Constraints from apatite fission track analysis1
Bibliographic record
Abstract
The results of Apatite Fission Track (AFT) analysis for Cretaceous, Paleozoic and Precambrian borehole samples along two major transects through the Western Canada Sedimentary Basin (WCSB) are reviewed here. The northern transect crosses the Peace River Arch (PRA) and extends approximately 700 km from northeast British Columbia to the Alberta-Saskatchewan border northeast of Fort McMurray; the southern transect through central Alberta extends from the edge of the disturbed belt near Rocky Mountain House to the Alberta-Saskatchewan border north of Cold Lake. Sample AFT age and length data show a wide range in the degree of annealing due to the complicated thermal history of the basin and require interpretation through use of a quantitative model. A temperature-dependent fission track annealing model and a controlled random search technique were used to determine sample thermal histories from mea-sured AFT parameters. Many of the Cretaceous samples along the PRA transect appear to have been deposited with effectively zero fission track age, implying a contemporaneous volcanic source for the apatite or rapid exhumation of the source area. Fully annealed samples yield an estimate of 60 Ma for the time of maximum temperature and inferred maximum burial. Maximum AFT paleotemperatures and maximum paleoburial depths (estimated from coal moisture data) were used to estimate paleogeothermal gradient distributions at 60 Ma. For the central Alberta transect, paleogeothermal gradients
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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 | 0.006 | 0.013 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".