Mineralogical, geochronological, and geochemical characterization of Early Devonian aquamarine-bearing dykes of the Zealand Station beryl and molybdenite deposit, west central New Brunswick
Bibliographic record
Abstract
The Zealand Station beryl (aquamarine) and molybdenite deposit is located 25 km northwest of Fredericton, New Brunswick, along the northeastern cusp of the Hawkshaw Granite, previously dated at 411 ± 1 Ma (U–Pb titanite), of the multiphase Devonian Pokiok Batholith. A late-stage, southeast-trending, pegmatite–aplite dyke has abundant aquamarine associated with pegmatitic sections. An exposure of a pegmatitic dyke is predominantly quartz and K-feldspar that exhibits a border, intermediate, and core zone. The main pegmatite–aplite dyke has been dated at 400.5 ± 1.2 Ma using U–Pb thermal ionization mass spectrometry on magmatic zircon. This is consistent with the 404 ± 8 Ma age using the chemical U–Th – total Pb isochron method from the pegmatitic beryl-rich section. These ages link these pegmatitic to aplitic dykes to the Allandale Granite, which is the youngest (402 ± 1 Ma by U–Pb on monazite) and most evolved phase of the Pokiok Batholith. The granitic aplite and pegmatite dyke samples are predominantly magnesian with one pegmatite sample being ferroan (FeOt/(FeOt +MgO) = 0.64–0.94); the samples are slightly potassic and calc-alkaline with strong peraluminosity (A/CNK = 1.23–4.76). The various phases of dykes were derived from magma with crustal A-type source characteristics similar to the Allandale Granite. The Sm–Nd isotope values for the aplite dyke (εNd(400) = –2.15) and the Allandale Granite (εNd(400) = –1.6) reflect some assimilation of metasediments relative to other phases of the Pokiok Batholith. The pegmatite and aplite dykes are high-level, rare-earth element pegmatite phases (Nb–Y–F-type) with some Li–Cs–Ta-type characteristics.
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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 | 0.002 | 0.002 |
| 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".