A Silicocarbonatitic Melt and Spinel-Bearing Dunite of Crustal Origin at the Parker Phlogopite Mine, Notre-Dame-du-Laus, Quebec, Canada
Bibliographic record
Abstract
The Parker phlogopite mine, located near Notre-Dame-du-Laus, Quebec, 74 km north of Ottawa, is well known among mineral collectors for its centimetric euhedral crystals of black spinel. Among the dozens of phlogopite mines active in the early 1900s in the Mont-Laurier–Bancroft corridor in the Central Metasedimentary Belt of the Grenville Province, the Parker mine is exceptional because of the association of forsterite + spinel with phlogopite. Euhedral crystals of these minerals are found “frozen” in a carbonate matrix. The carbonate dike and segregations are associated with spinel-rich dunite that contains accessory diopside, phlogopite, and pargasite, as well as ilmenite and apatite. The interstitial melt crystallized to calcite + dolomite. Hematite appeared as flakes in the melt owing to net loss of hydrogen, and the spinel underwent oxidation-induced exsolution. Our spinel crystal entrapped a domain of carbonate during growth. It also entrapped globules of boundary-layer melt that crystallized to a carbonate + sulfate + phosphate + silicate + oxide assemblage. Such globules, where present in the cumulate, are more pristine than in the coarse crystal of spinel, i.e., less affected by a hydrothermal overprint. We contend that the carbonate melt ultimately formed by the hydrous melting of marble, as supported by oxygen-isotope data on all major minerals. Melting occurred 1140 million years ago, at a time of tectonic relaxation following the Shawinigan compressive stresses.
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 | 0.001 | 0.001 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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".