Micromagnetics and magnetomineralogy of ultrafine magnetite inclusions in the Modipe Gabbro
Bibliographic record
Abstract
Iron oxide inclusions in pyroxene crystals from the Modipe Gabbro, Botswana, have been studied to determine their recording fidelity. Hysteresis parameters, first‐order reversal curves, isothermal remanent magnetization acquisition curves, and thermomagnetic data all indicate that the iron oxide occurs as stoichiometric magnetite in the form of single‐domain and/or small pseudo single‐domain particles. Using distributions for the grain shape and nearest‐neighbor spacings determined from optical micrographs as input, a first‐order reversal curve (FORC) diagram was simulated using a numerical micromagnetic model. The simulated FORC diagram was found to closely match the measured FORC distributions. Analysis of the interaction fields in the model found that the standard deviation of the interaction field distribution was 2.7 mT compared to a bulk coercivity of ~20 mT, suggesting that the majority of particles are unlikely to be affected by magnetostatic interactions. Thellier analysis of the samples induced with an initial laboratory thermoremanence yielded near‐perfect behavior. It is suggested that the Modipe Gabbro dated at 2784.0 ± 1.5 (2σ) Ma is potentially an ideal recorder of the geomagnetic field.
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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 | 0.000 | 0.000 |
| 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) | 0.000 | 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 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".