New Siberian Paleomagnetic Poles for 1050-1100 Ma: Further Testing of the Siberia-Laurentia Mesoproterozoic Connection.

Abstract:

The similarity of Siberian and Laurentian APWPs for the ~1050-950 Ma interval is, probably, the most strong among available to date scanty evidence for placing the Siberian platform into the Rodinia supercontinent. There are numerous Laurentian paleomagnetic poles with ages 1150-1050 Ma. However, Siberian paleomagnetic poles for this period are virtually absent, that hampers further paleomagnetic testing of the hypothesis of Siberian- Laurentian Mesoproterosoic connection within the Rodinia. In order to develop the Late Mesoproterosoic Siberian APWP we have undertaken paleomagnetic study of red siltstone of the Totta Formation from the Belaya River valley (northern part of the Uchur-Maya region, eastern disturbed margin of the Siberian platform). The Totta Fm contain detrital zircons with younger ages ~1100 Ma and underlies the Malgina Fm with a reported Pb-Pb age is 1043+-14 Ma. Thus age of the Totta Fm can be estimated to be between 1050 and 1100 Ma. At the same time in order to estimate possible vertical axes rotations of the study area relatively to the Siberian platform we have studied limestones of the Malgina Fm, which paleomagnetic pole for the platform part of the Uchur-Maya region is well known. In our report we present new obtained data and discuss their significance for verification of the Laurentia-Siberia mesoproterosoic connection hypothesis.