Data and Supplementary Information: Nelson et al., 2025, American Journal of Science
Bibliographic record
Abstract
Data and Supplementary Information for "A basin in transition: ecological, environmental, and tectonic shifts across the Ediacaran–Cambrian boundary in the Nama Group, Kalahari Craton." Lyle L. Nelson1,2*, Emily F. Smith3, Simon. A. F. Darroch4, Iona Baillie3, Jahandar Ramezani1, John E. Almond5, Roger Swart6, Dana E. Polomski1, Katherine A. Turk7 1Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA 2Department of Earth Science, Carleton University, Ottawa, Ontario K1S 5B6, Canada 3Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA 4Senckenberg Museum of Natural History, Frankfurt 60325, Germany 5Natura Viva cc, PO Box 12410 Mill Street, Cape Town 8010, Republic of South Africa 6BlackGold Geosciences cc, P.O. Box 24287, Windhoek, Namibia 7Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA *Corresponding author: llnelson@mit.edu Table SI1. U-Pb isotopic data for zircon analyses from upper Swartkloofberg Formation ash bed E2107, Neint Nababeep Plateau, South Africa. Table SI2. Carbon and oxygen isotope data of limestones from the upper Swartkloofberg Formation, Neint Nababeep Plateau, South Africa. Figure SI1. Photographs of ash beds and dated zircons. A) Outcrop photograph of silicified ash bed in limestone of the Spitskop Member, upper Schwarzrand Subgroup, Neint Nababeep Plateau; example of the distinctive lithology of ash beds in this succession; 33 cm hammer for scale. B) Outcrop photograph of silicified ash bed (sample E2107) within stromatolite reef complex of upper Swartkloofberg Formation, Neint Nababeep Plateau; 33 cm hammer for scale. C-D) Photomicrographs of sharp euhedral zircon grains separated from sample E2107. The age of this volcanic ash bed was calculated at 537.64 ± 0.25 Ma based on the weighted mean of a statistically coherent cluster of 206Pb/238U dates from four of these zircon grains, after excluding a single older analysis interpreted to represent a detrital or xenocrystic zircon (fig. 12).
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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 | 0.024 | 0.004 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.000 |
| Bibliometrics | 0.004 | 0.006 |
| Science and technology studies | 0.001 | 0.007 |
| Scholarly communication | 0.003 | 0.028 |
| Open science | 0.041 | 0.072 |
| Research integrity | 0.000 | 0.003 |
| Insufficient payload (model declined to judge) | 0.003 | 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; both teacher heads agree on what is shown here.
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".