The more detailed geologic map \citep{MacielFilho1990} was based on the same topographic maps used to produce the soil map of \citet{MiguelEtAl2012}. It also includes the location of Quaternary sedimentary deposits. The main weakness of this map is that it does not cover the Northern sector of the study area – note the horizontal discontinuity of mapping units BT - Botucatu Formation, and SG-I - Inferior Sequence of the Serra Geral Formation.

We understand that, compared to the map of \citet{GasparettoEtAl1988}, the more detailed map of \citep{MacielFilho1990} would not include significant changes in the spatial distribution of mapping unit SG-S (Superior Sequence of the Serra Geral Formation, depicted in yellow). Significant changes could be expected in the small area in the Northern sector which is occupied by mapping units BT and SG-I. Because only \(n=\) 13 out of \(n=\) 350 point soil observations fall in this region, we decided that the currently best alternative is to fill the gap of the map of \citep{MacielFilho1990} with data from the map of \citet{GasparettoEtAl1988}.