Did subducted graphite fertilize the Franciscan mantle wedge with radiogenic Os?
Bibliographic record
Abstract
Abstract A new chronology for graphite formation related to subduction-zone metamorphism in Laytonville Quarry (California, USA) of the Franciscan Complex using the Re-Os decay system yields a precise graphite-pyrite Re-Os age of 161.39 ± 2.08 Ma (MSWD = 0.15; n = 5). Combined with Raman thermometry estimates (461–506 °C), this age links graphitization to the early stages of Franciscan subduction, synchronous with deep (blueschist-eclogite) rather than shallow subduction processes. Initial 187Os/188Os (0.195) of Laytonville graphite suggests that radiogenic 187Os/188Os signatures (0.130–0.158) preserved in some Franciscan forearc mantle peridotites (ca. 160–150 Ma) were plausibly sourced from graphitic carbon in the subducted slab, with graphitization being the primary mechanism for Os release. This conclusion implies that graphitic carbon is an important mineralogical host for Os recycling in subduction settings.
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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) | 0.018 | 0.003 |
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".