Structural study of Sudbury breccia and sulphide veins, Levack embayment, North Range of the Sudbury structure, Ontario
Bibliographic record
Abstract
The ca. 2.7 Ga Levack gneiss complex underlies the Levack embayment and northern part of the Sudbury structure. Sudbury breccia, a unit of centimetre- to metre-scale clasts and blocks in a fine-grained to aphanitic matrix, occurs as veinlets, veins, and irregular, disconnected, metre-wide massive bodies within wide breccia zones that cut the Levack gneiss complex. Sudbury breccia veins show no systematic orientations or displacements. Conjugate sets of chalcopyrite veins hosted by Sudbury breccia, and veins filled by hydrothermal minerals at the Barnet showing, were emplaced in tensile fractures perpendicular to the gneissic foliation. Observations suggest that the Sudbury breccia originated by in situ brecciation during propagation of impact shock waves, rather than by milling and friction melting along superfaults during collapse of impact crater walls. Sulphide veins were emplaced in tensile fractures that propagated perpendicular to gneissic foliation and coincided with hydrothermal activity.
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 | 0.002 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 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 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".