Age, chemo- and biostratigraphy of Haiti spherule-rich deposits: a multi-event KT scenario
Bibliographic record
Abstract
Examination of two new expanded KT transitions and reexamination of road outcrops near Beloc, Haiti, reveals that deposition of the glass spherule-rich deposit (SRD) occurred within the early Danian Parvularugoglobigerina eugubina (Pla(1)) Zone, followed by an Ir anomaly, and 50 cm above it, a second Pd-dominated platinum group element (PGE) anomaly. The KT boundary is at an erosional unconformity between the base of the SRD and underlying Maastrichtian limestone, where an interval representing about 100250 thousand years appears to be missing (juxtaposition of planktic foraminiferal zones (Pla(1)) and Plummerita hantkeninoides (CF1)). It is possible that the spherule layers are reworked from original deposits at or below the KT boundary. The Ir anomaly is of roughly chondritic-type and compatible with an impact event, whereas the Pd-dominated PGE anomaly is a more basalt-type and compatible with a magmatic origin. This suggests a multi-event scenario consistent with one impact followed by a major volcanic event in the Caribbean or elsewhere.
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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 | 0.001 | 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".