共查询到20条相似文献，搜索用时 31 毫秒
1.
Doklady Earth Sciences - New geochronological and geochemical data on the age and composition of undifferentiated Cretaceous volcanics from the Palyavaam River basin, Central Chukotka region, are... 相似文献
2.
Doklady Earth Sciences - In this work we considered the origin of the Verkhoyansk–Kolyma, Chukotka, and Southern Anyui belts, which are part of the Verkhoyansk–Chukotka folded area. It... 相似文献
3.
The data on the structure, geodynamics, and metallogeny of the Khakandzha ore district in northwestern Okhotsk region are analyzed and the two main factors responsible for the localization of ore deposits are defined. The magmatic factor controls the confinement of the ore district to the tectono-magmatic structure of the central type (source of ore matter), which determines the concentric zoning patterns in the distribution of ore mineralization. The tectonic factor determines the confinement of the ore districts, deposits, and ore occurrences of the region to the meridional left-lateral shear structure, which controls the magma and fluid distribution. Local extension (transtension) in this structure against the background of general lateral compression (transpression) provided tectonic environments most favorable for ore accumulation. 相似文献
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5.
O. L. Morozov 《Lithology and Mineral Resources》2000,35(2):163-182
Based on the study of various facies of ancient and modern oceanic sediments, the Ce/La versus Zr/Y criterion is proposed
to discriminate the principal genetic groups of sedimentary rocks in foldbelts and to determine their geodynamic formation
conditions. The structure and composition of siliceous, clayey and fineclastic tuffaceous rocks from various complexes of
paleoaccretionary wedge in the Pekul’nei Range (Chukotka) are discussed. Lithological and geochemical studies of sedimentary
rocks in the Pekul’nei Range allowed us to trace the regular variations in rock sections depending on (1) propagation of oceanic
plate from the spreading center toward the convergent boundary for paleooceanic rock complexes and (2) sedimentation regime
and provenances for rocks deposited above the convergent plate boundary. 相似文献
6.
E. E. Kolova A. V. Volkov N. E. Savva V. Yu. Prokof’ev A. A. Sidorov 《Doklady Earth Sciences》2018,478(2):166-170
The results of thermobaric geochemical study of ores of the Dvoinoye epithermal Au–Ag deposit are considered. Study of the fluid inclusions has shown that the ores were formed from low-salinity hydrothermal solutions with Na, Ka, and Mg chlorides and CO2, HS–, CH4 trace fluxes at the time when the temperature dropped from 370 to 130°C. The results are compared with data obtained from the closely located Kupol and Sentyabr’skoye deposits. 相似文献
7.
G. V. Ledneva B. A. Bazylev V. V. Lebedev N. N. Kononkova A. Ishiwatari 《Geochemistry International》2012,50(1):44-53
The Ust’-Belaya mafic-ultramafic massif is assigned to the Western Koryak fold belt and largely composed of residual spinel
peridotites, layered spinel and plagioclase peridotites, and gabbros. These rocks are crosscut by occasional plagiogranite
and diorite veins and exhibit locally a close spatial association with basalts and carbonate-sedimentary deposits of Late
Devonian and Early Carboniferous age. Based on this evidence, the massif was ascribed to the pre-Late Devonian ophiolite association.
Our study presents new U-Pb SHPIMP II zircon ages and petrographic and mineralogical data on samples of the layered amphibole
gabbro and vein diorite from the Ust’-Belaya massif. The approximate concordant U-Pb age corresponding to a timing of of amphibole
gabbro crystallization is 799 ± 15 Ma, and the concordant U-Pb age reflecting a timing of of vein diorite crystallization
is 575 ± 10 Ma. These ages coupled with geological studies of the massif, petrological and mineralogical investigations of
the dated samples, as well as literature data on the petrology of peridotites and the age of formed plagiogranites suggest
that the peridotites and layered gabbros of the Ust’-Belaya massif were formed by the Late Riphean, whereas the vein diorite
and plagiogranite were resulted from a later (Vendian-Cambrian) magmatic stage. The peridotites and gabbros of the massif
display no genetic relationship with spatially associated basalts and sedimentary rocks and, thus, they cannot be considered
as members the pre-Late Devonian ophiolitic association. The results of this study will inevitably lead to a significant revision
of geological and geodynamic interpretations of the Ust’-Belaya mafic-ultramafic massif. However, uneven study of the Precambrian
complexes of the Koryak and Chukchi areas, their evolution in different structures of the region cannot yet be described by
a single geodynamic scenario. 相似文献
8.
The Ust’-Emuneret floristic assemblage from the Emuneret Formation developed in the Enmyvaam River basin (Okhotsk-Chukotka volcanogenic belt) is described. The age of flora-bearing deposits is debatable, being previously determined in the interval of the Cenomanian to Campanian. According to the new data, the assemblage includes 57 species of fossil plants with dominant angiosperms, subdominant conifers, and subordinate ferns, liverworts, ginkgoaleans, and czekanowskialeans. The Ust’-Emuneret flora is characterized by the presence of advanced forms among different plant groups, which occur in Santonian-Campanian and younger floras of northeastern Russia, and by the presence of relict ginkgoaleans and czekanowskialeans. The flora is compared with other floras from neighboring regions, which provides grounds for the inference on its most probable Late Santonian age (probably, including the Early Santonian and initial Campanian). 相似文献
9.
