Synthetic apparent polar wander (APW) paths for North America, South America, Eurasia, India, Central Africa, Australia and Antarctica for the last 200 Myr are proposed. Computation of these APW paths is based upon the latest version (4.5a) of the Global Paleomagnetic Database (GPMDB), a revised global plate tectonic model since the Early Jurassic, and a new technique for generating smoothed APW paths. The smoothing technique includes the following steps: (1) pre-selection of palaeopoles, including pre-filtering parameters (number of sites, number of samples per site, 95 per cent confidence circle about mean direction, cleaning procedure, and time uncertainty); (2) generation of palaeolatitude and declination plots for a reference site on each continent that combines palaeopoles via a global plate tectonic circuit; (3) independent spline regression analyses of the palaeolatitude and declination plots; (4) removal of palaeolatitude or declination data that deviate by more than 10◦ from the regression curves (post-filtering process); (5) generation of synthetic APW paths from the resulting palaeolatitude and declination plots. These synthetic APW paths are then rotated into African coordinates to determine the best-fit APW path and a global palaeomagnetic reference frame. Four representative plate tectonic reconstructions and global plate velocity fields are presented for the three time intervals that correspond to globally synchronous changes in plate motion.
Apparent polar wander paths for the major continents (200 Ma - Present Day): A paleomagnetic reference frame for global plate tectonic reconstructions
SCHETTINO, Antonio;
2005-01-01
Abstract
Synthetic apparent polar wander (APW) paths for North America, South America, Eurasia, India, Central Africa, Australia and Antarctica for the last 200 Myr are proposed. Computation of these APW paths is based upon the latest version (4.5a) of the Global Paleomagnetic Database (GPMDB), a revised global plate tectonic model since the Early Jurassic, and a new technique for generating smoothed APW paths. The smoothing technique includes the following steps: (1) pre-selection of palaeopoles, including pre-filtering parameters (number of sites, number of samples per site, 95 per cent confidence circle about mean direction, cleaning procedure, and time uncertainty); (2) generation of palaeolatitude and declination plots for a reference site on each continent that combines palaeopoles via a global plate tectonic circuit; (3) independent spline regression analyses of the palaeolatitude and declination plots; (4) removal of palaeolatitude or declination data that deviate by more than 10◦ from the regression curves (post-filtering process); (5) generation of synthetic APW paths from the resulting palaeolatitude and declination plots. These synthetic APW paths are then rotated into African coordinates to determine the best-fit APW path and a global palaeomagnetic reference frame. Four representative plate tectonic reconstructions and global plate velocity fields are presented for the three time intervals that correspond to globally synchronous changes in plate motion.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.