The present work reports on new mineralogical and whole-rock geochemical data from the Breivikbotn silicocarbonatite (Seiland igneous province, North Norway), allowing conclusions to be drawn concerning its origin and the role of late fluid alteration. The rock shows a rare mineral association: calcite + pyroxene + amphibole + zeolite group minerals + garnet + titanite, with apatite, allanite, magnetite and zircon as minor and accessory minerals, and it is classified as silicocarbonatite. Calcite, titanite and pyroxene (Di36–46 Acm22–37 Hd14–21) are primarily magmatic minerals. Amphibole of mainly hastingsitic composition has formed after pyroxene at a late-magmatic stage. Zeolite group minerals (natrolite, gonnardite, Sr-rich thomsonite-(Ca)) were formed during hydrothermal alteration of primary nepheline by fluids/solutions with high Si-Al-Ca activities. Poikilitic garnet (Ti-bearing andradite) has inclusions of all primary minerals, amphibole and zeolites, and presumably crystallized metasomatically during a late metamorphic event (Caledonian orogeny). Whole-rock chemical compositions of the silicocarbonatite differs from the global average of calciocarbonatites by elevated silica, aluminium, sodium and iron, but show comparable contents of trace elements (REE, Sr, Ba). Trace element distributions and abundances indicate within-plate tectonic setting of the carbonatite. The spatial proximity of carbonatite and alkaline ultramafic rock (melteigite), the presence of “primary nepheline” in carbonatite together with the trace element distributions indicate that the carbonatite was derived by crystal fractionation of a parental carbonated foidite magma. The main prerequisites for the extensive formation of zeolite group minerals in silicocarbonatite are revealed.
In the current paper, the methods of calculating infiltration for different ways of the ventilation system operation have been reviewed. The calculation of infiltration losses of buildings in cases of organizing natural and mechanical supply and exhaust ventilation, as well as recent scientific research in this area, has been considered. The calculation of natural ventilation with the values of air exchange given in Set of Rules 54.13330.2016 “Residential multi-apartment buildings” has been compared with the calculation of mechanical ventilation taking into account different glazing of the building facade. The influence of gravitational and wind components of pressure on various facades of the building has been analyzed. The gravitational and wind effects on the building are illustrated as a pressure diagram. The calculation of the specific heat flux for heating the infiltrated outdoor air on each floor is presented. The scientific studies of infiltration losses with a mechanical balanced supply and exhaust ventilation system proposed by A.S. Kubenin in his scientific work have been considered. The method of calculating the amount of infiltrated air for residential and public buildings has been thoroughly researched. Studies of heat consumption for one or more windward facades are presented. Criteria conditions of different schemes of filtration air exchange at different wind directions are formulated.
The present work reports new mineralogical and whole rock geochemical data from the Breivikbotn silicocarbonatite (Seiland igneous province, North Norway), allowing conclusions to be drawn concerning its origin and the role of late fluid alteration. The rock shows a rare mineral association: calcite + pyroxene + amphibole + zeolite group minerals + garnet + titanite, with apatite, allanite, magnetite and zircon as minor and accessory minerals, and it is classified as silicocarbonatite. Calcite, titanite and pyroxene (Di36-46 Acm22-37 Hd14-21) are primarily magmatic minerals. Amphibole of hastingsitic composition has formed after pyroxene at a late-magmatic stage. Zeolite group minerals (natrolite, gonnardite, Sr-rich thomsonite-(Ca)) were formed during hydrothermal alteration of primary nepheline by fluids/solutions with high Si-Al-Ca activities. Poikilitic garnet (Ti-bearing andradite) has inclusions of all primary minerals, amphibole and zeolites, and presumably crystallized metasomatically during a late metamorphic event (Caledonian orogeny). Whole rock chemical compositions of the silicocarbonatite differs from the global average of calciocarbonatites by elevated silica, aluminium, sodium and iron, but show comparable contents of trace elements (REE, Sr, Ba). Trace element distributions indicate within-plate tectonic setting of the carbonatite. The spatial proximity of carbonatite and alkaline ultramafic rock (melteigite), the presence of “primary nepheline” in carbonatite together with the trace element distributions indicate that the carbonatite was derived from crystal fractionation of a parental carbonated foidite magma. The main prerequisites for the extensive formation of zeolite group minerals in silicocarbonatite are revealed.
This work summarizes literary and cartographic material that characterizes the Morskoy Glaz Lake and its catchment area. The levels of aquifers and the catchment area of the lake were determined along with development of digital models of the terrain and relief of the lake basin, which were developed on the basis of multi-temporal microdrone photo-shooting with usage of geodetic referencing of basepoints using the tools of Agisoft Metashape and GIS “Panorama”. The catchment area of the lake doesn’t exceed more than 1.3 km², while the main supply of water nourishment of the lake forms as a surface runoff and groundwater flow on an area of about 0.6 km². This area contains 45 residential building connected by local sewerage and many private water wells. The lands of rural settlements and agricultural lands make up 26 % and 64 % of main catchment area, respectively. With the usage of photographic materials of the lake provided by users of social medias and usage of digital terrain models of Agisoft Metashape, a reconstruction of the dynamics of the lake water levels for 2013–2022 was carried out, which made it possible to calculate volumes of lake waters for specific calendar dates along with possibility of estimation of the rate of change of water volumes in the lake, which was achieved through the usage of tools of GIS “Panorama”. Long-term level of water’s edge of the lake is 121.5 meters, the total volume of the lake is 53,185 m³. Since 2014, there have been significant fluctuations in the level of the water’s edge in the lake. Meanwhile, the rate of water volume change varied from 3.9 to −3.6 dm³ per second. The reason for the negative water balance in March 2022 is formation of a ponor at the end of the winter of 2014, which subsequent expansion along with periodic overlapping by screes and microlandslides have led to complete disappearance of the lake. The proposed algorithm based on the usage of the Citizen science technologies (collection of amateur photo- and video- data), combined with usage of GIS-tools can be used for providing monitoring for water bodies.
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