The nature and origin of REE mineralization in the Misery syenitic intrusion, Northern Québec, Canada
Notice bibliographique
Résumé
As a result of the recent increase in demand for the rare earth elements, the newly discovered Misery syenitic intrusion is attracting considerable exploration interest. This REE-Zr-Nb prospect is located 200km east of Schefferville and 70km south of Strange Lake in Québec, Canada. It is a 6km wide, ring-shaped intrusion conspicuous on aeromagnetic maps that was emplaced within the Mistastin Batholith, a large Elsonian age granitoid body, which intrudes Paleoproterozoic rocks of the Churchill Province. The Misery intrusion displays a gradational contact with its host, the Misastin rapakivi granite. Both have an A-type affinity and similar trace element composition. The Misery syenites are therefore interpreted to be a late differentiate product of the Mistastin batholith. The dominant exposed lithology (much of the intrusion is covered by a lake) is a felsic syenite, which is mainly composed of perthitic K-feldspar and 1 to 10 volume% of interstitial ferromagnesian minerals, namely fayalite, hedenbergite, ferropargasite and annite (iron rich biotite); the accessory minerals are quartz, iron oxides (magnetite, Ti-rich magnetite and ilmenite), zircon, fluorite, apatite and britholite. A melanocratic unit, ferrosyenite, which contains up to 50 volume % ferromagnesian minerals, including cumulate fayalite and hedenbergite, occurs as amoeboid-like inclusions in the felsic syenite. The ferrosyenite is interpreted to have formed by fractional crystallization of ferromagnesian minerals leaving behind a residual magma which produced the felsic syenites. With continued fractional crystallization, the felsic syenites became more enriched in alkali and silica, and only became saturated with ferromagnesian at a very late stage explaining the interstital crystallization of the latter in the perthite-dominated felsic syenites. The bulk of the REE mineralization (dominantly LREE) is concentrated in pods and layers as hydroxyapatite. Much of this mineralization accumulated through gravity settling in felsic syenite and ferrosyenite, commonly in association with magnetite. The hydroxyapatite crystals were partly or completely replaced by britholite-(Ce), which further concentrated the REE, and crystallized from post-magmatic hydrothermal fluids, which reacted with the magmatic hydroxyapatite. Locally, the felsic syenites underwent sodic metasomatism and where this occurred, the REE were remobilised again to form fluorocarbonate minerals (bastäsite-(Ce), parisite-(Ce) and synchysite-(Ce)). The Misery intrusion and the Mistastin granitoids surrounding it were cut by numerous narrow dykes composed mainly of quartz, fayalite, zircon and fergusonite-(Y). These dykes are interpreted to be products of a FeO-SiO2-rich melt that separated from the main syenite melt and into which Zr and Nb were preferentially fractionated. These dykes represent a new and interesting target for HREE exploration.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,002 | 0,002 |
| Études des sciences et des technologies | 0,002 | 0,001 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,003 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».