Baddeleyite U-Pb age of metadiabase near Key Harbour, Britt domain, Grenville Province, Ontario; Radiogenic age and isotopic studies: Report 14
Bibliographic record
Abstract
Many occurrences of metadiabase in the parautochthonous belt of the Grenville Province in Ontario have a geochemical signature indistinguishable from that of Sudbury diabase in the adjacent Superior and Southern provinces, and some bodies close to the Grenville Front are known to have the same ca. 1.24 Ga age. However, dating of baddeleyite in metadiabase with Sudbury-type chemistry from a small mass enclosed in orthogneiss near Key Harbour shows it to be at least 200 Maolder than Sudbury diabase, which casts doubt on the use of rock chemistry as a correlation tool for tracing the extent of Sudbury metadiabase within the parautochthon. Despite this, the common chemical signature of metadiabase of whatever age in the parautochthonous footwall of the allochthon boundary thrust zone serves as a distinction from the 1.17 1.15 Ga coronitic metagabbro in the hanging wall, the two being spatially mutually exclusive.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| 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) | 0.002 | 0.001 |
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".