HR: 1340h
AN: GP43A-0921    [Abstracts]
TI: Paleosecular variation during the PCRS based on a new database of sedimentary and volcanic records
AU: * Haldan, M M
EM: haldan@geo.uu.nl
AF: Paleomagnetic Laboratory 'Fort Hoofddijk', Utrecht University, Budapestlaan 17, Utrecht, 3584 CD, Netherlands
AU: Langereis, C G
EM: langer@geo.uu.nl
AF: Paleomagnetic Laboratory 'Fort Hoofddijk', Utrecht University, Budapestlaan 17, Utrecht, 3584 CD, Netherlands
AU: Evans, M E
EM: evans@phys.ualberta.ca
AF: Avadh Bhatia Physics Laboratory, University of Alberta, Alberta, Edmonton, T6G 2J1, Canada
AB: We present a paleosecular variation study using a generalised global paleomagnetic sedimentary and volcanic database. We made use of all available (and suitable) - published and some new- sedimentary and volcanic paleomagnetic records corresponding to the Permo-Carboniferous Reversed Superchron (PCRS) interval to reanalyse all data. We focused on records with a sufficient number of samples, and acquired – whenever possible – the original data, or – as a second choice - parametrised published site means. Analysis of these paleomagnetic data in terms of latitude variation of the scatter of the virtual geomagnetic poles (VGPs) suggests that careful data selection is required and that some of the older studies may need to be redone using more modern methods, both in terms of sampling and laboratory treatment. In addition, high (southern and especially northern hemisphere) latitudes are notably lacking in published records. The transitional data is removed using a variable VGP cut-off angle which varies with latitude. We use also our extended sedimentary records from Permian red beds from the Lodève and Dôme de Barrot basins (S. France), a new detailed paleomagnetic study of the Permian volcanics in the Oslo graben (Norway), as well as new data from Carboniferous-Permian sediments from the Donbas basin (Ukraine). We compare our results with those from published paleosecular variation models and with recent (re)analyses of VGP scatter during different periods of the geological archive.
DE: 1522 Paleomagnetic secular variation
DE: 1560 Time variations: secular and longer
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Fall Meeting