The sulfur isotopic composition of Cenozoic pyrite is affected by methane content and depositional environment
Bibliographic record
Abstract
• Outcrop δ 34 S pyr is dependent on water depth and lithology. • Sediment δ 34 S pyr is dependent on methane content, sedimentation rate and lithology. • Modern ‘superheavy’ pyrite forms in sediment with high methane concentrations. • There are no clear trends in average δ 34 S pyr over the past 165 million years. The sulfur isotopic composition of pyrite (δ 34 S pyr ) is often used to reconstruct ancient geobiological processes, but recent studies have shown that δ 34 S pyr is strongly dependent on local sedimentary environmental conditions. Here we present a global compilation of >3700 published pyrite sulfur isotopic compositions from the past 165 million years, from outcrop as well as marine sediment cores. We show that sediment core δ 34 S pyr has a statistically significant relationship with methane content, sedimentation rate, lithology, and proximity from shore, while outcrop δ 34 S pyr has distinct distributions depending on categories of depositional water depth and lithology. There are no obvious trends in the average δ 34 S pyr from the late Mesozoic to the present, although we suggest that this temporal record is affected by the inherent bias of data compilation. Our study further emphasizes the importance of considering sedimentology and stratigraphic context when using the sulfur isotopic composition of pyrite to infer global environmental changes.
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 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 | 0.000 |
| 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) | 0.000 | 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".