Petrography, geochemistry, age, and stratigraphic significance of the Mississippian Boyd Creek tuff, southern New Brunswick, Canada
Bibliographic record
Abstract
The Boyd Creek tuff consists of two pyroclastic flow deposits and more widespread air-fall tuff within a Mississippian red bed sequence located in outcrop and boreholes around Weldon and Pre d’en Haut, Albert and Westmorland counties, New Brunswick. Long recognized as an important stratigraphic marker, it has been placed in either the Tournaisian Weldon Formation or Visean Hillsborough Formation by previous workers, with a position in the upper Tournaisian Weldon Formation being the most recent interpretation. A Visean laser ablation-inductively coupled plasma-mass spectrometry U–Pb zircon age of 336.9 ± 2.0 Ma is consistent with the interpretation that the tuff is part of the Windsor Group and within a fine-grained red and grey sequence of the Hillsborough Formation. Although the tuff is altered and contains abundant xenoliths and xenocrysts, petrography and chemistry are consistent with rhyolite or dacite composition. Its composition and age suggest that the Boyd Creek tuff is one of several volcanic units interpreted to be in the Windsor Group or its temporal equivalents, including rhyolite-trachyte lavas of Cumberland Hill (Cumberland Hill Formation, Mabou Group), tuff in carbonate-evaporite sequence at the Picadilly Mine (Penobsquis), and the red bed Shin Formation (Mabou Group) at Hurley Creek near Minto. Locating and dating other ‘ash beds’ in the Windsor Group offers a way to resolve long-standing issues of correlation in the Visean of New Brunswick and Nova Scotia.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 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) | 0.001 | 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 teacher head, 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".