GEOCHEMICAL AND MORPHOLOGICAL FEATURES OF BERYL FROM THE BIKITA GRANITIC PEGMATITE, ZIMBABWE
Bibliographic record
Abstract
Nous avons examine l'evolution geochimique du beryl dans la pegmatite granitique a elements rares de Bikita, au Zimbabwe, au moyen de donnees sur les teneurs en alcalins dans vingt-trois echantillons de ce mineral, preleves sur les huit zones de ce massif geant. A partir des zones externes vers les zones internes de la pegmatite, correspondant aux parties les plus primitives vers les parties plus evoluees, les teneurs en alcalins des cristaux presque homogenes de beryl primaire augmentent de 0.09 a 1.08% Li 2 O, de 0.39 a 1.56% Na 2 O et de 0.10 a 2.23% Cs 2 O (poids). L'incorporation du Li dans les tetraedres hotes du Be est compensee d'abord par le presence du Na dans les canaux de la structure, mais dans les echantillons plus evolues pris des zones internes de la pegmatite, le Cs devient le cation le plus important dans l'equilibre des charges. Un seul echantillon de beryl subsolidus rosâtre, se presentant en plaquettes minces empilees parallele a {0001}, avec un rapport epaisseur:diametre atteignant 1:50, fait preuve de caracteristiques geochimiques en partie paralleles, en partie divergentes, par rapport a celles du beryl primaire. Les plaquettes de beryl tardif possedent un coeur a faible teneur en alcalins, avec surcroissances de beryl riche en alcalins, atteignant 1.15% Li 2 O, 2.01% Na 2 O et 3.48% Cs 2 O. En general, toutefois, les teneurs en alcalins diminuent des plaquettes precoces aux plaquettes tardives de cet amas. La morphologie inhabituelle de cet echantillon en plaquettes empilees ne dependrait pas des teneurs en alcalins, mais plutot d'un autre facteur, qui demeure meconnu.
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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".