PLAGIOCLASE-QUARTZ ROCKS OF METASOMATIC ORIGIN AT THE EXPENSE OF GRANITIC ROCKS OF THE KOMAKI DISTRICT, SOUTHWESTERN JAPAN
Bibliographic record
Abstract
In the Komaki district of southwestern Japan, small bodies composed mostly of intermediate plagioclase and quartz occur in a Late Cretaceous granitic batholith. The properties of the plagioclase–quartz rock indicate that the rocks were formed by calcium metasomatism. They are found in a lenticular body 50 m thick and a dome-shaped body 80 m in diameter. The plagioclase–quartz rock formed along fractures and shear zones by hydrothermal replacement of the host granitic rocks. The upper parts of the plagioclase–quartz rock bodies were strongly kaolinized. Greisenized portions are distributed sporadically in surrounding granitic host-rocks. On a 87Sr/86Sr versus 87Rb/86Sr diagram, the regression line formed by the plagioclase–quartz rock and a small stock of leucogranite 1.5 km southwest of the plagioclase–quartz occurrences can be regarded as an isochron, whereas other granitic rocks yield an errorchron. The Rb–Sr isochron age agrees well with the oldest K–Ar age of muscovite from a Mo deposit within the leucogranite. The plagioclase–quartz rock shows significantly lower δ18O compositions relative to the leucogranite and the host granitic batholith, suggesting the contribution of meteoric water. The O and H isotope compositions of clay minerals from the plagioclase–quartz rock suggest that the kaolinization was caused by low-temperature (<150°C) hydrothermal alteration. The geological and geochemical features suggest that the Ca metasomatism was caused by hydrothermal fluids that also produced Mo mineralization. Subsequent to the Ca metasomatism, kaolinization of the plagioclase–quartz rock took place by low-temperature hydrothermal alteration in combination with supergene processes.
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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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| 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".