The structural models developed by exploration and mining geologists are most commonly concerned with the ‘main structures’ or key constituents that pertain to the associated mineralisation. To this end, it is recognised that the geological and exploration models, which are developed, are essentially ‘fit for task’ and the scale-related variances are not always realised at an early stage. In fact, in many cases anomalous intercepts along different trends and of variable apparent continuity have often been neglected as ‘back scatter’ and not important.
Recognition of the importance of subordinate structures as mineralising hosts suggests that additional opportunities exist outside the primary and main structures. History shows that opportunities are often not realised where gold is hosted in orientations not parallel to the predominant trend of the schistosity, main fault or shear zone.
reason for the importance of subordinate structures can be understood from their
roles in a percolation network. Subordinate structures can access the large
fluid fluxes provided by backbone elements, but, as dangling elements, they
provide greater opportunities for gold precipitation mechanisms and hence may
constitute essential parts of the resource. Therefore, the role, understanding
and consideration of the smaller-scale and orthogonal structures should be
considered during all facets of exploration, resource development, delineation
Nugus, M J, Blenkinsop, T G, Doyle, M G and Nichols, S,
2011. Subordinate structures – considerations and benefits, in Proceedings Eighth
International Mining Geology Conference 2011,
143-152 (The Australasian
Institute of Mining and Metallurgy: Melbourne).