Bibliographic record
Abstract
The Fox Harbour bimodal volcanic package, newly discovered in 2010 during exploration by Search Minerals Inc. for rare earth elements (REE) is located in southeastern Labrador (northern Grenville Province). This package of rocks consists of three separate belts, known as the Road Belt, MT Belt, and South Belt. They are highly deformed, with an age of formation of 1.3 Ga, determined via U-Pb analysis of zircon from rhyolitic units. A metamorphic age of 1.05 Ga has also been determined for this package of rocks, which is taken to represent time that the Grenville Orogeny affected this area, exposing it to amphibolite facies metamorphism. The Grenville Orogeny is responsible for much of the observed deformation. The MT Belt has undergone the most exploration, due to the fact that the Foxtrot Deposit is located in this belt. This means that a detailed stratigraphy is available, and a much better correlation between rock types and lithogeochemistry is possible for this belt. Geochemically, many of the rhyolite units are peralkaline, determined geochemically, and by the presence of sodic amphiboles and sodic pyroxenes. The REE-bearing mineral in the volcanic units was determined to be a Y-Nb oxide called fergusonite, determined via electron probe micro-analysis (EPMA). Although not analyzed, allanite is also an important REE-bearing mineral found in all mineralized units. Zircon was also analyzed via EPMA, revealing that a zircon population consisting of large microporous grains was different than the general population observed in Fox Harbour. These microporous grains are believed to be 1.05 Ga based on the limited success in obtaining U-Pb dates from them. In-situ determinations of Hf isotopes on the 1.3 Ga zircon crystals reveal that partial melting of 1.5 to 1.9 Ga felsic crustal sources derived the Fox Harbour volcanic units. In-situ Hf determinations of the 1.05 Ga zircon crystal population suggest that these zircon have the same Hf-crustal evolution array for 1.5 to 1.9 Ga sources. This suggests that the 1.05 Ga metamorphism event was a closed system for Lu-Hf, and that there was no flux of REE into or out of the rocks during metamorphism.
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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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".