakutia on the example of Anabarsky and Nizhnekolymsky districts. On the basis of the GIS network analysis and calculated coefficients of density of the transport network, the assessment of transport accessibility of the study areas according to winter and summer scenarios was carried out. The automobile and river networks were built on the basis of data from open cartographic sources: OpenStreetMaps and Google Earth Engine, the atlas of highways of the Sakha Republic (Yakutia). On the basis of satellite images of Landsat 5, 8 and Sentinel 2, non-official (informal) roads that play an important role in communications between settlements were decrypted and digitized. QGIS and ArcGIS programs were used to perform network analysis and build a map of time availability of the settlements using isochronous method. The created maps clearly show the availability of settlements by time interval. The conducted research made it possible to determine that remote sensing and geoinformation systems are key tools for a spatial analysis of transport infrastructure. Using this tools, it is possible to conduct network analysis of various levels of complexity, as well as build graphs of the transport network, greatly simplifying the counting procedure. The paper tested a method that allows to identify unofficial roads in the Arctic, and the presented methods of GIS analysis and modeling that can be used for further deeper network analytics and graph theory to improve the methodology for studying the transport accessibility of the Republic of Sakha (Yakutia).