RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 7, ES4002, doi:10.2205/2004ES000169, 2005
Two competing Paleomagnetic directions in the Late Vendian: New data for the SW Region of the Siberian PlatformA. V. Shatsillo1, A. N. Didenko2, and V. E. Pavlov1
1Institute of Physics of the Earth, Moscow, Russia
2Geological Institute, Russian Academy of Sciences, Moscow, Russia
 New paleomagnetic data have been obtained for the Late Vendian sedimentary rocks of the East Sayan and Southwest Baikal regions in the southwest of the Siberian platform. Two substantially different paleomagnetic components are isolated within the investigated stratigraphic interval in all objects of study. The prefolding age of these components, as well as their difference from all of the known Phanerozoic paleomagnetic directions of the Siberian platform, indicate the almost simultaneous formation of the respective magnetization components during the earliest stages of the existence of these rocks. The angular distance between the paleomagnetic poles calculated for these components is about 45o. The analysis of the World Paleomagnetic Database shows that the presence of the discordant paleomagnetic directions in the Vendian-Early Cambrian rocks is characteristic not only of the Siberian objects but is also manifested in other continents and, hence, can be considered as the phenomenon of the planetary scale. We reckon that this fact can be explained by the anomalous behavior of the magnetic field of the Earth around the Precambrian-Cambrian boundary. In this paper we suggest a model describing the "geometry'' of the Earth magnetic field in the Late Vendian-Early Cambrian, which allows one to explain the observed pattern of the paleomagnetic record.
Received 15 December 2004; revised 10 February 2005; accepted 21 May 2005; published 24 September 2005.
Keywords: paleomagnetism, Vendian, Cambrian, Siberian platform, anomalous geomagnetic field behavior.
Index Terms: 1500 Geomagnetism and Paleomagnetism; 1527 Geomagnetism and Paleomagnetism: Paleomagnetism applied to geologic processes; 9320 Geographic Location: Asia.
Citation: (2005), Two competing Paleomagnetic directions in the Late Vendian: New data for the SW Region of the Siberian Platform, Russ. J. Earth Sci., 7, ES4002, doi:10.2205/2004ES000169.Copyright 2005 by the Russian Journal of Earth Sciences
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