MAGMATIC HYDROTHERMAL FLUIDS AND THE ORIGIN OF OUARTZ _ TOURMALINE ORBICULES IN THE SEAGULL BATHOLITH,
Bibliographic record
Abstract
The mid-Cretaceous Seagull batholith in the Yukon Territory consists of meta- to peraluminous granite in which tourmaline generally occurs as an accessory phase. The roof zone of the granite is, however, characterized by the presence of quartz-tounnaline orbicules that constitute up to l0 to l5q0 of the granite. The orbicules are typically 6 to 8 cm in diameter, and contain up to 40q0 tourmaline, the remainder being chiefly quartz, feldspar, and minor fluorite. Miarolitic cavities lined with quartz, tourmaline, and rare topzv occur in the center of some orbicules. The orbicules crystallized from a mixture of residual borosilicate melt and hydrothermal fluid. Quartz, tourmaline and fluorite contain primary aqueous fluid inclusions. Salinities range from 8 to 42 equiv. wt.9o NaCl + CaCl2. As the orbicules crystallized as closed systems, these inclusions contain unevolved orthomagmatic hydrothermal fluids. Large variations in salinity of fluids associated with epizonal plutons thus do not have to be explained by boiling or mixing with meteoric water. Isochoric projections indicate that crystallization took place between 600 and 3@'C, and possibly as low as 150'C. Solids associated with some of these inclusions demonstrate that the fluids were in equilibrium with muscovite, indicating that they would cause phyllic alteration during migration through previously crystallized granite. Elevated concentrations of tin in the orbicules and the presence of quartz-tourmaline-cassiterite veins in the granite indicate that, on occasion, the fluids migrated away from the magma and were responsible for the tin mineralization associated rr/ith the granite.
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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 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| 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".