A discussion on papers “Nature of a major tectonic discontinuity in the Svecofennian province of northern Sweden” by Rutland et al. (PR 112, 211–237, 2001) and “Age of deformation episodes in the Palaeoproterozoic domain of northern Sweden, and evidence for a pre-1.9 Ga crustal layer” by Rutland et al. (PR 112, 239–259, 2001)