This amalgamated layer is made up of several layers. These are: Tailings Licences - Expired (tlhst), Gold Mining Licences - Expired (gmlhst), Mineral Leases - Expired (milhst), Expired Extractive Industry Work Authorities (ewahst), Expired Mining Licences (minhst), Exploration Licences - Not Active (1973+) (elhist), Exploration Licence Moratorium Period Areas (mp), Proposed Work Authorities (wap), Mining Licences (min), Extractive Industry Work Authorities (ewa), Exploration Licences (el). The boundaries are derived from a combination of entering graticular boundaries (exact AMG co-ordinates) and digitizing along areas of land status (Minerals and Petroleum version of landmmt100) which are unable to be mined or explored. Refer to the Mineral Resources Development Act (MRDA) for more detail.