Effet réservoir sur les âges 14C de la Mer de Champlain à la transition Pléistocène-Holocène : révision de la chronologie de la déglaciation au Québec méridional
Bibliographic record
Abstract
L’âge de macrorestes de plantes terricoles et une extrapolation fondée sur le pollen des sédiments sous-jacents à la date basale du lac postglaciaire de Hemlock Carr (243 m), au mont Saint-Hilaire, montrent que la déglaciation locale y est survenue vers 11 250 ans 14C BP (13,3-13,1 ka BP). La datation croisée entre de tels macrorestes (10 510 ± 60 ans 14C BP) et des coquilles de sédiments marins (~12 200 ans 14C BP) piégés au fond du lac Hertel (169 m), voisin, affiche un écart d’environ 1700 ans 14C attribué principalement à un vieillissement par les eaux de surface de la Mer de Champlain. Au lac Hertel, l’extrapolation chronologique fondée sur le pollen situe l’invasion marine locale vers 10 840 ans 14C BP. À l’échelle régionale, l’âge de l’invasion marine des basses terres du Saint-Laurent est estimé à 11 100 ± 100 ans 14C BP (13,15-13 ka BP). Cela corrobore la chronologie varvaire de la Nouvelle-Angleterre (Ridge et al., 1999). La déglaciation de toute la vallée du Saint-Laurent s’est effectuée en moins de 1000 ans 14C. La chronologie de la déglaciation du Québec méridional est rajeunie et raccourcie, ce qui entraîne une révision majeure des événements paléohydrologiques associés.
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 | 0.001 | 0.001 |
| 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 | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".