A reviewer has questioned whether the model of

A reviewer has questioned whether the model of sorting of crystal mushes that PR957 slump turbulently along the sidewall and bottom of the chamber is consistent with the large scale continuity of PGE reefs such as the Merensky Reef and the MSZ. Firstly, we note that the data accumulating from the increasing number of open pit operations of the reefs as well as careful observations of underground developments indicate that the reefs are far less continuous than generally perceived (Maier et al., 2013a and Latypov et al., 2015). The Merensky Reef has abundant potholes, sill-like apophyses, and shows significant lateral and down-dip variation in thickness and stratigraphic disposition. The frequency of these features has been underestimated from drill core studies. Secondly, the envisaged sorting process is not turbulent and chaotic, but analogous to kinetic sieving (the Brazil nut effect) which leads to concentration of the small and relatively dense particles towards the base of the reservoir, but broad preservation of the original stratification.