Comment on “Influence of data filters on the position and precision of
paleomagnetic poles: what is the optimal sampling strategy? ” by
Gerritsen et al. (2022).
In a recent paper, Gerritsen et al. (2022) propose to modify the
well-accepted sampling strategy in paleomagnetism by collecting more
single-sample sites. They also argue that the paleomagnetic community
commonly applies a loosely defined set of quantitative data filters and
that there is no need for an expert-eye to analyze and interpret
paleomagnetic data. Many paleomagnetists will disagree with these claims
as paleomagnetic methods provide very robust results at the site level
when the study is done with sufficient rigor. As stated in Gerritsen et
al. (2022) they deliberately kept directions that an experienced
paleomagnetist would likely immediately discard as unreliable. Can we
really draw conclusions from such an approach to paleomagnetism? The
strategy proposed by Gerritsen et al. (2022) has serious drawbacks well
illustrated by the datasets from Turkey (van Hinsbergen et al., 2010),
Mongolia (van Hinsbergen et al., 2008), Norway (Haldan et al., 2014),
and Antarctica (Asefaw et al., 2021) used by Gerritsen et al. (2022).
The main objective of this comment is to support standard methods
(Butler, 1992; Tauxe et al., 2018) for a well-defined determination of
the paleomagnetic direction per site based on the sampling of several
samples per site.