Transportation, turning and installation of the pedestal and column on the Palace Square in St. Petersburg

The materials are devoted to the consideration of the issues of transportation, edging and installation of the pedestal and the column on the Palace Square in St. Petersburg. In addition to the album of illustrations by A. Montferrand, the drawings of Adamini Antonio, Montferrand's assistant, are considered, clarifying some aspects of the ascent. The questions about lifting the Alexander Column sometimes include doubts about the possibility of processing a large granite massif without the use of mechanical equipment. However, familiarity with the methods of manual stone processing presented in various works should convince the reader of the infinite possibilities of a person with a chisel and a hammer, especially if you add to them the perseverance, ingenuity and resourcefulness of the Russian person. In addition, we should remember a somewhat forgotten, but highly respected word -master. The most responsible and spectacular work was the lifting of the Alexander Column, which was the result of a lot of preparatory works. The construction of the platform and the inclined overpass was only part of them. A stone mass was built around the pedestal, which served as the basis for placing the capstans in two concentric circles. After the installation of the column, the finishing of the monument to the final dimensions, grinding and installation of the angel on the top were carried out for two years. Very little is known about these operations, but the presence of scaffolds made it possible to perform work at any height in any weather, and the possibility of processing granite and diabase, and their grinding has already been recalled. The installation of the angel sculpture without the use of hydraulic cranes and helicopters is hopefully no longer in doubt. The next day after the installation, they began to disassemble all the wooden structures. Stairs were built around the main vertical risers. After installation, the stonemasons continued to work with the column. For several months, more than 200 people worked simultaneously. They cut the belts left on the monolith for rolling and lifting, carried out the final finishing according to precise patterns and polished the stone. This article is devoted to the attempt to mathematically justify the possibility of what was achieved at the level of knowledge, skills, mechanisms and technologies of the beginning of the 19th century.

U-Pb age and trace elements composition of titanite from granites of Belokurikhinsky massif, Gorny Altai

As a result of isotope-geochemical study, the age data (U-Pb method, ID-TIMS) of titanite from the first phase granites of the Belokurikhinsky granite massif, Gorny Altai, were obtained for the first time. The concordant value of the titanite age of 255 ± 2 Ma coincides within the margin of error with the previously published results of dating micas from granites of the second and third phases of the Belokurikha massif by the Ar-Ar method (250 ± 3 Ma). At the same time, the results of dating differ significantly from the previously published age values for the granites of the Belokurikha massif (232 ± 5 Ma, U-Pb method for the monofraction of zircon grains; 245 ± 8 Ma, Rb-Sr method for the whole rocks). Therefore, there is every reason to narrow the time interval of the formation of the Belokurikha granite massif to 255-250 Ma. The study of the trace element composition of titanite by SIMS demonstrated their zonal structure. The central part of the titanite grain differs from the rim by a noticeably higher content of REE, Cr, Y, and Nb. The content of V, Zr and Ba decreases to a lesser extent towards the rim, the content of Sr and U remains constant. At the same time, the REE distribution spectra in the central and rim parts are conformal to each other, having a convex spectrum for LREE and a concave one for HREE. Titanite is characterized by a negative Eu-anomaly, the depth of which decreases to the rim of the grain. A negative Eu-anomaly indicates the co-crystallization of titanite and plagioclase. The REE distribution spectra in titanite from the Belokurikha massif correspond to the characteristics of a typical magmatic titanite from granitoids and differ significantly from the distribution spectra in metamorphic titanite.

