MEZOPROTEROZOIC BASITE MAGMATISM OF THE BASHKIRIAN MEGANTICLINORIUM (SOUTHERN URALS): AGE CONSTRAINTS, PETROLOGICAL AND GEOCHEMICAL FEATURES
Among the Riphean–Vendian dyke complexes of the basic composition, which intersect the Precambrian strata of the Bashkirian meganticlinorium (Southern Urals), one of the most common is the Kurgas gabbro-dolerite complex dated to the Early – Middle Riphean. This article presents the isotopic dating,...
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Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust
2020-06-01
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| Series: | Геодинамика и тектонофизика |
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| Online Access: | https://www.gt-crust.ru/jour/article/view/1029 |
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| author | A. O. Khotylev A. V. Tevelev Ya. V. Bychkova A. V. Latyshev M. B. Anosova |
| author_facet | A. O. Khotylev A. V. Tevelev Ya. V. Bychkova A. V. Latyshev M. B. Anosova |
| author_sort | A. O. Khotylev |
| collection | DOAJ |
| description | Among the Riphean–Vendian dyke complexes of the basic composition, which intersect the Precambrian strata of the Bashkirian meganticlinorium (Southern Urals), one of the most common is the Kurgas gabbro-dolerite complex dated to the Early – Middle Riphean. This article presents the isotopic dating, petrological and geochemical features of the rocks belonging to the Kurgas complex. It gives the first description of the regional geochemical zoning that is reflected in a decrease in SiO2 contents from the north to the south along the Bashkirian meganticlinorium, and an increase in MgO contents in the same direction, which is attributed by the authors to an increase in the permeability of the crust to the south during opening of the Mashak riftogenic structure.New data on isotopic ages were obtained for the dyke that cuts the Satka formation of the Lower Riphean – 1318±10 (40Ar/39Ar), the intrusion in the exocontact zone of the Berdyaush rapakivi granite massif – 1349±11 Ma (U-Pb), and the andesite dyke among the metamorphic rocks of the Taratash complex – 1365.6±6.6 Ma (U-Pb). These ages, in combination with the previously obtained data, suggest that the complex formed during a rather long period of time (from 1385 to 1318 Ma, as a minimum), which corresponds to the beginning of the Middle Riphean. Isotopic U-Pb age of the dyke that cuts the contact zone of the Berdyaush massif, suggests that the major portion of the massif had already crystallized by that time and was exhumed into the shallow zone of brittle deformation. |
| format | Article |
| id | doaj-art-a9637ee5b57543f3972f64ff1e29cb6e |
| institution | Matheson Library |
| issn | 2078-502X |
| language | English |
| publishDate | 2020-06-01 |
| publisher | Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust |
| record_format | Article |
| series | Геодинамика и тектонофизика |
| spelling | doaj-art-a9637ee5b57543f3972f64ff1e29cb6e2025-08-04T14:27:23ZengRussian Academy of Sciences, Siberian Branch, Institute of the Earth's crustГеодинамика и тектонофизика2078-502X2020-06-0111221924310.5800/GT-2020-11-2-0471469MEZOPROTEROZOIC BASITE MAGMATISM OF THE BASHKIRIAN MEGANTICLINORIUM (SOUTHERN URALS): AGE CONSTRAINTS, PETROLOGICAL AND GEOCHEMICAL FEATURESA. O. Khotylev0A. V. Tevelev1Ya. V. Bychkova2A. V. Latyshev3M. B. Anosova4M.V. Lomonosov Moscow State UniversityM.V. Lomonosov Moscow State UniversityM.V. Lomonosov Moscow State UniversityM.V. Lomonosov Moscow State University; Schmidt Institute of the Physics of the Earth of RASM.V. Lomonosov Moscow State UniversityAmong the Riphean–Vendian dyke complexes of the basic composition, which intersect the Precambrian strata of the Bashkirian meganticlinorium (Southern Urals), one of the most common is the Kurgas gabbro-dolerite complex dated to the Early – Middle Riphean. This article presents the isotopic dating, petrological and geochemical features of the rocks belonging to the Kurgas complex. It gives the first description of the regional geochemical zoning that is reflected in a decrease in SiO2 contents from the north to the south along the Bashkirian meganticlinorium, and an increase in MgO contents in the same direction, which is attributed by the authors to an increase in the permeability of the crust to the south during opening of the Mashak riftogenic structure.New data on isotopic ages were obtained for the dyke that cuts the Satka formation of the Lower Riphean – 1318±10 (40Ar/39Ar), the intrusion in the exocontact zone of the Berdyaush rapakivi granite massif – 1349±11 Ma (U-Pb), and the andesite dyke among the metamorphic rocks of the Taratash complex – 1365.6±6.6 Ma (U-Pb). These ages, in combination with the previously obtained data, suggest that the complex formed during a rather long period of time (from 1385 to 1318 Ma, as a minimum), which corresponds to the beginning of the Middle Riphean. Isotopic U-Pb age of the dyke that cuts the contact zone of the Berdyaush massif, suggests that the major portion of the massif had already crystallized by that time and was exhumed into the shallow zone of brittle deformation.https://www.gt-crust.ru/jour/article/view/1029ripheanbashkirian meganticlinoriumsouthern uralsdyke swarmsgabbroisotopic dating |
| spellingShingle | A. O. Khotylev A. V. Tevelev Ya. V. Bychkova A. V. Latyshev M. B. Anosova MEZOPROTEROZOIC BASITE MAGMATISM OF THE BASHKIRIAN MEGANTICLINORIUM (SOUTHERN URALS): AGE CONSTRAINTS, PETROLOGICAL AND GEOCHEMICAL FEATURES Геодинамика и тектонофизика riphean bashkirian meganticlinorium southern urals dyke swarms gabbro isotopic dating |
| title | MEZOPROTEROZOIC BASITE MAGMATISM OF THE BASHKIRIAN MEGANTICLINORIUM (SOUTHERN URALS): AGE CONSTRAINTS, PETROLOGICAL AND GEOCHEMICAL FEATURES |
| title_full | MEZOPROTEROZOIC BASITE MAGMATISM OF THE BASHKIRIAN MEGANTICLINORIUM (SOUTHERN URALS): AGE CONSTRAINTS, PETROLOGICAL AND GEOCHEMICAL FEATURES |
| title_fullStr | MEZOPROTEROZOIC BASITE MAGMATISM OF THE BASHKIRIAN MEGANTICLINORIUM (SOUTHERN URALS): AGE CONSTRAINTS, PETROLOGICAL AND GEOCHEMICAL FEATURES |
| title_full_unstemmed | MEZOPROTEROZOIC BASITE MAGMATISM OF THE BASHKIRIAN MEGANTICLINORIUM (SOUTHERN URALS): AGE CONSTRAINTS, PETROLOGICAL AND GEOCHEMICAL FEATURES |
| title_short | MEZOPROTEROZOIC BASITE MAGMATISM OF THE BASHKIRIAN MEGANTICLINORIUM (SOUTHERN URALS): AGE CONSTRAINTS, PETROLOGICAL AND GEOCHEMICAL FEATURES |
| title_sort | mezoproterozoic basite magmatism of the bashkirian meganticlinorium southern urals age constraints petrological and geochemical features |
| topic | riphean bashkirian meganticlinorium southern urals dyke swarms gabbro isotopic dating |
| url | https://www.gt-crust.ru/jour/article/view/1029 |
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