POSSIBLE EVIDENCE FOR THE EXISTENCE OF VOLCANOGENIC MAGMATISM IN THE SINYAYA RIVER BASIN AT THE SOUTHERN FLANK OF THE VILYUI SYNECLISE

• Main Authors: V. V. Baranov, V. S. Grinenko, V. P. Afanasiev, S. S. Ugapieva, N. P. Pokhilenko, N. V. Popov, N. V. Zayakina, T. I. Vasilieva, В. В. Баранов, В. С. Гриненко, В. П. Афанасьев, С. С. Угапьева, Н. П. Похиленко, Н. В. Попов, Н. В. Заякина, Т. И. Васильева
• Other Authors: The work was carried as part of the state assignment of the IGM SB RAS (No. 1220414001557-9), IPGG SB RAS and DPMGI SB RAS (No. FUEM-2019-0001, FUEM-2019-0002) with the financial support of the Ministry of Education and Science of the Russian Federation and the Russian Foundation for Basic Research (grant 18-05-70063)., Работа выполнена в рамках госзадания ИГМ СО РАН (№ 122041400157-9), ИНГГ СО РАН, ИГАБМ СО РАН (№ FUEM-2019-0001, FUEM-2019-0002) и профинансирована Минобрнауки РФ, а также при поддержке гранта РФФИ (№ 18-05-70063).
• Format: Article in Journal/Newspaper
• Language: Russian
• Published: Institute of the Earth's crust of the Russian Academy of Sciences, Siberian Branch 2023
• Subjects: Синское поднятие; volcanic pipe; xenolithe; Vilyui syneclise; Sinsk uplift; трубка взрыва; ксенолит; Вилюйская синеклиза; Aldan; Sinyaya; Stanovoy; lena river
• Online Access: https://www.gt-crust.ru/jour/article/view/1742; https://doi.org/10.5800/GT-2023-14-5-0719

The results of different-extension geological survey, exploration and thematic work methods show that the Vilyui syneclise is relatively amagmatic. However, the recent factual evidence in this region indicates the occurrence of magmatism of a different composition and age. This evidence includes kimberlite indicator mineral found in the sedimentary cover of the syneclise. Kimberlites or magmatic rocks of a different composition are not yet known there, so that any other signs of the presence of this type of rocks therein are of importance. As such a sign the authors consider a boulder of metamorphic rock found in the Archean greenstone succession in the lower reaches of the Sinyaya River at the southeastern flank of the Vilyui syneclise. The rock is similar in its mineral composition to garnet-staurolite-kyanite schist typical of the Barrovian metamorphic rocks series. The rocks of this mineral composition are common in the greenstone belts of the Aldan-Stanovoy Shield. In particular, they are typical of the Tungurchin metapelite unit of the TemulyakitTungurchin greenstone belt exposed in the western part of the shield. The straight line distance between the sratotype area of the Tungurchin Formation development and the place where the boulder was found is more than 600 km southwest of the Sinyaya River. So it is unlikely that the boulder was just transported along the Lena River basin and then to the Sinyaya River by, for example, the Quaternary glacial ice. A more realistic way the boulder appeared in the place where it was found would be its transportation from depth by volcanic pipe, i.e. the boulder is a xenolith from volcanic pipe. The volcanic pipe can be within a radius of a few tens of kilometers or less. The Archean basement therein lies at at a depth of a few hundreds of meters to 100 meters which implies transportation of so large xenolith to the surface during the volcanic pipe formation. Therefore, it can be implied that magmatic events occurred in the form of the Jurassic-Cretaceous or probably ...