Age, composition of rocks, and geological setting of the Snezhnoe beryllium deposit: Substantiation of the Late Paleozoic East Sayan rare-metal zone, Russia   总被引：1，自引：0，他引：1  

V. V. Yarmolyuk  D. A. Lykhin  T. N. Shuriga  A. A. Vorontsov  A. M. Sugorakova 《Geology of Ore Deposits》2011,53(5):390-400

The Snezhnoe phenakite-beryl deposit is one of the highest-grade deposits in the Altai-Sayan beryllium province. This deposit is spatially associated with the alkali granite of the Ognit Complex and localized in the apical part of the granitic pluton. The trace element composition of granite, as well as of Be and Ta-Nb ores was studied. The Rb-Sr age of Be mineralization estimated at 305 Ma is consistent with the time of formation of numerous rare-metal alkali granitic plutons in the Eastern Sayan and the eastern Tuva. The region of these granitic plutons is outlined as the Late Paleozoic East Sayan rare-metal metallogenic zone specialized for Nb, Ta, Be, Li, Zr, Th, and REE mineralization. The East Sayan zone is localized in the marginal part of the Barguzin igneous province and is similar to the marginal zone of this province in composition of igneous associations and metallogenic specialization. The formation of the Barguzin igneous province and the East Sayan metallogenic zone is related to the evolution of the Late Carboniferous-Early Permian mantle plume.  相似文献   

Vendian stage in formation of the Early Caledonian superterrane in Central Asia     

I. K. Kozakov  E. B. Sal’nikova  V. P. Kovach  V. V. Yarmolyuk  I. V. Anisimova  A. M. Kozlovskii  Yu. V. Plotkina  T. A. Myskova  A. M. Fedoseenko  S. Z. Yakovleva  A. M. Sugorakova 《Stratigraphy and Geological Correlation》2008,16(4):360-382

Granitoids and metamorphic rocks of the Baidarik basement block of the Dzabkhan microcontinent are studied in terms of geology, geochronology (U-Pb dating of zircon microfractions and individual grains) and Nd isotopic-geochemical systematics. As is established, the formation history of metamorphic belt (disthene-sillimanite facies) in junction zone of the Baidarik block and Bayankhongor zone of the Late Riphean (～665 Ma) ophiolite association characterizes development of the Vendian (～560–570 Ma) active continental margin. The high-P metamorphic rocks of that time span evidence formation of structures with the Earth’s crust of considerable thickness. In Central Asia, events of the Vendian low-gradient metamorphism are established also in the Tuva-Mongolian massif, Kan block of the East Sayan Mountains, and South Chuya inlier of the Caledonides in the Altai Mountains. Based on these data, it is possible to distinguish the Late Baikalian stage in development of the Early Caledonian superterrane of Central Asia, which antedated the subsequent evolution of this structure during the Late Cambrian-Ordovician. The high-gradient metamorphism that affected most intensively the southeastern part of the Baidarik block can be correlated with the Early Paleozoic (525–540 Ma) evolution of active continental margin and associated development of the Vendian oceanic basins and island arcs of the Ozernaya zone.  相似文献   

Age and magma sources of the post-collisional gabbroids of the Kaakhem magmatic area, Eastern Tuva: First 40Ar/39Ar and Sm-Nd data     

A. A. Mongush  A. M. Sugorakova 《Geochemistry International》2013,51(11):939-943

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Early Permian Age of Nepheline Syenites of the Korgere–Daba Massif (Sangilen Highlands,Tuva)     

Nikiforov  A. V.  Salnikova  E. B.  Yarmolyuk  V. V.  Kotov  A. B.  Sugorakova  A. M.  Anisimova  I. V. 《Doklady Earth Sciences》2019,485(1):235-237

Doklady Earth Sciences - This paper reports on geochronological U–Pb studies of baddeleyite from nepheline syenite of the Korgere-Daba alkaline massif, which is the largest massif within the...  相似文献   

Bastnaesite: a promising U-Pb geochronological tool     

Sal’nikova  E. B.  Yakovleva  S. Z.  Nikiforov  A. V.  Kotov  A. B.  Yarmolyuk  V. V.  Anisimova  I. V.  Sugorakova  A. M.  Plotkina  Yu. V. 《Doklady Earth Sciences》2010,430(1):134-136

Doklady Earth Sciences -  相似文献   

Late Paleozoic alkali-granitic magmatism of Tuva and its relation to intraplate activity within the Siberian paleocontinent     

