A >70‐Myr‐Long Geomagnetic Field Reversal Hyperactivity Across the Ediacaran‐Cambrian Transition
Bibliographic record
Abstract
Abstract The long‐term variation of the geomagnetic field is a key constraint for unraveling the geodynamo processes and the evolution of Earth's deep interior. However, the geomagnetic reversal pattern during the Ediacaran–Cambrian transition remains elusive. Here we present an integrated magneto‐ and cyclo‐stratigraphic study of a ∼1.8‐Myr‐long, late Ediacaran succession in Newfoundland, Canada. We obtained a reversal frequency of 10–12 Myr −1 , documenting a hyperactively reversing geodynamo during the late Ediacaran. Together with the updated reversal records and paleointensity data sets, we propose a >70‐Myr‐long interval of geomagnetic reversal hyperactivity before the Ordovician Reversed Superchron, forming a hyperactivity‐superchron couplet that recurs in the mid‐Paleozoic and Mesozoic. These findings suggest that the onset of the ∼200‐Myr‐long cycle in geomagnetic field behavior has occurred since at least ∼570 Ma, earlier than previously envisaged.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 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".