Value of mineral deposits associated with mafic and ultramafic magmatism: Implications for exploration strategies
Bibliographic record
Abstract
Magmatic ore deposits associated with ultramafic and mafic magmatism (MODUM) include nickel sulfide deposits that are locally enriched in copper, cobalt, platinum group elements and gold, a diverse range in platinum group element deposit types, oxide- and silicate-related nickel–cobalt laterite deposits formed by weathering of ultramafic bodies, and massive and stratiform accumulations of chromite, ilmenite and vanadium-bearing magnetite. Magmatic ore deposits associated with ultramafic and mafic rocks span most of earth's history and are well represented on all continents, and in all climatic zones and physiographic regions. Currently, these deposits are estimated to account for approximately 7% of the total value of annual global metal and mineral mining. They include the world's greatest concentration of metals — the Bushveld Complex, which has an estimated total metal endowment value, representing past production and current reserves and resources, of $US 3.6 trillion. Recent trends in exploration spending for mafic to ultramafic magmatic ore deposits compared to commodity market size and production value indicate a significant under-investment in exploration for magmatic chromite, ilmenite–vanadium and polymetallic disseminated copper–nickel–platinum group element sulfide deposits. Historically, exploration of mafic to ultramafic magmatic belts has commonly involved a narrow range of deposit models, geological environments and exploration methods. A value-based and more holistic approach to exploration for mafic to ultramafic magmatic ore deposits is proposed that captures a larger range of known mineralization styles, settings and commodities. A focus on high-value deposits providing excellent operating margins and long mine life is recommended as a starting point for new programs. However, by recognizing the full range of possible mineralization styles and understanding mineral economic thresholds, future explorers can expand the search area and methodology and increase the probability of discoveries that create value. Assuming that commodity prices continue to rise with declining average grades, current global resources hosted by mafic to ultramafic magmatic ore deposits are adequate to meet global demand for nickel, platinum group elements (PGE), chromium and vanadium for many decades to come. Despite this, the high net smelter return (NSR) value of many types of MODUM deposits provides ongoing economic motivation for both greenfields and brownfields exploration in these strategically important deposits. Furthermore, the large range in producer costs for key MODUM commodities such as nickel, copper and PGE provides significant opportunities for new projects to displace existing, higher-cost operations on the industry cost curve. The known clustering of high-value deposits within discrete magmatic belts (e.g., nickel sulfide and nickel laterite deposits) is an additional motivation for exploration investment as it allows exploration to focus early in areas of higher mineral potential. Additional incentives for MODUM exploration include the cumulative size and maturity of MODUM commodities that reduce investment risk and thereby appeal to junior explorers, mid-cap explorers and developers and major, multi-national mining companies. The economies of scales that were successfully applied to mining of large porphyry copper deposits for many decades could have a similar positive impact on a large number of advanced MODUM projects, especially polymetallic sulfide deposits capable of generating high value concentrates having significant base metal and precious metal contents.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.010 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.004 | 0.003 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".