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by V.
Pavlov and Y. Gallet
A
third superchron during the Early Paleozoic
Abstract
Research on geomagnetic reversal chronology has established the
existence of two superchrons, one during the Cretaceous and the
other (Kiaman) during the Late Paleozoic. Over the past few years,
we have performed several magnetostratigraphic studies on Early
Paleozoic (Cambrian and Ordovician) sedimentary sequences from
Siberia. Our results show high magnetic reversal frequencies during
the Middle Cambrian. In contrast, several records show the
occurrence of a ~20 Myr long reversed polarity interval in the Lower
and Middle Ordovician, suggesting the presence of a third superchron.
We propose to give the name of ¡°Moyero¡±to this new superchron; this
name is attributed to the Siberian section which first yielded a
complete record of this reversed polarity interval.
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