A. M. Sugorakova  V. V. Yarmolyuk  V. I. Lebedev  D. A. Lykhin 《Doklady Earth Sciences》2011,439(2):1070-1075

Geological, petrologeochemical, and geochronological studies of the rocks from the Shivei alkali-granitic pluton were conducted. A pluton about 500 km² in area is a part of the larger (more than 30 000 km²) Kaakhem magmatic area. The data obtained allow us to characterize the magmatic complex of the Shivei pluton as a bimodal association with picrobasalts, subalkali basalts, and subalkali and alkali granitic rocks differentiated from syenites to leucogranites. The SHRIMP_II zircon dating from quartz syenites and alkali granites indicate the Permian age of the pluton (293.8 ± 3.8 Ma and 297.1 ± 3.8 Ma, respectively). Mafic-alkali-granitic associations similar in age and type, which are traced in the meridional direction along the Eastern Sayan toward the Siberian Platform, were distinguished as the Eastern Sayan zone of the Late Paleozoic alkaline magmatism. Its location corresponds to the western periphery of the Angaro-Vitim batholite and fits well into the zonal structure of the Barguzin magmatic province. We relate the geodynamic position of the Barguzin province with the mantle plume that was overlapped by the edge of the Siberian Pale-ocontinent in the course of its Paleozoic migration above the African hot spot.  相似文献   

The Chailag-Khem fluorite-barium-strontium rare earth carbonatite occurrence, the Western Sayan Range, Russia     

A. V. Bolonin  A. V. Nikiforov  D. A. Lykhin  A. M. Sugorakova 《Geology of Ore Deposits》2009,51(1):17-32

The geological and mineralogical data on the Chailag-Khem F-Ba-Sr-REE occurrence in the Western Sayan Range, Russia, are discussed. The chemical compositions of rocks, ores, and minerals (ICP-MS, Link) are reported. The occurrence is localized in a tectonic crush zone composed of Cambrian quartz-sericite slates intruded by quartz syenite porphyry. Ore mineralization occurs as veins, cement of tectonic breccia, and metasomatic disseminations in host rocks. Massive ore consists of calcite, strontianite, and quartz; impregnations of euhedral fluorite, ankerite, and bastnaesite crystals; and fine-grained barite aggregate. Accessory minerals include parisite, synchysite, barytocelestine, sulfides, rutile, and uraninite. Late metasomatic calcite and strontianite segregations and veinlets are abundant. In genetic, mineralogical, and geochemical features, the Chailag-Khem occurrence is similar to the Late Mesozoic carbonatite deposits of Central Tuva, of which the Karasug Fe-F-Ba-Sr-REE deposit is the largest and best known. All carbonatite deposits and occurrences are located within a longitudinal zone transverse to the major tectonic elements of the region.  相似文献   

Isotope geochemistry (O, C, S, Sr) and Rb-Sr age of carbonatites in central Tuva     

A. V. Nikiforov  A. V. Bolonin  B. G. Pokrovsky  A. M. Sugorakova  A. V. Chugaev  D. A. Lykhin 《Geology of Ore Deposits》2006,48(4):256-276

The Rb-Sr isochron age of igneous ankerite-calcite and siderite carbonatites in central Tuva is estimated at 118 ± 9 Ma. The following ranges of initial values of O, C, Sr, and sulfide and S isotopic compositions were established: δ¹⁸O_carb = +(8.8?14.7)‰, δ¹³C_carb = ?(3.6?4.9)‰, δ¹⁸O_quartz = +(11.6?13.7)‰, δ³⁴S_pyrite = +(0.3?1.1)‰, and (⁸⁷Sr/⁸⁶Sr)_i =0.7042?0.7048 for ankerite-calcite carbonatite and δ¹⁸O_sid = +(9.2?12.4)‰, δ¹³C_sid = ?(3.9?5.9)‰, δ¹⁸O_quartz = +(11.2?11.4)‰, δ³⁴S_pyrite = ?(4.4–1.8)‰, δ³⁴S_sulfate = +(8.6?14.5)‰, and (⁸⁷Sr/⁸⁶Sr)_i = 0.7042?0.7045 for siderite carbonatite. The obtained isotopic characteristics indicate that both varieties of carbonatites are cognate and their mantle source is comparable with the sources of Late Mesozoic carbonatites in the western Transbaikal region and Mongolia. The revealed heterogeneity of isotopic compositions of carbonatites is caused by their contamination with country rocks, replacement with hydrothermal celestine, and supergene alteration.  相似文献   

Andradite–Morimotoite Garnets as Promising U–Pb Geochronometers for Dating Ultrabasic Alkaline Rocks     

E. B. Salnikova  M. V. Stifeeva  A. V. Nikiforov  V. V. Yarmolyuk  A. B. Kotov  I. V. Anisimova  A. M. Sugorakova  V. V. Vrublevskii 《Doklady Earth Sciences》2018,480(2):778-782

U–Pb geochronological studies of garnet of the andradite–morimotoite series and Sm–Nd geochronological studies of this garnet and apatite from the Chikskii Massif (Tuva-Mongolia microcontinent) were carried out. The garnet studied is characterized by relatively high concentrations of U (14–16 ppm) and by a low level of common Pb (Pb_с/Pb_t = 0.07–0.1). The concordia age of garnet is 492 ± 2 Ma (MSWD = 0.01, probability 92%) and matches within the error with the Sm–Nd age determined by the isochrone for apatite, garnet, and bulk rock (489 ± 9 Ma, MSWD = 0.86). This allows us to consider calcic garnets of the andradite–morimotoite series as promising mineral geochronometers for U–Pb dating of ultrabasic alkaline rocks.  相似文献