A new key pole for the East European Craton at 1452 Ma: Palaeomagnetic and geochronological constraints from mafic rocks in the Lake Ladoga region (Russian Karelia) |
| |
| Authors: | Natalia V Lubnina Satu Mertanen Ulf Söderlund Svetlana Bogdanova Tatiana I Vasilieva Dmitry Frank-Kamenetsky |
| |
| Institution: | 1. Department of Dynamic Geology, Moscow State University, Leninskiye Gory, Moscow 119992, Russia;2. Geological Survey of Finland, P.O. Box 96, FI-02151 Espoo, Finland;3. Department of Earth and Ecosystem Sciences, Lund University, Sölvegatan 12, SE 22362 Lund, Sweden;4. Geological Institute RAS, Pygevsky per., 7, Moscow 119017, Russia;5. State Company “Mineral” St. Petersburg, Russia |
| |
| Abstract: | Palaeomagnetic and geochronological studies on mafic rocks in the Lake Ladoga region in South Russian Karelia provide a new, reliably dated Mesoproterozoic key paleopole for the East European Craton (Baltica). U–Pb dating on baddeleyite gives a crystallisation age of 1452 ± 12 Ma for one of the studied dolerite dykes. A mean palaeomagnetic pole for the Mesoproterozoic dolerite dykes, Valaam sill and Salmi basalts yields a paleopole at 15.2°N, 177.1°E, A95 = 5.5°. Positive baked contact test for the dolerite dykes and positive reversal test for the Salmi basalts and for the dykes confirm the primary nature of the magnetisation. Comparison of this Baltica palaeopole with coeval paleomagnetic data for Laurentia and Siberia provides a revised palaeoposition of these cratons. The results verify that the East European Craton, Laurentia and Siberia were part of the supercontinent Columbia from the Late Palaeoproterozoic to the Middle Neoproterozoic. |
| |
| Keywords: | Palaeomagnetism Mesoproterozoic East European Craton Baltica U&ndash Pb baddeleyite Columbia |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
