DETRITAL PLATINUM-GROUP MINERALS IN RIVERS DRAINING THE EASTERN BUSHVELD COMPLEX, SOUTH AFRICA
Bibliographic record
Abstract
During field work in the eastern Bushveld, more than 6000 grains of platinum-group minerals (PGM) were recovered from alluvial sediments by panning on the farm Maandagshoek and its environs. The grains were investigated by reflected-light microscopy, scanning electron microscopy and electron-microprobe analysis. More than 40 different species of PGM were found. Monophase grains of Pt–Fe alloy are the most common, followed by sperrylite, cooperite, braggite, isomertieite or mertieite I, stibiopalladinite or mertieite II, and Ru–Os–Ir–Pt alloy. Polyphase grains comprise various combinations of one or two of the aforementioned PGM and laurite, sulfides and arsenides of Rh and Pd, and a wide variety of Pd-dominant compounds with As, Sb, Te, Fe, Sn, Pb and Hg, some of which are previously unreported from the Bushveld Complex or even unnamed species. The individual PGM grains show various degrees of attrition. They are mostly unaltered, but the assemblage also contains partly to severely altered grains. The different states of preservation probably point to long-lived, continuous accumulation of the PGM by sedimentological processes. The large grain-sizes of the PGM in the placers (40 μm to 1.6 mm) compared to those of PGM in the Merensky Reef and the UG–2 (generally
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 teacher head, 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".