The LA–ICP–MS U–Pb age was determined for the first time for zircon from granodiorites–granites of the Sardara (Sarykty) intrusive in area of the giant Muruntau gold deposit in Western Tien Shan ...(Uzbekistan). Three crystal groups were identified in a combined sample: their concordant U–Pb age is 322.0 ± 3.7 (four grains), 301.6 ± 2.1 (11 grains), and 289.5 ± 4.9 Ma (two grains) (MSWD = 3.1, 0.17, and 0.98, respectively). The dispersion of the isotopic age can be explained using a model of a successive crystallization of different zircon generations in magmatic chambers at various depths and their further entrapment upon differentiation/crystallization of new magma portions. The similarity of two (youngest) age intervals with concordant U–Pb ages previously published for zircons of granitoid rocks directly at the Muruntau deposit is noteworthy. The latter ages could thus represent dike branching at the corresponding stages of evolution (progressive differentiation) of deeper sources of granitoid magma, the larger intrusions of which include Sardara (Sarykty) and other plutons exposed at some distance from the deposit. The older U–Pb isotopic ages of zircons from granitoids of the Sardara (Sarykty) pluton (~322 and 302 Ma) generally correspond to the subduction stage, whereas the youngest zircons (~289.5 Ma) correspond to the postcollision stage of the region. The origination and initial evolution of the magmatic sources in area of the Muruntau deposit could thus occur under subduction conditions; however, the final differentiation and crystallization of granitoid magma has finished at the postcollision stage.
The paper presents isotopic U–Pb zircon data (LA-ICP-MS method) for the main types of high-potassic intrusive rocks of the Chorukh-Dairon W–Mo(–Cu–Au) skarn deposit situated in the Kurama segment of ...the Middle Tien Shan near the largest porphyry Cu–Mo–Au deposits of the Almalyk mineralized cluster. Together with the other Au, W, Mo and Cu deposits, all these deposits are parts of the extended Late Paleozoic metallogenic belt of Tien Shan. The concordant isotopic U–Pb zircon data obtained for the rocks of successive intrusion phases in the Chorukh-Dairon pluton span from about 298 Ma to 290 Ma. This interval included crystallization of monzodiorite (295.1 ± 3.3 Ma), quartz syenite (294.7 ± 2.3 Ma), quartz monzonite (294.1 ± 2.1 Ma), and monzogranite (293.0 ± 3.0 Ma). These dates correspond to the pluton emplacement at the Late Carboniferous-Early Permian boundary and highlight its younger age compared to the productive high-potassic intrusions of the porphyry Cu–Mo–Au deposits in the Almalyk mineralized cluster, the latter assigned to the Late Carboniferous (about 337–313 Ma and partially to 308–297 Ma). By contrast to the latter, which were intruded in the subduction-related environment, the emplacement of the high-potassic rock of the Chorukh-Dairon pluton occurred in the transitional subduction-related to post-collisional environment or even under an actual post-collisional regime. This allows distinguishing two pulses of ore-bearing Carboniferous-Permian high-potassic calc-alkaline to shoshonitic series magmatism in the Middle Tien Shan. Consistently, there is a metallogenic evolution in the region that was expressed in the transition from porphyry Cu–Mo–Au deposits associated with subduction-related potassic magmatism, and likely evolving toward epithermal Au-Ag deposits, to essentially tungsten (W–Mo–Cu–Au) deposits associated with younger potassic magmatism occurring rather in the post-collisional environment.
The distribution of index minerals of the hydrothermal arsenide process of the formation of Ni‒Co–As (±U–Ag), Co–S–As (±Au–W), and Cu–Co–As (±Sb–Ag) quartz–carbonate veins of deposits of the Bou ...Offro–El Graara ore belt (Morocco) are discussed. The Co arsenide objects of the Bou Azzer ore cluster with typical low-temperature Ni–Co–As (U–Ag) deposits of the five-element hydrothermal type are of special interest: El Jir, Mechoui, Tarouni, Central and East Bou Azzer, Aghbar, Tamdrost, etc. The ores of most of the studied deposits are strongly enriched in Co relative to Ni (Co/Ni ratio = 10/1), have high grades of Au (up to 100 g/t) and Mo (up to 0.1%) with relatively low Ag, Ni, and U contents. Based on the analysis of the interrelations of ore and gangue minerals, the sequence of the formation of mineral assemblages is identified and their mineralogical–geochemical zonation is studied. The range of the most favorable physicochemical parameters of ore deposition is determined from the fluid inclusions in the gangue minerals. The indicative role of mineralogical–geochemical features of ore assemblages is shown for the forecast and survey of blind ore bodies.
The paper presents new isotopic U–Pb data (LA-ICP-MS method) of zircon from the main types of intrusive rocks at the Kuru-Tegerek gold-copper-molybdenum skarn deposit situated in the Chatkal segment ...of the Middle Tien Shan. This and other gold, copper, tungsten and molybdenum deposits are parts of the extended Late Paleozoic metallogenic belt of Tien Shan. The concordant isotopic U–Pb values obtained for zircon autocrysts from the rocks of sequential intrusive phases span over the interval from approximately 323 to 311 Ma. This interval comprises the crystallization of gabbro-diorite (from 323.5 ± 2.5 Ma to 323.2 ± 6.8 Ma) and tonalite (from 321.4 ± 3.8 Ma to 311 ± 3.8 Ma). The age dates obtained for these zircon autocrysts correspond to the emplacement of these moderate-potassic intrusions in the Late Carboniferous and are almost coincident with the isotopic dates previously known for the high-potassic intrusions of the porphyry Cu–Au–Mo deposits of the Almalyk mineralized cluster (Kurama segment of the Middle Tien Shan), which were also emplaced in the Late Carboniferous (about 330–310 Ma). This corresponds to the subduction tectonic regime occurred in this region in relation to the steep-dipping (in the Kurama segment) or flat (in the Chatkal segment) subduction of a tectonic plate toward the north, under the structures of the Kazakhstan–North Tien Shan continental massif and accreted segments of the Middle Tien Shan. The intrusive rocks studied at the Kuru-Tegerek deposit contain also zircon xenocrysts (including these in the core of complex crystals) with the isotopic U–Pb age of some 1.9–2.1 Ga. These dates are in agreement with the age of metamorphic rocks in the Tarim craton basement and indicate the presence of the ancient continental crust in this segment of the Middle Tien Shan.
