SHRIMP U-Pb detrital zircon geochronology of enigmatic Neoarchean-Paleoproterozoic sedimentary rocks of the central western Churchill Province, Nunavut; Radiogenic Age and Isotopic Studies: Report 15
Bibliographic record
Abstract
The dominant U-Pb age of detrital zircons in three stratigraphically enigmatic sandstone units from the central part of the western Churchill Province ranges from 2730.2660 Ma, demonstrating mainly local provenance from underlying volcanoplutonic belts and that the units are younger than ca. 2.66 Ga. These ages are inconclusive for resolving the late Neoarchean versus early Paleoproterozoic depositional age of the sandstone units. A specimen from the Montgomery Group represents either a molasse developed late in the history of the underlying Neoarchean Henik-Kaminak-Tavani greenstone belt or an early Paleoproterozoic precursor to the Hurwitz Group. Younger grains in a specimen from the Spi Group support the interpretation that it represents a ca. 2450 Ma rift deposit, coeval with the Kaminak mafic magmatic event. A prominent ca. 2680 Ma detrital zircon mode in a specimen of quartzite from the Happy lake area and its aluminous composition are consistent with it being part of the lower Hurwitz Group.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 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".