Depositional Controls on ∆′ <sup>17</sup> O Signatures of Sedimentary Sulfate
Bibliographic record
Abstract
Abstract Triple oxygen isotope compositions of sedimentary sulfate (∆′ 17 O) have been applied as a tracer of past primary productivity, p O 2 and p CO 2 . However, large intraformational variability and debate surrounding how such signatures are produced and preserved has limited the understanding of this record. Here we explore what controls ∆′ 17 O signatures of mid‐Proterozoic (ca. 2.0–1.0 Ga) sulfates. We identify a clear depositional control on the magnitude of preserved sulfate ∆′ 17 O signatures, with Proterozoic terrestrial environments preserving the most negative and variable signatures and marine environments displaying values near modern marine sulfate. Our results strongly suggest that local depositional setting influences the magnitude of preserved ∆′ 17 O signals, and that the processes within local environments drive much of the observed intraformational variability. Finally, this analysis suggests that ∆′ 17 O signatures of carbonate associated sulfate in concert with sedimentological observations may offer a powerful tool to identify basin restriction and non‐marine settings throughout the geologic record.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| 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 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".