GRANITIC PEGMATITES OF THE O'GRADY BATHOLITH, N.W.T., CANADA: A CASE STUDY OF THE EVOLUTION OF THE ELBAITE SUBTYPE OF RARE-ELEMENT GRANITIC PEGMATITE
Bibliographic record
Abstract
The first confirmed Canadian occurrence of the elbaite subtype of rare-element granitic pegmatite has been encountered within the O’Grady batholith, approximately 100 km NNW of Tungsten, N.W.T. The batholith, part of the Selwyn plutonic suite, is a mesozonal, hornblende-bearing, metaluminous composite intrusion with lesser amounts of pegmatitic granite and felsitic satellite dykes. On the whole, pegmatite bodies show a mildly NYF-type geochemical and mineralogical signature (allanite- and magnetite-bearing), but in the region of the pegmatitic granite, they grade toward a distinct LCT-type signature (elbaite-bearing). The melts parental to the pegmatite bodies were more voluminous, more alkaline, less aluminous and less reduced than is the norm for melts parental to LCT-type pegmatite. Differentiation of these melts sequentially produced hornblende granite, pegmatitic leucogranite and pegmatite, as shown by major-, minor- and trace-element geochemistry of K-feldspar, plagioclase, micas, tourmaline, amphibole and a variety of accessory phases. Lithium-mineralized pegmatite is recognized by the presence of multicolored elbaite, by lepidolite, and in the diversity of characteristic accessory phases such as danburite, hambergite, stibiocolumbite, pollucite, a nanpingite-like mineral, and bismutite. The various stages of the evolution of the batholith can be well documented in similar variations in mineral chemistry, and result in one of the few well-characterized case studies of the elbaite subtype.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 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".