Bibliographic record
Abstract
Experimental data on the solubility of Pt and Pd under various hydrothermal conditions suggest that transport and deposition of high levels of these elements could occur in several geological environments without the need for mafic magmatic fluids or heat. In intracratonic rift environments, oxidized brines generated by surface evaporation and/or halite dissolution circulate to depth through a preponderance of oxidized lithologies and precipitate Pt and Pd in association with U and Au (unconformity-type U deposits) or Cu (sediment-hosted Cu deposits). Pt and Pd are likely to transported as chloride complexes in such oxidised brines. The best known product of this process is the Coronation Hill deposit in Australia. In deformed passive margin sequences rich in carbonaceous and pyritic metasedimentary rocks, hydrothermal fluids are most likely to be reduced and have elevated sulfur content. Under these conditions Pt and Pd would be transported as bisulfide complexes. Potentially economic levels of Pt and Pd have been reported in numerous orogenic gold deposits of the former Soviet Union (notably the Sukhoi Log deposit) and in sediment-hosted Ni and Mo deposits of southern China and north-western Canada. Oxidized low-salinity waters in surface environments buffered by atmospheric oxygen could also lead to mobility of Pt and Pd as hydroxyl complexes. Anomalous but subeconomic levels of Pt and Pd have been reported in lowtemperature hydrothermally altered rocks of the Semail ophiolite and in laterite developed on ophiolitic rocks. These examples suggest that high grades of Pt and Pd occur in a wide range of deposit types, although there is clearly a problem in some cases with quality of analysis. A crucial question is whether there is the potential for both high grades and large tonnages of Pt and/or Pd-bearing ore in these settings. This question can be answered in part by routine analysis for Pt and Pd by exploration geologists and by further research into transport and depositional processes. The hydrothermal Ni-Cu-PGE sulfide ore of the Fortaleza de Minas deposit, Brazil C.M. ALMEIDA AND G.R. OLIVO
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".