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Abstract: We summarize the results of paleomagnetic and sedimentological studies of the Neoproterozoic rhythmic terrigenous-carbonate rock unit in the Karagas Supergroup, which were carried out in the middle reaches of the Biryusa and Uda Rivers. The paleomagnetic data are presented along with a detailed description of the studied sections and the specific sedimentological characteristics of the studied deposits. The new data refine the position of Late Precambrian paleomagnetic poles in Siberia and mark the paleogeographic and facies features of the rock unit formation. They also show that the rock unit was deposited much more rapidly than it was supposed earlier, in the environment of shallow-water sea basin on the margin of the Siberian continent. The origin and evolution of the Karagas sedimentary basin was governed by both global and regional tectonic factors. We suppose that the onset of the basin can be linked to a tectonic event, namely, the opening of ocean in southern Siberia during the break-up of Rodinia. Regional tectonic processes controlled the position of the Karagas sedimentary basin and its evolution. The position of the mean paleomagnetic pole (Plat = 3.9°, Plong = 292.3°, A95 = 7.1°) confirms the corresponding interval of the Neoproterozoic trend of APWP in Siberia and proves the near-equatorial position of the continent in Karagas time. [Copyright &y& Elsevier]

Abstract: Rock complexes in Mongolia experienced two remagnetization events. Almost all secondary remanence components of normal polarity were acquired apparently in the Cenozoic, after major deformation events, and those of reverse polarity were associated with intrusion of bimodal magmas during the Late Carboniferous–Permian reverse superchron. Active continental-margin sequences in some areas of Mongolia were folded prior to the Late Carboniferous–Permian magnetic event. The primary origin of magnetization in Late Paleozoic and Mesozoic rocks has been inferred to different degrees of reliability. According to paleolatitudes derived from most reliable paleomagnetic data, the analyzed rocks were located far north of the North China block throughout the Late Paleozoic and Early Mesozoic. Mongolia, as well as Siberia, moved from the south to the north in the Paleozoic, back from the north to the south between the latest Triassic and the latest Jurassic, and remained almost within the same latitudes in Cretaceous and Cenozoic time. These paleolatitudes show no statistical difference from those for the Siberian craton at least since the latest Permian (275–250 Ma). Older Mongolian complexes (with ages of 290, 316, and 330 Ma) likewise may have formed within the Siberian continent, which makes their paleomagnetic determinations applicable to calculate the polar wander path for Siberia. The paleolatitudes of Early Carboniferous sediments in Mongolia differ significantly from those of Siberia, either because of overprints from the reverse superchron or because they were deposited away from the Siberian margin. [Copyright &y& Elsevier]

Abstract: We report a new paleomagnetic determination of Paleoproterozoic rocks from the Siberian craton which showed a positive baked contact test and a stable age of the high-temperature NRM component. The mean paleomagnetic pole of Siberia for ∼1730 Ma located at 42.9° S, 109.6° E (α95 = 5.3°) is compatible with the pole positions obtained recently for the middle and late Early Proterozoic. [Copyright &y& Elsevier]

Abstract: The paper summarizes paleomagnetic results obtained from the Neoproterozoic rocks of the western margin of the Siberian craton. On the basis of the obtained paleomagnetic poles and available paleomagnetic data for the Precambrian of Siberia, a new version of the Neoproterozoic segment of the apparent polar wandering path (APWP) is proposed for the craton and is compared with the Laurentian APWP. The superposition of these paths suggests that in the Neoproterozoic the southern margin of the Siberian craton (in modern coordinates) faced the Canadian margin of Laurentia. Most likely, in the end of the Mesoproterozoic and during the Neoproterozoic the Siberian craton and Laurentia were connected to form the supercontinent Rodinia. At 1 Ga the western margin of the Siberian craton was a northern (in modern coordinates) continuation of the western margin of Laurentia. The available paleomagnetic data on Laurentia and continental blocks of Eastern Gondwana (Australia, Antarctica, India, South China) and the proposed APWP trend allowed a new model for the breakup of this segment of Rodinia. Analysis of a total of the data available suggests that strike-slip movements on the background of the progressive opening of the oceanic basin between Siberia and Laurentia were predominant in the south of the Siberian craton during the Neoproterozoic. Similar kinematics is typical of the western margin of Laurentia, where strike-slip motions are probably associated with the progressive opening of the ocean basin between Laurentia and eastern Gondwana. [Copyright &y& Elsevier]