Extent, origin, and deposit-scale controls of the 1883 Ma Circum-Superior large igneous province, northern Manitoba, Ontario, Quebec, Nunavut and Labrador
Bibliographic record
Abstract
An update is presented on research in the setting and controls on Ni-Cu-PGE in the ca. 1883 Ma Circum-Superior belt, here with a specific focus on the Raglan belt of northern Quebec. A new stratigraphic interpretation indicates that the critical part of the stratigraphy is less imbricated by numerous thrusts than previously hypothesised and that the critical Povungnituk to Chukotat Group contact, i.e. the Raglan Horizon, is stratigraphic and not a regional thrust. This contact, along which hot komatiitic lavas flowed out over easily fusible graphitic mudstone of the Nuvilik Formation, is stitched together in a primary sense by thermo-mechanical erosion channels with some of the largest sulphide ore lenses hosted by the deepest lava channels that eroded down through Nuvilik sediments into footwall gab-bro sills. Precise U-Pb ages on these gabbro sills, and on slightly younger gabbro sills that intruded above the lower-most komatiite flows and ore lenses, bracket the mineralization to ca. 1882 Ma, an age that is identical to those of the Thompson deposits in Manitoba. The bulk of the sulphide ore formed during peak effusion rates of komatiitic lava during the onset of the overall magmatic event. This major magmatic event has (coeval) expressions at the scale of the entire Superior craton and its margins, suggesting a geodynamic setting of hot mantle upwelling and continental break-up rather than perfectly synchronized arc processes.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.003 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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".