Thermoluminescence Dating of Late Pleistocene Sediments, St. Lawrence Lowland, Québec
Bibliographic record
Abstract
This paper presents the results of a thermoluminescence (TL) dating program applied to waterlaid sediments of Late Pleistocene age, collected in the central St. Lawrence Lowland, in eastern Canada. The apparent TL ages were obtained using a partial bleach method (R-Gamma) in which the TL from light-sensitive traps is separated from the total TL. Fluvial (modern), marine (late-glacial) lacustrine (interstadial) and glacio-lacustrine (stadial) sediments yielded apparent ages ranging from 4 to 135 ka, and in general, these ages agreed with available stratigraphic evidence. Whilst testing the zeroing assumption, apparent TL ages obtained from modern fluvial and late glacial sediments suggest that laboratory overbleaching or insufficient natural bleaching may result in over-estimation of the apparent TL ages by 4-5 ka. All samples display anomalous fading, a problem that can be overcome by introducing a three month delay between artificial irradiation and glowing. Future research should focus on sediments for which the age as well as the sedimentology are well documented, such as the late glacial Champlain Sea sediments.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| 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) | 0.001 | 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".