Stratigraphic architecture and facies analysis of the Lower Cretaceous Dina Member of the Mannville Group in Northwest Saskatchewan.
Notice bibliographique
Résumé
The Dina Member in northwest Saskatchewan was deposited unconformably on top of the underlying Devonian Elk Point Group with the thickest Dina sandstones residing within paleo-topographic lows on the unconformity surface. The Dina Member was extensively eroded by Pleistocene glacial processes and is unconformably overlain by Pleistocene glacial tills. Analysis of 83 stratigraphic test hole drill cores and 255 geophysical well log suites has revealed 8 recurring facies and 5 facies associations. The facies are comprised of siliciclastic sediments, including sandstones, siltstones, mudstones and in rare instances, coal. These facies are predominantly non-marine in origin, including fluvial sediments and associated over-bank deposits. Many fluvial facies exhibit a significant tidal and/or seasonal brackish water influence. Tidal indicators are manifested as rhythmic grain size striping, reactivation surfaces and co- and back-flow structures. Brackish conditions are indicated by impoverished, mono-specific assemblages of diminutive trace fossils in mud beds and discrete sand layers, along with marine palynmorphs and microfossils. Deposition of the Dina Member is interpreted to have occurred within an incised valley system formed as a result of a relative base-level drop, which initiated trenching and deepening of pre-existing valleys. Braided channel deposits proceeded to fill the lowest portions of the valley during the lowstand and part of the subsequent transgression. As the valley was gradually filled and the lateral accommodation space increased, fluvial style changed from braided to meandering, with deposition of laterally accreted point-bar deposits. These manifest as inclined stratification (IS) and inclined heterolithic stratification (IHS) overlying basal trough cross-bed sets. Mud filled, oxbow lake deposits were also observed in close association with the point-bar deposits. Bitumen distribution throughout the study area is not uniform and has several controls. Bitumen saturation is highest where braided fluvial and IS deposits are found, especially when stacked. Conversely, IHS deposits and mud filled oxbow lake deposits restrict oil flow and in cases act as flow barriers to oil migration. Bitumen is trapped laterally by the incised valley walls created by the sub-Cretaceous unconformity, where bitumen saturated sand pinches out against the impermeable carbonates. The Dina sandstones, in turn, were sealed above by shales of the Clearwater Formation/ Cummings Member of the Mannville Group.
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 | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| 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 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 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 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 ».