Тип публикации: статья из журнала

Год издания: 2017

Идентификатор DOI: 10.1016/j.precamres.2017.01.011

Ключевые слова: Baltica, Karelia, Key pole, Nuna/Columbia supercontinent, Paleomagnetism, Paleoproterozoic mafic dykes and sills

Аннотация: Numerous mafic dykes, sills and intrusions with ages between 1985 Ma and 1960 Ma are exposed near the Onega Lake in southern Karelia, Russia. The paleomagnetic analysis of these rocks has revealed a stable remanence with directions belonging to two groups. The directions of the first group characterize ten intrusions including the Показать полностьюdated 1970 ± 3 Ma Unoi sill and 1976 ± 9 Ma Suna River Canyon dolerite, the corresponding paleomagnetic pole is 44.4°N, 101.5°E, A95 = 6.3°. The second group comprises two intrusions including the 1984 ± 8 Ma Pudozhgora intrusion and Krestoviy Navolok dyke with the corresponding paleopole calculated from 5 site mean poles is 60.9°N, 144.8°E, A95 = 6.8°. Both remanence directions are supported by robust baked contact tests. We propose the first group's pole as the key 1975 Ma Fennoscandian pole. The second one is well dated, but based only on two intrusions without proper averaging of the paleosecular variations. We have also carried out a complimentary paleomagnetic study of the previously investigated 2504 Ma Shalskiy gabbronorite dyke. The remanence of this dyke is now supported by the inverse contact test and statistics can be improved. Using our 1975 Ma pole together with coeval poles from Superior, Slave and Amazonia cratons we propose a provisional 1975 Ma paleogeographic reconstruction. © 2017 Elsevier B.V.

Журнал: Precambrian Research

Выпуск журнала: Vol. 292

Номера страниц: 1-12

ISSN журнала: 03019268

Издатель: Elsevier B.V.

• Lubnina N.V. (Faculty of Geology, M.V. Lomonosov Moscow State University, Leninskiye Gory, 1, Moscow, Russian Federation)
• Pisarevsky S.A. (Earth Dynamics Research Group, ARC Centre of Excellence for Core to Crust Fluid Systems (CCFS) and The Institute for Geoscience Research (TIGeR), Department of Applied Geology, Curtin University, GPO Box U1987WA, Australia, Institute of the Earth's Crust, Siberian Branch of the Russian Academy of Sciences, Irkutsk, 128 Lermontov Street, Russian Federation)
• Stepanova A.V. (Institute of Geology, Karelian Research Center, Pushkinskaya st., 11, Petrozavodsk, Russian Federation, Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, RAS, Staromonetny, 35, Moscow, Russian Federation)
• Bogdanova S.V. (Department of Geology, Lund University, Sölvegatan 12, Lund, Sweden, Kazan Federal University, 18 Kremlyovskaya str., Kazan, Russian Federation)
• Sokolov S.J. (Institute of Geology, Karelian Research Center, Pushkinskaya st., 11, Petrozavodsk, Russian Federation)

• Scopus