10Be exposure dates from pre-Illinoian glacial erratics deposited near the southern terminus of the Laurentide Ice Sheet
Bibliographic record
Abstract
The remnants of multiple ice sheet expansions beyond the southern limits of the Wisconsinan glaciation (ca. 75−12 ka, Marine Isotope Stage [MIS]-4 and MIS-2) and the Illinoian glaciation (ca. 191−125 ka, MIS-6) are present in north-central USA. Sioux Quartzite-rich glacial erratics in northeast Kansas, USA, have marked the southernmost extent of the Laurentide Ice Sheet during the Quaternary (38°−39°N). However, the timing of pre-Illinoian ice advances remains uncertain. To date deglaciation, we measured cosmogenic 10Be in five quartzite boulders on hilltops near Wamego, Kansas (39.14°N, 96.26°W). Apparent exposure ages (248.3−74.7 ka) are younger than previous pre-Illinoian retreat evidence. These dates, coupled with exhumation histories, suggest complex geomorphological processes revealing the boulders are from a deposit, supporting their origin as lag deposits from a once thick, weathered till deposited at least several hundred thousand years ago.
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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 | 0.000 |
| 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) | 0.002 | 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".