Bibliographic record
Abstract
Overview In this chapter, we discuss some of the other well-documented K–T boundary localities in North America outside of the Williston Basin. These localities are situated in other sedimentary basins in a south-to-north corridor from New Mexico to Alaska, including parts of western Canada (Figure 7.1). Collectively these localities contribute to a large database of information about plants and the K–T boundary, although it will became clear to the reader that the quality of the records varies from one to the next. The south-to-north geographic distribution of these basins constitutes a proximal-to-distal array with respect to the postulated K–T impact crater on the Yucatan Peninsula of Mexico. This fact appears to have particular relevance with respect to preservation of a boundary claystone layer and other indicators of the K–T boundary discussed in Section 2.3, such as shocked minerals. Raton Basin, Colorado and New Mexico The first iridium-bearing terrestrial K–T boundary sections were discovered in the Raton Basin of southeastern Colorado and northeastern New Mexico (Figure 7.2). The K–T boundary is preserved in the Raton Formation, an entirely nonmarine unit of Maastrichtian and early Paleocene age (Figure 7.3). The Raton Formation is composed of sandstone, siltstone, mudstone, coal, and minor conglomerate. Thin to thick coal beds are common in the lower and upper parts of the formation, but are scarce to absent in the middle “barren series,” which is composed largely of sandstone.
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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 | 0.006 | 0.014 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.028 | 0.006 |
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".