TY - JOUR
T1 - On Pole Position
T2 - Causes of Dispersion of the Paleomagnetic Poles Behind Apparent Polar Wander Paths
AU - Vaes, Bram
AU - Gallo, Leandro C.
AU - van Hinsbergen, Douwe J.J.
N1 - Funding Information:
BV and DJJvH acknowledge NWO Vici Grant 865.17.001. We thank Lisa Tauxe, Nick Swanson‐Hysell and associate editor Daniel Pastor‐Galán for their constructive feedback and helpful suggestions. We thank Cor Langereis and David Heslop for discussion. LCG has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Skłodowska‐Curie Grant Agreement No. 101025975.
Funding Information:
BV and DJJvH acknowledge NWO Vici Grant 865.17.001. We thank Lisa Tauxe, Nick Swanson-Hysell and associate editor Daniel Pastor-Gal?n for their constructive feedback and helpful suggestions. We thank Cor Langereis and David Heslop for discussion. LCG has received funding from the European Union's Horizon 2020 research and innovation program under the Marie Sk?odowska-Curie Grant Agreement No. 101025975.
Publisher Copyright:
© 2022. The Authors.
PY - 2022/4
Y1 - 2022/4
N2 - Paleomagnetic poles used to compute apparent polar wander paths (APWPs) are strongly dispersed, which was recently shown to cause a large fraction (>50%) of these poles to be statistically distinct from the APWP to which they contributed, suggesting that current statistical approaches overestimate paleomagnetic resolution. Here, we analyze why coeval paleopoles are so dispersed, using the paleopoles behind the most recent global APWP and a compilation of paleomagnetic data obtained from <10 Ma volcanic rocks (PSV10). We find that paleopoles derived from sedimentary rocks, or from data sets underrepresenting paleosecular variation (PSV), are more dispersed and more frequently displaced. We show that paleopoles based on a smaller number of paleomagnetic sites are more dispersed than poles based on larger data sets, revealing that the degree to which PSV is averaged is an important contributor to the pole dispersion. We identify as a fundamental problem, however, that the number of sites used to calculate a paleopole, and thus the dispersion of coeval paleopoles, is essentially arbitrary. We therefore explore a different approach in which reference poles of APWPs are calculated from site-level data instead of paleopoles, thereby assigning larger weight to larger data sets. We introduce a bootstrap-based method for comparing a collection of paleomagnetic data with a reference data set on the same hierarchical level, whereby the uncertainty is weighted against the number of paleomagnetic sites. Finally, our study highlights that demonstrating smaller tectonic displacements requires larger paleomagnetic data sets, and that such data sets can strongly improve future APWPs.
AB - Paleomagnetic poles used to compute apparent polar wander paths (APWPs) are strongly dispersed, which was recently shown to cause a large fraction (>50%) of these poles to be statistically distinct from the APWP to which they contributed, suggesting that current statistical approaches overestimate paleomagnetic resolution. Here, we analyze why coeval paleopoles are so dispersed, using the paleopoles behind the most recent global APWP and a compilation of paleomagnetic data obtained from <10 Ma volcanic rocks (PSV10). We find that paleopoles derived from sedimentary rocks, or from data sets underrepresenting paleosecular variation (PSV), are more dispersed and more frequently displaced. We show that paleopoles based on a smaller number of paleomagnetic sites are more dispersed than poles based on larger data sets, revealing that the degree to which PSV is averaged is an important contributor to the pole dispersion. We identify as a fundamental problem, however, that the number of sites used to calculate a paleopole, and thus the dispersion of coeval paleopoles, is essentially arbitrary. We therefore explore a different approach in which reference poles of APWPs are calculated from site-level data instead of paleopoles, thereby assigning larger weight to larger data sets. We introduce a bootstrap-based method for comparing a collection of paleomagnetic data with a reference data set on the same hierarchical level, whereby the uncertainty is weighted against the number of paleomagnetic sites. Finally, our study highlights that demonstrating smaller tectonic displacements requires larger paleomagnetic data sets, and that such data sets can strongly improve future APWPs.
KW - apparent polar wander path
KW - paleomagnetic pole
KW - paleomagnetism
KW - paleosecular variation
UR - http://www.scopus.com/inward/record.url?scp=85128704324&partnerID=8YFLogxK
U2 - 10.1029/2022JB023953
DO - 10.1029/2022JB023953
M3 - Article
AN - SCOPUS:85128704324
SN - 2169-9313
VL - 127
JO - Journal of Geophysical Research: Solid Earth
JF - Journal of Geophysical Research: Solid Earth
IS - 4
M1 - e2022JB023953
ER -