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First findings of siegenite (CoNi2S4) in picritic and picrodoleritic complexes of the Southern Urals
This work presents data on the sulfide mineralization of picritic and picrodoleritic complexes of the western slope of the Southern Urals. The first finding of siegenite is described in igneous mafic-ultramafic rocks. The problems of the genesis of sulfides are reviewed with regard to the origin of igneous bodies. It is concluded that Co specialization of sulfides is caused by the formation of magma under the melting of the mantle substrate during the Riphean-Vendian plume origination and rifting. 相似文献
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I. V. Golovanova K. N. Danukalov V. I. Kozlov V. N. Puchkov V. E. Pavlov Y. Gallet N. M. Levashova G. S. Sirota R. R. Khairullin M. L. Bazhenov 《Izvestiya Physics of the Solid Earth》2011,47(7):623-635
We have carried out paleomagnetic studies of the Upper Vendian sedimentary rocks from the Bashkirian Meganticlinorium (Southern
Ural). The rocks were sampled at three localities spread over more than 100 km. Totally, more than 300 samples were collected
from about 40 sampling sites. Stepwise thermal demagnetization up to 700°C revealed a stable component of magnetization of
either polarity in 25 sites. The fold test and the reversal test for this component are positive, which is usually regarded
as a sound argument in favor of the primary origin of magnetization. However, the Basu paleomagnetic pole (longitude 187.3°E,
latitude 1.1°N) is located near the Late Ordovician-Early Silurian segment of the apparent polar wander path for Baltica,
which might indicate a Paleozoic remagnetization of Vendian rocks. In this work we analyze different interpretations of the
obtained results and evaluate the reliability of the Late Riphean and Vendian paleomagnetic data for Baltica. 相似文献
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A. A. Krasnobaev V. N. Puchkov N. D. Sergeeva E. N. Lepekhina 《Doklady Earth Sciences》2013,450(1):531-535
In this study we discuss the problem of dating the Kiryabinka complex. The data collected on zircons from pyroxenites of the Kiryabinka polyphase pyroxenite-gabbro complex can help address a number of controversial issues regarding the Precambrian geology of the Southern Urals. First, the age of the complex (T = 680 ± 3.4 Ma) can be assigned within the late Riphean (RF4, Arshinian) or the middle Neoproterozoic (Cryogenian). The available zircon dates from gabbroic and granitoid rocks in the western flank of the Southern Urals (Berdyaush, Akhmer, and Barangul massifs) are supplemented with a new age of ultramafic rocks, the differentiates of a basaltic magma, which further corroborate the conclusion about the Upper Riphean age of the country rocks. 相似文献
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K. N. Malitch I. Yu. Badanina V. N. Puchkov E. A. Belousova A. A. Stepashko 《Doklady Earth Sciences》2017,475(1):762-765
The compositional and isotope–geochemical features of zircons from wehrlite of the Feklistov massif, which formed platinum coastal placers, are discussed in this paper for the first time. Zircons from wehrlite of the Feklistov massif, similarly to worldwide zoned clinopyroxenite–dunite massifs, are characterized by different morphology, composition and a wide spectrum of ages (from 2.717 to 0.373 Ga). The Late Devonian age (373.2 ± 7.5 Ma) of zircons allows us to characterize the timing of the formation of wehrlite from the Feklistov massif and to correlate its emplacement with a significant superplume event, which covered the Siberia and Laurussia continents. The geological meaning of this dating refers to limiting the lower age boundary for emplacement of the Feklistov clinopyroxenite–dunite massif into the Earth’s crust, which does not contradict geological observations. 相似文献
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The Rb–Sr and 147Sm–143Nd age data obtained for sheeted dolerite dykes and rocks of the Platinum Belt of the Urals within the Tagil segment of the paleoceanic spreading structure (Middle Urals) are discussed. The study of the Rb–Sr isotope systematics of gabbro allowed us to reveal errochronous dependencies, which yielded ages of 415 and 345 Ma at (87Sr/86Sr)0 = 0.70385 ± 0.00068 and 0.7029 ± 0.0010, correspondingly. The 147Sm–143Nd isotope age data demonstrate a specific coincidence of the chronometric ages of the sheeted dolerite dyke complex (426 ± 54, 426 ± 34, and 424 ± 19 Ma) and gabbro from the Revda gabbro–ultramafic massif (431 ± 27 Ma) and from screens between dolerite dykes in the sheeted dyke complex (427 ± 32 Ma, 429 ± 26 Ma). The proximity of the 147Sm–143Nd ages of gabbro and dolerite can be explained by the thermal effect of the basaltic melt, which is the protolith for the dyke complex, on the hosting gabbro. 相似文献
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Krasnobaev A. A. Puchkov V. N. Sergeeva N. D. Busharina S. V. 《Doklady Earth Sciences》2019,486(2):687-691
Doklady Earth Sciences - The lack of reliable geochronological data for the Vendian deposits of the Urals and other regions is one reason why there is still uncertainty in the age estimates of the... 相似文献
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