MARIANOITE, A NEW MEMBER OF THE CUSPIDINE GROUP FROM THE PRAIRIE LAKE SILICOCARBONATITE, ONTARIO
Bibliographic record
Abstract
Marianoite, a new member of the cuspidine group of minerals, occurs in phlogopite–calcite silicocarbonatite in the western part of the Mesoproterozoic Prairie Lake intrusive complex, in northwestern Ontario, Canada. The mineral forms flattened prismatic crystals with resorbed faces, up to 0.3 mm in length, and is associated with uranoan pyrochlore, titanite and natrolite–muscovite pseudomorphs after xenocrystic nepheline. The crystals are translucent, very pale yellow macroscopically and colorless in plane-polarized light. The mineral is biaxial negative (α 1.700, β 1.715, γ 1.725, 2 V meas 80°, 2 V calc 78°) and shows a weak optic-axis dispersion ( r v ). Marianoite is relatively homogeneous in composition; its average empirical formula is Na 1.93 (Ca 4.00 Mn 0.04 ) ∑4.04 (Nb 0.97 Zr 0.90 Ti 0.09 Fe 0.08 Mg 0.03 Hf 0.01 ) ∑2.08 (Si 3.97 O 14 )O 2.93 F 1.07 . By analogy with wohlerite, the simplified formula of marianoite should be written Na 2 Ca 4 (Nb,Zr) 2 (Si 2 O 7 ) 2 (O,F) 4 . The structure of the new mineral species, refined by single-crystal methods to an R 1 of 4.65% (for | F o | > 4σ F ), is monoclinic, space group P 2 1 ; the unit-cell parameters are: a 10.8459(15) A, b 10.2260(14) A, c 7.2727(10) A, β 109.332(3)°, V 761.1(3) A 3 ( D calc 3.45 g/cm 3 ). The mineral is isostructural with wohlerite [Na 2 Ca 4 (Zr,Nb) 2 (Si 2 O 7 ) 2 (O,F) 4 ], but shows the preponderance of Nb in the smallest octahedrally coordinated cation sites in its crystal structure. The occupancy of these sites cannot be determined accurately because of the similar X-ray scattering characteristics and ionic radii of Nb 5+ and Zr 4+ . The mineral is named in honor of Anthony Nicola Mariano (b. 1930), in recognition of his contributions to the study of alkaline rocks and carbonatites.
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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 | 0.001 | 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".