40 Ar-39 Ar geochemical investigations in the central Hearne domain, western Churchill Province, Nunavut: a progress report; Radiogenic age and isotopic studies: Report 14
Bibliographic record
Abstract
The western Churchill Province of the northwest Canadian Shield was originally defined on the basis of wide- spread, Proterozoic K-Ar ages, but early mapping in conjunction with sparse, old K-Ar ages indicated that it con- tained preserved remnants of Archean supracrustal and granitoid rocks. A reconnaissance 40 Ar-39 Ar thermochronological investigation of a segment of crust lying along a north-northwest-trending transect from Kaminak Lake (central Hearne domain) in the south to Yathkyed Lake (northern Hearne domain) in the northwest, indicates that the Archean supracrustal belts preserve primary Archean igneous and metamorphic cooling ages for hornblende, but biotite ages were reset in the Proterozoic. The domain lying between the two supracrustal belts yielded Proterozoic ages for all dated minerals. The resetting of the 40 Ar-39 Ar systematics is attributed tolarge-scale thermal overprinting during Hudsonian deformation and magmatism at ca. 1830-1810 Ma and subse- quent slow cooling. Local evidence for ca. 1750 Maresetting of mica ages exists, but no unequivocal evidence for a ca. 1900 Ma tectonothermal event can be discerned in the 40 Ar-39 Ar thermochronological data.
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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 | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.003 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 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".