Messengers from the Asteroid Belt: A Study of Diogenites Northwest Africa 10268 and 7464
Bibliographic record
Abstract
The study of meteorites is crucial to understanding the geological evolution of our early solar system. In this study, we observe optical and chemical properties of two diogenite meteorites (Northwest Africa 7464 and 10268) that originated from the second-largest asteroid, 4 Vesta. By studying the mechanical deformation and transformation features of feldspar, olivine and pyroxene grains within the samples, we are able to constrain the shock stage of each meteorite. Northwest Africa 7464 and 10268 were both observed using a scanning electron microscope, an energy dispersive x-ray spectrometer, an electron microprobe, a petrographic microscope and a Raman spectrometer. Northwest Africa 7464 exhibits weak mosaicism and planar fractures in pyroxene, as well as, undulatory extinction and planar fractures in olivine. These features suggest a moderately-shocked S4 meteorite consistent with a shock pressure of between 4-20 GPa. Northwest Africa 10268 contains opaque shock veins associated with the diaplectic plagioclase glass, maskelynite. This host rock exhibits strong mosaicism and undulatory extinction in pyroxene, as well as, twinning in crystalline feldspar. These features are consistent with a strongly shocked S5 meteorite, experiencing a shock pressure of between 22-25 GPa. These results give insight on shock pressure and temperature conditions that occur on 4 Vesta. Department: Physical Sciences Faculty Mentor: Dr. Erin Walton
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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 | 0.001 | 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) | 0.001 | 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".