The paper presents the isotopic U–Pb study data (LA-ICP-MS method) of zircon from intrusive rocks of the Sonkul and Kokturpak plutons situated along the deep-seated fault system of the “Nikolaev ...Line” in the eastern Kyrgyzstan. These plutons of high-potassic rocks are spatially and genetically associated with the Kumbel and Kashkasu W–Mo–Cu–Au deposits, respectively, as well as other occurrences of W and W–Au mineralization. Together with other Au, W and Cu deposits, they are parts of the extended metallogenic belt of Tien Shan. The concordant isotopic U–Pb ages of zircon autocrysts for the consecutive intrusive phases span over the interval of approximately 303 to 283 Ma. This interval included the crystallization of olivine gabbro (299 ± 2 Ma) in the Sonkul pluton, monzonite (300 ± 3 Ma) in the Kokturpak pluton, granodiorite of the main intrusive phase (299 ± 3 Ma in the Sonkul pluton and 297 ± 4 Ma in the Kokturpak pluton), and monzogranite (289 ± 4 Ma in the Sonkul pluton and 285 ± 2 Ma in the Kokturpak pluton). Zircon antecrysts dated at 306–311 (to 323?) Ma have also been distinguished. The age data obtained correspond to the pluton emplacement in the Late Carboniferous-Early Permian initially in subduction-related and then post-collisional tectonic settings. Besides, in the Middle Tien Shan, this age interval corresponds to one of the regional pulses of high-potassic calc-alkaline and shoshonitic magmatism. A distinct metallogenic evolution corresponds to these pulses that is expressed in the change from porphyry Cu–Au–Mo deposits related to the early pulse to essentially tungsten (W–Mo–Cu–Au) and then essentially gold deposits related to younger pulses. The rocks also contain zircon xenocrysts with ancient age (in the order of 1.5–2.5 Ga) that probably represent the age of the Tarim craton basement.
We studied the effect of KDM5 family demethylase inhibitors (JIB-04, PBIT, and KDOAM-25) on the penetration of SARS-CoV-2 pseudotyped viruses into differentiated Caco-2 cells and HEK293T cells with
...ACE2
hyperexpression. The above drugs were not cytotoxic. Only KDOAM-25 significantly reduced virus entry into the cells. The expression of
ACE2
mRNA in Caco-2 significantly increased, while
TMPRSS2
expression did not significantly change under these conditions. In differentiated Caco-2 cells, KDOAM-25 did not affect the expression of
BRCA1
,
CDH1
,
TP53
,
SNAI1
,
VIM
, and
UGCG
genes, for which an association with knockdown or overexpression of KDM5 demethylases or with the action of demethylase inhibitors had previously been shown. In undifferentiated Caco-2 cells, the expression of
BRCA1
,
SNAI1
,
VIM
, and
CDH1
was significantly increased under the action of KDOAM-25.
The genetic diversity of the structure and mineral composition of the ores of the Gorevskoe Pb–Zn deposit and the main signs of synchronous ore deposition from near-bottom ore-bearing solutions ...associated with sedimentation processes in a sedimentary basin were established. The structural and textural features and mineral associations of ores accompanying different metamorphic and postore processes are discussed. The succession of hydrothermal synsedimentation origin of the Gorevskoe Pb–Zn deposit during the direct deposition from near-bottom ore-bearing solutions is considered in more detail. It is suggested that two types of ores, varying in material composition, textural–structural features, morphology, and location reflect the ore-facies zoning of the unified ore-hydrothermal system. The banded Pb–Zn ores belong to the distal parts of the system; brecciated, mainly Pb, ores—to the proximal ones. The important role of the postore processes of regional and dynamothermal metamorphism in the transformation and redistribution of primary sedimentary ores was revealed. This research is based on the detailed study of textural–structural features of ores in polished and ground samples. The modern research methods were applied to examine microtextural and mineral features and composition of ore and nonmetallic minerals. In general, the ores of the Gorevskoe deposit demonstrate the structural and textural features of synsedimentary deposition, synchronous with the formation of host carbonaceous–micaceous–siliceous–carbonate rocks, preserving the main structural features at both the macro and micro levels. The results obtained are compared and analyzed with other polymetallic deposits of Russia and other regions worldwide.
We have considered a permutation entropy method for analyzing chaotic, noisy, and chaotic noisy series. We have introduced the concept of permutation entropy from a survey of some features of ...information entropy (Shannon entropy), described the algorithm for its calculation, and indicated the advantages of this approach in the analysis of time series; the application of this method in the analysis of various model systems and experimental data has also been demonstrated.
A vircator-based microwave oscillator with a nonlaminar electron beam and an extended matched section of a helical slow-wave system was studied numerically and experimentally. It is shown that the ...oscillator efficiency in the frequency range of 1–3 GHz reaches 20%.
