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1.
S. V. Vysotsky V. V. Yakovenko A. V. Ignat’ev A. A. Karabtsov 《Russian Journal of Pacific Geology》2009,3(1):64-68
This paper reports an oxygen isotopic study of corundums and associated minerals from the Yogo lamprophyres (Montana, US), plagioclase-corundum inclusions in alkali basalt (Tunkin depression, Russia), and from modern alluvium of Podgelbanochnyi alkaline basaltic volcano (Primorye, Russia). It is shown that all sapphires genetically related to mafic magmatic rocks have a similar oxygen isotopic composition (the variations of δ18O are within 2.5‰) with most values plotting between +4.5 and +7.0‰ SMOW. The oxygen isotopic ratios in the associated minerals (olivines, pyroxenes, mica, and others) and host rocks are plotted in the same interval. This indicates that the sapphire crystallized during evolution of the parental mafic magma. However, there are xenogenic corundums, which were only transported by basaltic magma to the Earth’s surface. They have a sharply distinct oxygen isotopic composition, which suggests their disequilibrium with the host lavas, and, correspondingly, a different genetic nature. 相似文献
2.
S. A. Kargopolov O. P. Polyansky V. V. Reverdatto I. S. Novikov E. M. Vysotsky 《Doklady Earth Sciences》2016,471(1):1174-1178
Estimates of the P–T parameters of metamorphism, the first results of U–Pb dating of zircons from migmatites of the Teletsk–Chulyshman metamorphic belt, are reported. The age of migmatites from the southern block of the Teletsk–Chulyshman belt is 483.9 ± 5.7 Ma. As is evident from the pressure estimate (≤3–4 kbar), the Chulyshman migmatite–gneiss complex could be an apical part of the thermal–dome structure formed during the Early Ordovician thermal impact of a shallow magmatic basic thermal source, later displaced to the appropriate depth along the thrust at the collisional stage. 相似文献
3.
S. G. Kovalev V. N. Puchkov S. I. Vysotsky S. S. Kovalev 《Doklady Earth Sciences》2018,482(2):1270-1274
New data on the presence of “old” zircons in magmatic rocks of the Shatak Complex have been obtained. This suggests that the evolution of melts in intermediate magma chambers was controlled by the AFC process, in which the liquidus phases (olivine ± clinopyroxene) fractionated, the fluid phases accumulated in the apical part of the chamber, and the host rocks were partly assimilated. Hence, the “old” zircons were entrained from the Archaean–Paleoproterozoic granite–gneiss substrate and trapped by the melt during crustal contamination. 相似文献
4.
Doklady Earth Sciences - New data on the minerals of the Fe–Ni–Co–Cu–S system in the differentiated intrusions of the Southern Urals are presented. Based on a detailed study... 相似文献
5.
S. V. Vysotsky A. V. Barkar V. G. Kuryavy E. A. Chusovitin A. A. Karabtsov P. P. Safronov 《Geology of Ore Deposits》2010,52(8):815-820
The results of the study of hydrothermal noble opal are discussed. it has been established that hydrothermal opal differs
in its nanostructure and formation conditions from exogenic noble opal. The former is composed of smaller globules without
any structuring of closely packed nanoparticles characteristic of exogenic opal. In the course of formation, hydrothermal
opal is affected by pneumatolytic annealing related to the effect of high-temperature vapors under an elevated pressure. At
the same time, the thermal effect results in the formation of two-dimensional photon zones in the chaotic opal matrix. These
photon zones are produced by grids, the cells of which arose from a thermal effect similar to what related to Benard cells.
Precisely, these structured blocks and thin films lead to spectral dispersion of light and appearance of iridescence. 相似文献
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7.