Uranium-Lead Geochronology on Monacite of Granites of the Lypnyazka Massif and its Framing (Ingul Megablock of the Ukrainian Shield)

The Lipnyazka massif is located in the Dobrovelychkivsky district of the Kirovohrad region, v. Lipnyazka and further south. Structurally, it is located within the Bratskyy Synclinorium of the Ingul megablock and coincides with the Mikhailovsky anticline. The main petrotype of the massif rocks are porphyry-like granites, often with a gneiss-like texture, aplito-pegmatoid, pegmatoid granites and pegmatites. The latter most often form secant vein bodies. Uranium-lead isotopic dating of granitoids of the Lipnyazka granite massif has been performed, with which a number of deposits and ore occurrences of rare elements, primarily lithium, are spatially and probably genetically connected. The age of porphyry-like granites (2032 ± 6 million years), which is the main petrotype of rocks distributed in the area of the village of Limestone and pegmatoid granites (2027 ± 1 million years), which cut porphyry-like in the form of vein bodies. Aplithoid framed granites (2046 ± 8 million years old), common in the area of the mouth of the Sukhyi Tashlyk River (Dobryanka village), are somewhat older. Based on the results of determining the isotopic composition of strontium in the accessory apatite of granites, a conclusion was made about the upper crust source of granites of the Lipnyazka massif (87Sr/86Sr – 0.730-0.785).

ON THE HISTORY OF THE FORMATION OF THE TASH-YARSKY PYRITE-POLYMETALLIC DEPOSIT (SOUTH URALS)

The article considers the geological structure of the Tash-Yarsky pyritepolymetallic deposit located in the northern part of the Magnitogorsky megazone near the large (about 300 km2) Akhunovsky granite massif. The petrographic study of the hornfelses made it possible to identify a number of mineral parageneses containing cordierite, garnet, and biotite, which are installed respectively from the massif contact at a distance no further than 0,6–0,8; 1,2–1,5 and 2,3–2,5 km. Based on the temperature dependence of the maximum iron content of sphalerite, high temperatures of metamorphism (500–610 °С) were obtained for ores. According to garnet-biotite and garnet-cordierite thermobarometers for rocks close to the massif, the transformation temperature is 720–750 °С, and the pressure is 8,9–9,1 kbar. With a distance of 700–850 m from the contact of granitoids, the temperature does not exceed 620–640 °C, and the pressure is 5,3–5,4 kbar; at a distance of 1,3 km, respectively — 550–560 °C and 4,6–4,7 kbar.

Uranium-Lead Age of Granites of Kirovohrad Massif of the Inhul Megablock of the Ukrainian Shield

The porphyry-like biotite-garnet granites (sample KВ-5-1) of the Sokolivkа quarry were studied. The quarry is located in the Kirovohrad granite massif on the southwest of Kropyvnytsky city. The aim of our geochronology investigation is to determine the age of granites of the Kirovohrad massif by the U-Pb isotope method using monazite. The age of granites from Kirovohrad massif by the U-Pb method using monazite has not been determined yet. According to our data, the porphyry granites of the Kirovohrad massif (Sokolivkа quarry) were formed 2034 million years ago. This U-Pb data of the porphyry-like granites is significantly lower than the U-Pb age of the granites from other parts of this massif. This may be due to the multistage formation of the Kirovohrad massif, for example, the Novoukrainskiy and some granite massifs of the Zhytomyr complex from Volyn’ megablock.

Geology, formation conditions, and ore content of the Turgoyak granite massif and carbonaceous deposits of its western framing (South Ural)

The article describes the geological structure of the Turgoyak granitoid massif (γϬС1–2ts), Urenga (RF2ur) and Uytash (RF3uš) suites. In the Late Vendian time the rocks first experienced regional metamorphism under the conditions of the cummingtonite-amphibolite facies at a temperature of 550–595 °C and a pressure of 250400 МПа, and then in local areas — diaftoresis (T=520530 °C and P=130170 МПа). During the formation of the Turgoyak massif (T=770810 °C and P=210250 МПа), the rocks of the Urengin and Uytash suites were subjected to contact metamorphism. This metamorphic processes made the black shale gold to remove from the black shale zone of the amphibole-hornfels facies and caused its redeposition within the albite-epidote-hornfly zone.