HR: 10:35h
AN: GP41D-02    [PDF]
TI: A New Late Neoproterozoic and Early Cambrian Paleogeography in the True Polar Wander Paradigm
AU: * Raub, T D
EM: timothy.raub@yale.edu
AF: Yale University, Department of Geology and Geophysics, New Haven, CT 06511
AU: Evans, D A
EM: dai.evans@yale.edu
AF: Yale University, Department of Geology and Geophysics, New Haven, CT 06511
AU: Maloof, A C
EM: maloof@fas.harvard.edu
AF: Harvard University, Department of Earth and Planetary Sciences, Cambridge, MA 02138
AB: Seemingly anomalous paleomagnetic pole determinations from all continents during post-Cryogenian and early Cambrian time may reflect the governance of one (or a combination) of several nonuniformitarian geodynamic processes. Conceivable explanations for paleomagnetic pole dispersion over that duration include enhanced subordinate or predominant geocentric axial non-dipole geomagnetic fields; unexpected geocentric, non-axial dipole geomagnetic fields; a sustained regime (or multiple bursts) of true polar wander; and invocation of multiple, site-specific geological explanations for individual pole position differences. Time-sequence magnetostratigraphic data from appropriate sedimentary intervals may test among these possibilities. Both a new compilation of recently-reported and in-progress paleomagnetic poles determined from strata belonging to Laurentia, East Gondwanaland, Siberia, and Avalonia and also an inclusive review of the paleomagnetic database from other continents are consistent with first-order expectations of a standard plate-tectonic world undergoing nonuniformitarian oscillatory true polar wander. In this compilation, superposition of APWP swaths from all continental fragments defines discrete paleogeographies permitted in the true polar wander paradigm. These reconstructions provide critical constraints on models concerning global climate and biological change during the Terminal Neoproterozoic.
DE: 1520 Magnetostratigraphy
DE: 1525 Paleomagnetism applied to tectonics (regional, global)
DE: 1527 Paleomagnetism applied to geologic processes
DE: 1532 Reference fields (regional, global)
DE: 1560 Time variations--secular and long term
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2003 Fall Meeting