Article ID Journal Published Year Pages File Type
4722829 Precambrian Research 2015 20 Pages PDF
Abstract

•The 1720 and 1732 Ma new paleomagnetic poles for the Siberian craton are reported.•The Ulkan massif rotated clockwise by 70 ± 8° in the interval 1732–1720 Ма we propose.•The Siberian Paleoproterozoic APWP has been generated using 12 new poles.

Paleomagnetic studies on Paleoproterozoic rocks of the Ulkan massif from the south-eastern Siberian platform yielded two ancient paleomagnetic directions and made it possible to calculate poles corresponding to them for two time intervals in the late Paleoproterozoic: (а) ∼1732 Ma for volcanogenic-sedimentary rocks of the Elgetey Formation – Plat = 7.1° (−7.1°), Plong = 183.5° (3.5°), dp = 10.5°, dm = 16.4° (positive fold, reversals and conglomerates tests); and (b) less than 1720 Ma for granites of the Ulkan Complex – Plat = 42.1° (−42.1°), Plong = 249.4° (69.4°), dp = 3.4°, dm = 5.6°. The analysis of the existing paleomagnetic data for Siberia in late Paleoproterozoic–early Mesoproterozoic times allowed a total of 12 new poles to be defined with five of them considered key poles (Table 3), based on which the APWP for Siberia was generated. On the basis of the data presented here, one can conclude that in the context of the Paleoproterozoic supercontinent model, preference is given to the position of Paleoproterozoic north poles of Siberia in the Indian Ocean and Australia, rather than in the Atlantic Ocean.

Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Geochemistry and Petrology
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