Digitisation of the 1:100k scale geological map of Harare, Zimbabwe

This report accompanies the digitised version of the geological map of Harare, Zimbabwe Geological Survey (ZGS) Bulletin Series, 1:100 000, corresponding to ZGS Bulletin No. 94. Map digitisation was carried out following the standard workflow for BGS digital map compilation with the aim to produce a ‘like-for-like’ digital copy of the paper map for the ZGS. The digitised map was converted to a QGIS-compatible GeoPackage containing layers for bedrock boundaries (line features), faults (line features), bedrock geology (polygon features) and bedrock seeds (point features).
The GIS point, line and polygon features contain attribute tables with information corresponding to the map-face labels and the legend on the paper map. Similar to the BGS data model for digital geological maps, all bedrock units were assigned a LEX-RCS code, where the LEX-part of the code contains information about the name of a geological unit and where it sits within the lithostratigraphical and lithodemic hierarchy of formation, members, groups etc., and where the RCS-part of the code contains information about the lithological composition of the unit.
Some minor modifications to the geological map were required to ‘fit’ the paper map into the output digital data model. All changes were made with the goal to keep the digital map as close to the paper version as possible. Most of these changes are minor and inconsequential to the geological information, narrative and model represented by the map. The details of the key considerations during this process and the resulting differences between the paper and digital map are recorded in this report for future reference.