Mineralogical and spectroscopic investigation of enstatite chondrites by X-ray diffraction and infrared reflectance spectroscopy
Bibliographic record
Abstract
[1] The mineralogy and infrared reflectance spectra of 13 Enstatite (E) chondrite meteorite finds spanning the full range of textural alteration grades in both EL and EH classes have been investigated. Rietveld refinement of high-resolution powder X-ray diffraction (XRD) data was used to determine quantitative major mineral abundances. Sample-correlated mid-infrared (2.0 to 25.0 μm; 4500 cm -1 to 400 cm -1 ) reflectance infrared spectra were collected for each meteorite. Spectral features due to the fundamental lattice vibrations of the silicates, primarily enstatite, dominate the spectra of these meteorites over most of the spectral range investigated. The spectral features related to primary (i.e., pre-terrestrial) mineralogy include fundamental stretching and bending lattice modes (-8.3-25.0 μm; 1200-400 cm -1 ), overtones and combinations of the fundamental modes (∼4.5-6.1 μm; 2200-1650 cm -1 ), and the principle Christensen feature (-8.3 μm; 1200 cm -1 ). Terrestrial weathering products including Fe-oxyhydroxides, gypsum, and carbonates occur in most of these meteorites and contribute to some spectral features: particularly an asymmetric feature near ∼2.6 to 3.8 μm (3800 to 2600 cm -1 ) attributed to adsorbed, hydrogen-bonded, and/or structural OH and H 2 O, and a feature near -6.2 μm (1625 cm - 1 ) attributed to adsorbed, hydrogen-bonded, and/or structural H 2 O. Modal mineral abundances determined by Rietveld refinement have been used to calculate model grain densities for each meteorite. Bulk magnetic susceptibility measurements combined with modal mineralogy and grain densities reveal a trend toward lower grain density and lower bulk susceptibility with increased terrestrial weathering.
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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 | 0.000 |
| 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 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".