Envision designing a drilling campaign with only part of the story – sounds familiar, right? That was exactly the challenge our client’s IOCG exploration team faced Monteiro (2014). Please note that, by Vektore’s Data Anonymization (DA) protocols, certain details about the deposit have been withheld or generalized to protect our clients.
Although we had geophysical data, much of it was overwhelmed by a strong and dispersed magnetic signature, making it ineffective for pinpointing new targets, particularly those with complex geometries. Copper-gold soil anomalies suggested a possible extension of a known IOCG deposit, leading us to design a drilling program to test a horizontal mineralization model across a recently acquired tenement. However, at the time, our core orientation set was limited, and crucial structural information was not extracted during the first round of logging. This meant we lacked insight into the internal features of the stratabound-style mineralization, leaving us uninformed of the true grade distribution, structural controls, and the existence of potential ore shoots. As a result, we were working with an incomplete picture, one that could significantly impact on our client’s drilling decisions.
We were tasked with reprocessing the available oriented core within the known mineralization, focusing on extracting structural features related to both mineralization and deposit architecture. Our goal was to assess whether the prescribed drilling pattern was appropriate, process the data, and define the internal structure of the mineralized system. Since grade distribution and structural features often share geometric patterns (Monteiro, 1996; Monteiro, 2004), we set out to identify and validate these relationships.
Our toolbox included the Structural Vectoring® Log, used to systematically capture and classify structural features observed in core, alongside with vPCDTM (Vektore – point cloud deletion, 2012). Together, these methods enabled us to query, filter, and assign grade values to structural features, providing an initial assessment of grade-structure correlations. While our process involved stepwise deletion of lower-grade samples, our primary objective was to remove boreholes that did not align with mineralization geometry to refine the mineral intersection geometry (MIG). Further insights on mineralization- and architecture-related structural features can be found here: Exploration Success … What’s the Drill?
Over several months, we conducted detailed structural logging, focusing first on characterizing the structural controls on the mineralization system. This included sulphide lineations (see Figure 1), as well as the shape orientation of minerals and inclusions within sulphide stringers. In addition, we gave particular attention to mineralization-related structural features. To gain a better understanding of the geological framework, we also recorded architectural-related structural features, capturing the geometry in which mineralization was embedded. Our goal was to monitor the orientation distribution of these structural features under the working hypothesis that grades and lineations were spatially correlated. If validated, this relationship could be leveraged to optimize our drilling pattern and improve targeting efficiency.
As a result of the exploration team’s bold approach, the decision to revise the prescribed drilling pattern – guided by our structural analysis and deliverables – led to the discovery of a new Breccia Ore zone, returning approximately 95 Mt of copper-gold ore at 0.7% CuEq of inferred resources (communication from client). The deposit remains open to the north, and our work also identified additional ore shoot orientations that require further verification.
Ore shoot spatial orientations and their locations were determined, validating the hypothesis that mineralization-related structural features are directly linked to grade distribution (see Figure 2 and Figure 3). This structural insight also explains the bulls-eye anomaly in soil geochemistry, which aligns with the projection of north-dipping ore shoots (see Figure 4)
The Value of Information (VoI – Lawie, 2024 and Gillis at al., 2024), which is the estimated worth of acquiring additional knowledge before making critical decisions, was clearly demonstrated through our work, significantly enhancing Orebody Knowledge (OBK – Maptek, 2018). By integrating newly gathered structural data, particularly from oriented core logging, our team gained a far clearer perspective on the geometry and continuity of the deposit, leading to the recognition of inclined ore shoots where none had previously been identified. This deeper understanding exemplifies the core principle of OBK, where every insight into a deposit’s architecture refines exploration strategies, reduces geological uncertainty, and enhances economic decision-making.
Through the application of Structural Vectoring, the prescribed drilling pattern was revised, allowing for the verification of grade distribution data and the validation of its relationship with mineralization-related structural features. This refinement directly influenced mineralization continuity, ensuring a more data-driven and geologically informed exploration strategy. The recognition of ore shoots introduced the possibility of underground mining, challenging the initial assumption that open-pit exploitation was the only viable option. This shift exemplifies the power of OBK-driven decision-making, where understanding the internal architecture of a deposit enables more efficient, cost-effective, and sustainable resource extraction. The VoI in this case is evident – not only did it reduce geological uncertainty, but it also unveiled an entirely new economic pathway for resource development. Furthermore, these findings extend beyond this single deposit. Other IOCG sites in the region could benefit from this enhanced Orebody Knowledge, refining their exploration models, reducing risk, and improving drill targeting efficiency. Armed with such detailed structural knowledge, we can design more precisely drilling campaigns, model resources more accurately, and make better-informed decisions that directly shape our approach to discovering and developing IOCG deposits and other deposit types.
This case study exemplifies how high-value geological information transforms decision-making, optimizes resource strategies, and ultimately increases financial and operational efficiency. Investing in a VoI-driven approach to Orebody Knowledge is not just about collecting data – it’s about empowering smarter, more profitable decisions that maximize resource potential.
What if your best target is still hidden – this discovery was possible because we challenged assumptions and let geology lead the way. What’s your experience with structural geology in mineral exploration? What are your thoughts on this approach? Have you faced similar challenges? Let’s discuss!
Gillis, A., Steen, J., Dunbar, S. and Nordenflycht, A. (2024) What causes mining asset impairments? Resources Policy 90, pg 1-10.
Lawie, D. (2024) Valuating Ore Body Knowledge – The Financial Keystone for Mining Success in: Geohug podcast – https://www.youtube.com/watch?v=IFxtRdoVE6c
Maptek. (2018). Maptek Roy Hill smart mining partnership. Retrieved from:
https://www.maptek.com/forge/september_2018/roy_hill_smart_mining_partnership/
Monteiro, R. N. (1996). Gold Mineralization at Ouro Fino Mine, Brazil (Doctoral dissertation). University of Western Ontario, London, Canada.
Monteiro, R. N., Fyfe, W. S., & Chemale, F. Jr. (2004). The impact of the linkage between grade distribution and petrofabric on the understanding of structurally controlled mineral deposits: Ouro Fino Gold Mine, Brazil. Journal of Structural Geology, 26(6), 1195–1214.
Monteiro, R. N. (2014) Structural Controls of Mineral Deposits …. How to Get it! SIMEXMIN 2014, 39 slides
Vektore (2012) Point Cloud Deletion (vPCDTM) – Standard Operating Procedure.