Subordinate Structures – Considerations and Benefi ts

摘要

The structural models developed by exploration and mining geologists are most commonlyrnconcerned with the ‘main structures’ or key constituents that pertain to the associatedrnmineralisation. To this end, it is recognised that the geological and exploration models, which arerndeveloped, are essentially ‘fi t for task’ and the scale-related variances are not always realised atrnan early stage. In fact, in many cases anomalous intercepts along different trends and of variablernapparent continuity have often been neglected as ‘back scatter’ and not important.rnRecognition of the importance of subordinate structures as mineralising hosts suggests thatrnadditional opportunities exist outside the primary and main structures. History shows thatrnopportunities are often not realised where gold is hosted in orientations not parallel to thernpredominant trend of the schistosity, main fault or shear zone.rnAnother reason for the importance of subordinate structures can be understood from theirrnroles in a percolation network. Subordinate structures can access the large fl uid fl uxes providedrnby backbone elements, but, as dangling elements, they provide greater opportunities for goldrnprecipitation mechanisms and hence may constitute essential parts of the resource. Therefore, thernrole, understanding and consideration of the smaller-scale and orthogonal structures should bernconsidered during all facets of exploration, resource development, delineation and mining.