Comment on ‘New palaeomagnetic result from Vendian red sediments in Cisbaikalia and the problem of the relationship of Siberia and Laurentia in the Vendian’ by S. A. Pisarevsky, R. A. Komissarova and A. N. Khramov

Pisarevsky et al. (2000) document a poorly dated pole from Vendian-age sedimentary rocks in Siberia and argue for a lowlatitude position of both Laurentia and Siberia during the interval from 650 to 550 Ma. Their argument is based, at least in part, on a reinterpretation of palaeomagnetic poles from Laurentia because previous studies (e.g. Symons & Chiasson 1991; Meert et al. 1994; Torsvik et al. 1996) argued for a high latitude position for Laurentia beginning at 580 Ma (perhaps earlier). The new data provided by Pisarevsky et al. (2000) are a welcome addition to the Siberian palaeomagnetic database; however, given the broad age range of their result, we feel that the authors over-interpret the extant data in an effort to rescue a controversial positioning of Siberia against the northern margin of Laurentia (Sears & Price 2000; Pelechaty 1996; Hoffman 1991; Dalziel 1997; Condie & Rosen 1994; Frost et al. 1998). Therefore, we wish to address the following points in the manuscript that we feel are contentious: