The application of chemostratigraphic techniques to distinguish compound incised valleys in low-accommodation \nincised-valley systems in a foreland-basin setting: an example from the Lower Cretaceous Mannville Group and Basal Colorado Sandstone (Colorado Group), Western Canadian Sedimentary Basin
Notice bibliographique
Résumé
Changes in the bulk inorganic geochemical composition of both sandstones and silty mudstones taken from conventional cores are used to subdivide the Lower Cretaceous Mannville Group and the overlying Colorado Group into chemostratigraphic packages and geochemical units. The chemostratigraphic packages are broadly equivalent to lithostratigraphic formations whereas the geochemical \nunits are represent finer-scale informal stratigraphic subdivisions that occur within the formations. \nThe chemostratigraphic packages are equivalent to the Lower Mannville Formation, the Upper Mannville Formation, the Basal Colorado Sandstone (an informal unit at the base of the Colorado Group), and the overlying Joli Fou Formation. The changes, which enable each lithostratigraphic unit, or chemostratigraphic package, to be geochemically fingerprinted, are primarily related to changes in mineralogy,which in turn appear to coincide with changes in sediment provenance and basin architecture. These chemostratigraphic packages, which are broadly equivalent to lithostratigraphic formations, can be considered to result from first-order changes in whole-rock geochemistry. \nThe geochemical units are equivalent to incised-valley-fill sequences within the lithostratigraphic units, and here it is shown that the incised-valley-fill sequences of the Upper Mannville and Basal Colorado Sandstone each have a unique geochemical signature. Three incised-valley-fill sequences are present in the latter intervals, the oldest of which lie within the Upper Mannville Formation. Valleys at the base of the Basal Colorado Sandstone incise Upper Mannville deposits and are termed the lower Basal Colorado sandstones. The youngest valleys lie at the top of the Basal Colorado Sandstone and are termed the upper Basal Colorado sandstones. The sedimentary deposits in each of these incised valleys can be chemically distinguished from one another, even where a sandstone-on-sandstone contact is present in a single wellbore. The geochemical changes that enable each incised-valley fill to be recognized can be considered as second-order variations and are referred to as geochemical units. Stacked valleys observed in the Lower Mannville Formation have been the subject of previous chemostratigraphic work, and all of these have a unique geochemical signature and are also considered here to be geochemical units. \nThe base of each incised-valley-fill succession, or geochemical unit, is a sequence boundary. By enabling clear identification of the geochemical unit above and below a sequence boundary, the technique of chemostratigraphy has direct application to aiding both lithostratigraphic and sequence stratigraphic correlations in low-accommodation basin settings.
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 | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 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 ».