B. Dehandschutter E. Vysotsky D. Delvaux J. Klerkx M. M. Buslov V. S. Seleznev M. De Batist 《Tectonophysics》2002,351(1-2)
Lake Teletskoye in the northeastern part of the Altai mountain range has attracted the attention of geo-scientists for a long time, because it fills an impressive tectonic depression. The lake is 77 km long and 4 km wide, and it has a maximum water depth of 325 m. The vertical offset of the basement surface is up to 3000 m. A multidisciplinary study of the Teletsk graben was carried out during the last few years, including satellite image and air photo analysis, bathymetric-, structural- and geomorphological mapping, high-resolution seismic profiling and seismic refraction. The structural study revealed that reactivation of preexisting weak basement zones is important in controlling the basin formation. These zones separate different tectonic terranes at the contact of which the Teletsk graben developed.This study identifies the significance of the basin in the regional neotectonic context. It shows that the major vertical movements are restricted to the basin itself, but do not characterize the whole region. Outside of the basin, recent tectonic structures have the same pattern as adjacent areas of Northeast Altai and West-Sayan. Quaternary glaciations have had no major influence on the basin formation.Two stages of faulting are identified. First, transpressive movements restricted to discrete (reactivated) fault zones controlled the opening of the basin. In the second stage, normal faulting is dominant and is responsible for the modern basin outline.An echo-sounding survey led to the recognition of several morphological characteristics of the lake bottom. In the southern part, the uppermost sediments seem slightly disturbed, whereas further north, transverse ridges and slope breaks are increasingly common. The deepest part of the lake is located in a highly disturbed zone of normal fault-bounded blocks. The structural difference between the southern and northern subbasins is supported by the interpretation of a deep seismic refraction profile which indicates a substantial increase of basement isochores in the area where the reactivated Teletsk (Paleozoic) shear zone crosses the lake.Correlation of high-resolution seismic profiles suggests that the Teletsk graben started to evolve during the Pleistocene, and that its present shape was formed in two stages. The first stage was responsible for the opening of the southern basin. It probably started in the Middle Pleistocene. A second kinematic stage induced by a sinistral reactivation of the NE striking West-Sayan fault initiated the opening of the different segments of the northern subbasin due to opposite movements between the reactivated Teletsk and West-Sayan faults. This second stage was active after the end of Late Pleistocene glaciations and during the Holocene. The recent lateral extension and the related N–S-trending normal faults result from a change in tectonic regime, with related extensional movements along the main reactivated fault zones. These recent movements result in the lateral escape of the lake borders and the collapse of the area between them. 相似文献
8.
S. G. Kovalev V. N. Puchkov S. I. Vysotsky S. S. Kovalev 《Doklady Earth Sciences》2016,471(2):1247-1252
The noble metal (PGE and Au) geochemical specialization of igneous rocks of the Bashkir meganticlinorium and adjacent areas of the East European Platform is characterized for the first time. The identical plots of normalized PGE and Au concentrations of igneous rocks in these regions indicate similar conditions and mechanisms of the formation of the noble metal geochemical specialization during the emplacement of magmatic bodies. It is established that a specific feature of noble metal geochemical specialization (the “rhodium anomaly”) in magmatic complexes of the Bashkir meganticlinorium and eastern areas of the East European Platform is determined by the concentrations of noble metals in sulfide minerals (pentlandite); i.e., it is “primary” in origin. 相似文献
9.
S. G. Kovalev V. N. Puchkov S. I. Vysotsky S. S. Kovalev 《Doklady Earth Sciences》2017,475(1):743-747
This work presents new data on the conditions of formation of igneous rocks on the western slope of the Southern Urals and the adjacent part of the East European Platform. Based on the calculated P–T melting parameters of the mantle substrate, it is shown that plume magmatism leads to the formation of similar rocks (picrites and picrite-dolerites), while the genesis of them is quite different. The first type of rocks is a product of crystallization of the undifferentiated mantle-derived melt in the upper horizons of the crust; the rocks of the second type are formed as a result of magma differentiation in large intracrustal magma chambers. 相似文献
10.
Detailed characterization of Th–REE mineralization confined to terrigenous deposits of the Shatak complex is presented. For the first time the veinlet xenotime mineralization, unknown in the scientific literature, as well as diverse unidentified Th–REE compounds of variable composition were described in terrigenous deposits. It was concluded that permanent Th and REE admixtures and rare-earth minerals and thorite, respectively, as well as the occurrence of paragenetic intergrowths of Th and REE minerals of variable composition, are evidence that Th–REE mineralization crystallized as a result of the influence of the fluid phase on the sedimentary substrate upon magmatic melt intrusion into the frame rocks. The superimposed dynamothermal greenschist-facies metamorphism led to decay of metastable Th–REE phases without affecting significantly the redistribution of thorium and rare earth elements. 相似文献