Abstract Economically viable concentrations of mineral resources are uncommon among the predominantly silicate-dominated rocks in Earth’s crust. Most ore deposits that were mined in the past or are currently being extracted were found at or near Earth’s surface, often serendipitously. To meet the future demand for mineral resources, exploration success hinges on identifying targets at depth, which, on the one hand, requires advances in detection and interpretation techniques for geophysical and geochemical data. On the other hand, however, our knowledge of the chain of events that lead to ore deposit formation is limited. As geoscience embraces an integrated Earth systems approach, considering the geodynamic context of ore deposits can provide a step change in understanding why, how, when and where geological systems become ore-forming systems. Contributions to this volume address the future resources challenge by: (i) applying advanced microscale geochemical detection and characterization methods; (ii) introducing more rigorous 3D Earth models; (iii) exploring critical behaviour and coupled processes; (iv) evaluating the role of geodynamic and tectonic setting; and (v) applying 3D structural models to characterize specific ore-forming systems.

Abstract Epithermal veins and breccias at the Kainantu gold–copper deposit in Papua New Guinea, host gold mineralization in NW–SE steeply dipping lodes. The lodes are parallel to a pre-mineralization dextral strike-slip shear-zone network, which is itself parallel in places to an early greenschist-facies cleavage in basement schists. The cleavage, shear zone and veins are all cut by dextral strike-slip faults. High Au grades correlate with areas of obliquity between the shear-zone fabrics and the cleavage, and plunge at approximately 40° SE in the plane of the lodes – coincident with minor fold axes related to a crenulation cleavage in the basement rocks. This clear structural history shows that gold mineralization was confined to a particular late structural event, but lode geometry was influenced by all previous structures, as well as being displaced by post-mineralization faulting. The north–south shortening recorded through most of the tectonic history can be related to Tertiary convergence along the major plate boundary located approximately 15 km north of the mine. However, mineralization occurred under a different tectonic regime from the current north–south convergence, when there was a change of tectonics between 9 and 6 Ma, possibly related to delamination.

Abstract A unified system of collecting structural data from drill core is proposed. The system encompasses planes and planar fabrics, lineations, fold hinges and hinge surfaces, faults and shear zones, vorticity vectors, shear directions and shear senses. The system is based on standard measurements of angles in the reference frame of the core (α and β angles), which are easily carried out by means of core protractors or templates. The methods for dealing with folds and kinematic analysis of shear zones have not been described previously, but they follow logically from the standard methods for dealing with planes and lines.