The Small Circle (SC) tools analyse the stereographic tracks (small circles) followed by the
palaeomagnetic vectors during folding processes. Working with interfolding and synfolding
remagnetizations, the Small Circle Intersection (SCI) method allows finding the best solution
of grouping that should correspond with the remagnetization direction. Once this is known,
it is possible to determine the magnetization age as well as the degree of bed tilting at this
moment. The SC tools are based on some assumptions, among which the coaxiality between
the different deformation events is the one addressed in this work (i.e. absence of vertical
axis rotations, VARs, or differential horizontal axis rotations, dHARs). This assumption is
based on the necessity of knowing the rotation axis for folding after the acquisition of the
remagnetization, and SC tools consider the bedding strike as this axis, something that is
only accomplished under coaxial folding. In order to explore how non-coaxiality affects the
solutions derived from the SC methods, we first (i) identify the variables that control these
errors through simple models that only consider two theoretical palaeomagnetic sites, after
that it is possible (ii) to derive the mathematical relationships between them. Finally, we (iii)
simulate errors derived from the use of SC tools using a population of 30 palaeomagnetic sites
recreating different possible scenarios with VARs and dHARs in nature.
