Till composition across the Keewatin Ice Divide in the Tehery-Wager GEM-2 Rae project area, Nunavut
Notice bibliographique
Résumé
This report releases the field database and analytical results from a targeted surficial geology and till sampling survey completed in 2015 and 2016 south of Wager Bay in mainland Nunavut as part of Natural Resources Canada's Tehery-Wager GEM-2 Rae project. The report also provides a summary of the regional bedrock and surficial geology, an improved glacial history framework, and a detailed description of the field and analytical methods. A preliminary interpretation regarding till provenance and mineral potential integrates all previous government till surveys in the region. The uplands south of Wager Bay coincide with a relatively stable position of the Keewatin Ice Divide (KID) and are dominated by a mixture of bouldery till blankets and veneers, weathered bedrock and diamictons, and boulder fields. The deeply weathered terrain under parts of the KID indicates the preservation of a pre-LGM landscape under cold-based ice conditions. South of the divide, the predominant regional trend of streamlined bedrock and till landforms varies from SSE to SE, parallel to main striation directions. A complex system of subglacial meltwater corridors and proglacial meltwater channels overprints the streamlined till that extends away from the KID. A later S to SSE deglacial event locally cross-cuts the streamlined terrain and corridors suggesting a northward ice margin retreat. The post-glacial marine limit increases from ~118 m asl southwest of Wager Bay near Paliak Islands to 140 m along Roes Welcome Sound and stays relatively constant at 140-150 m westward towards Tehery Lake. A total of 73 regional till samples collected in 2015 and 2016 to evaluate mineral potential and characterize regional transport across the KID were analyzed for matrix texture, colour, carbon content, indicator minerals, pebble count, as well as geochemistry of the <0.063 mm fraction. All field observations (202 stations) and till composition datasets were compiled in separate spreadsheet files. Surface till consists of a silty sandy, granitic-rich diamicton and is commonly bouldery on the surface. Till has a significant local component and its composition reflects the underlying bedrock glacially transported away from the KID. The eastern sector is dominated by more immature tills, higher in sand content but with relatively high clay contents derived from highly erodible, poorly resistant weathered lithologies preserved under the KID. The distribution of heavy minerals picked as potential kimberlite indicator minerals (KIMs) in surface tills suggests glacial dispersal from diverse ultramafic and mafic bedrock sources: the Nanuq kimberlite field, mafic to ultramafic bodies within the Lorillard domain, undeformed ultrapotassic mafic intrusions, and possibly unknown kimberlite. In particular, the distribution of Ca-forsterite, eclogitic garnet and Cr-pyrope forms a 60-km long SSE-trending regional dispersal train from the Nanuq kimberlite bodies, parallel to the dominant ice flow direction. On the other hand, the presence of a significant number of Cr-pyrope, eclogitic garnet, Ca-forsterite, low Cr-diopside and bronzite grains in till south of Meen Lake suggests a clear potential for a local kimberlitic source up-ice (northwest) of the sample. The potential for Ni-Cu, platinum group elements (PGEs) and chromite mineralization in the region mainly lies in Archean komatiite/pyroxenite/peridotite ultramafic bodies of the Lorillard domain as shown by a large SE trending fan-shaped dispersal train of forsterite and a shorter SE dispersal train of chromite grains. Elevated to moderate concentrations of base and precious metals, metamorphosed or magmatic massive sulphide indicator minerals (MMSIMs) and gold grains in gossan-rich till and down-ice of supracrustal rocks within the northern part of the Lorillard domain indicates potential for base- and precious metal mineralization in this area. Smaller gossanous horizons were mapped in several other supracrustal panels (e.g. Pennington belt) north of the Chesterfield shear zone and till composition in this area indicates potential for metamorphosed volcanogenic massive sulphide (VMS) deposits.
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,002 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,001 |
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 tête enseignante, 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 ».