Petrogenesis of the Mesoarchaean Stella layered intrusion, South Africa: implications for the origin of PGE reefs in the upper portion of layered intrusions
Bibliographic record
Abstract
Abstract The ~3033 Ma Stella layered intrusion is hosted by supracrustal rocks of the Kraaipan–Madibe greenstone terrane, South Africa. The studied portion of the intrusion consists mainly of magnetite leucogabbro and magnetite anorthosite, as well as several massive magnetite layers. The intrusion hosts a laterally continuous, ~60-m-thick, PGE mineralized interval, with total resources amounting to 108t Pt + Pd + Au, constituting one of the oldest known PGE reef-style mineralizations on Earth. The richest reef, with a grade of 4.4 ppm Pt+Pd over a width of 5–8 m, occurs in semi-massive magnetitite. It is suggested that the mineralized oxide and silicate layers formed through a combination of primary magmatic, late magmatic, and hydrothermal processes, including granular flow and phase sorting of a magnetite- and sulfide-bearing gabbroic crystal mush that crystallized from a tholeiitic basalt, as well as remobilization of S and metals by late magmatic and hydrothermal fluids that led to crystallization of platinum-group minerals.
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 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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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 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".