Regarding the age and composition of gneisses from the basement of West-Siberian Plate’s north-western part
| Autor: | K. S. Ivanov, Yu. V. Erokhin, D. V. Elizarov, S. P. Shokal'sky |
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| Jazyk: | English<br />Russian |
| Rok vydání: | 2016 |
| Předmět: | |
| Zdroj: | Литосфера, Vol 0, Iss 1, Pp 59-73 (2016) |
| Druh dokumentu: | article |
| ISSN: | 1681-9004 2500-302X |
| Popis: | The plagiogneiss mineralogy from the Yangiyuganskaya parametric borehole (the West-Siberia north-western part) has been studied. The rocks are composed of quartz-oligoclase aggregate with presence of mica (muscovite and phlogopite), amphibole (edenite-ferroedenite-ferropargasite), clinozoisite-epidote, garnet (almandine-grossular series), clinochlore, microcline, magnetite, titanomagnetite, rutile and fluorapatite. It is shown that plagiogneisses have been formed from leucocratic plagiogranites under the conditions of the metamorphism of amphibolite facies. U-Pb, Sm-Nd, Rb-Sr plagiogneiss datings point with the biggest possibility to the following main events of geological history of these rocks formation: 1) magmatic intrusion of plagiogranites in Vendian; Sm-Nd isochrone 691 ± 58 Ma also points to neoproterozoic age of the plagiogneiss initial substance; 2) the metamorphism of plagiogranites and its turning into plagiogneisses involved in early Ordovician (486 Ma); 3) the latest tectonothermal events (292 ± 23 Ma), fixed by Rb-Sr system are associated possibly with collision processes. |
| Databáze: | Directory of Open Access Journals |
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