Vlasov E. A. Ivanova E. S. Mochalov A. G. Yakubovich O. V. 《Doklady Earth Sciences》2022,507(1):881-886
Doklady Earth Sciences - The results of 190Pt–4He dating of placer-forming minerals of platinum (PMP) from the Baimka gold placer cluster (Western Chukotka, Russia) are reported. PMPs are... 相似文献
10.
The first results of SHRIMP dating of magmatic complexes and associated gold–silver deposits and ore occurrences (Kupol, Dvoinoe, Moroshka, and others) in the Chukotka sector of the Russian Arctic coast are discussed. The petrological and isotopic–geochronological data are used for reconstructing their formation conditions. 相似文献
11.
Doklady Earth Sciences - First data on oxygen isotopic composition in phenocrysts in volcanic rocks from Okhotsk–Chukotka volcanic belt (106–78 Ma, North-Eastern Russia) together with... 相似文献
12.
Doklady Earth Sciences - Ores of epithermal Au–Ag deposits of the Okhotsk–Chukotka volcanoplutonic belt are characterized by enrichment in a wide spectrum of elements in relation to the... 相似文献
13.
Geotectonics - The age and geodynamic position of the volcanic source of the Upper Jurassic–Lower Cretaceous deposits of Western Chukotka were determined. Products of synchronous volcanism... 相似文献
14.
Tikhomirov P. L. Lebedev I. E. Lhuillier F. J. L. Pavlov V. E. 《Doklady Earth Sciences》2021,501(2):1059-1064
Doklady Earth Sciences - U–Pb and 40Ar/39Ar age data obtained for volcanic rocks of the Okhotsk–Chukotka Belt in the headwaters of the Malyi Anyui River (the vicinity of Kupol deposit)... 相似文献
15.
Kara T. V. Luchitskaya M. V. Katkov S. M. Belousova E. A. 《Doklady Earth Sciences》2019,487(2):911-916
Doklady Earth Sciences - The Egdygkych hypabyssal rocks of the Nichan and Vuknei massifs, as well as the host volcanites and tuffs of the Oloi volcanic belt of the Alazeya–Oloi folded system... 相似文献
16.
Polin V. F. Tikhomirov P. L. Khanchuk A. I. Travin A. V. 《Doklady Earth Sciences》2021,497(2):273-280
Doklady Earth Sciences - The first data of U/Pb and 40Ar/39Ar dating of volcanogenic rocks of the Pre-Dzhugdzhur volcano-tectonic trough (PDVT) of the Okhotsk–Chukotka volcanogenic belt... 相似文献
17.
Geotectonics - The dunite–wehrlite–clinopyroxenite–gabbro massif in Eastern Chukotka, a key object for geodynamic reconstructions of the Vel’may terrane, which represents... 相似文献
18.
T. N. Palechek A. V. Moiseev S. D. Sokolov 《Stratigraphy and Geological Correlation》2013,21(2):171-188
The analysis of radiolarian assemblages and lithological types of siliceous rocks yielded new data on the structure of different sequences constituting the northern Algan terrane in the Pereval’naya River basin. Three tectonic slices formed by different lithothectonic complexes can be defined in this area. The radiolarian assemblages from the volcanogenic-siliceous slice allow the oceanic section to be dated back to the Kimmeridgian-Valanginian. The tuffaceous-terrigenous slice contains cherts of two types: (1) formed in situ and (2) reworked. The reworked deep-sea cherts yielded Bathonian-Kimmerdgian and Bathonian-Oxfordian radiolarians, while late Aalenian-late Bathonian radiolarian assemblages were extracted from the Kimmerdgian-Tithonian matrix of siliceous rocks. 相似文献
19.
This paper presents data on the inorganic geochemical characteristics of the sediments from Hole LZ1024 (Lake El’gygytgyn,
Chukotka, 67°30′ N 172°08′ E). It is demonstrated how these data are associated with climatic variations during isotope stages
1–9. The sediments of the warm stages are characterized by elevated contents of SiO2, CaO, Na2O, K2O, and Sr and low concentrations of TiO2, Al2O3, MgO, and Fe2O3. It has been established that the geochemical parameters correlate with global climatic variations. 相似文献
20.
A. A. Elmanov V. Yu. Prokofiev A. V. Volkov A. A. Sidorov K. I. Voskresenskiy 《Doklady Earth Sciences》2018,480(2):725-729
The first data on study of individual fluid inclusions in the Zhilnoye deposit have been obtained. It has been found that the gold-bearing quartz veins of the deposit were formed by heterogeneous hydrothermal fluids with low salt concentrations (0.2–3.6 wt% equiv. NaCl under intermediate temperature conditions of 246–350°C). The fluid pressure was 80–160 bar corresponding to 0.3–0.6 km depths of formation under hydrostatic conditions. The parameters of the mineral-forming fluids of the Zhilnoye deposit correspond to typical parameters of the fluids of epithermal deposits. 相似文献