Conodonts recovered from the carbonate xenoliths in the kimberlites confirm the Paleozoic cover on the Hall Peninsula, Nunavut
Bibliographic record
Abstract
Hall Peninsula, located on southeastern Baffin Island, Nunavut, hosts the newly discovered Chidliak kimberlite province. Presently, this area lacks Phanerozoic sedimentary cover, except for the unconsolidated glacial deposits; however, Late Ordovician and Early Silurian microfossil conodonts have been recovered from carbonate xenoliths preserved in the Late Jurassic – Early Cretaceous kimberlites. Over 1300 conodont specimens were recovered, among which 32 species representing 23 genera are recognized, with four elements indeterminate. The well-preserved conodont faunas provide reliable evidence on the Hall Peninsula for (i) reconstructing the Lower Paleozoic stratigraphic units, including the Upper Ordovician Frobisher Bay, Amadjuak, Akpatok, and Foster Bay formations, and the Lower Silurian Severn River Formation, (ii) estimating a total of 270–305 m in thickness of Lower Paleozoic sedimentary cover prior to the emplacement of the kimberlites, (iii) tracing the erosion history after the emplacement of the kimberlites, and (iv) calculating a minimum erosion rate of 2 m/Ma. The conodonts have a wide range of conodont Color Alteration Index (CAI) values between 1.5 and 8, which is the largest range recorded in any known suite of xenoliths entrained in kimberlites.
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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 | 0.001 |
| 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".