Stratigraphy, sedimentology, tectonics, and resource potential of the Lower Carboniferous Mabou Group, Nova Scotia
Notice bibliographique
Résumé
The upper Lower Carboniferous Mabou Group of Nova Scotia was deposited as the final sedimentary fill into the nearly replete subbasins of a large, intracontinental rift system during the waning stages of tectonic subsidence. Deposition occurred immediately after the short-lived marine carbonate and evaporite realm of the underlying Windsor Group receded. These subbasins lay at a paleolatitude of about 15° in a warm, semiarid, seasonally wet climate. Sedimentation occurred in distensive, fault-bounded subbasins characterized by large total depositional area, and near-vertical stacking of laterally intertonguing formations of moderate thickness. Deposition was influenced primarily by gentle subsidence, and fault-bounded margins were generally located outside the study area. Most detritus was derived from previous sedimentary cover (Horton and Windsor groups). Extraformational pebbles are present in only a few outcrops located close to interpreted subbasin margins. The Mabou Group consists of two lithostratigraphic formations: the lower Hastings Formation, and the upper Pomquet Formation. However, Mabou deposition comprises a single, but internally complex, overall third-order coarsening-upward succession about 500 m thick. This succession begins with shallow-lacustrine muddy deposits (Hastings Formation), which intertongue upward with red, subaerial playa-mudflat-floodplain deposits (Pomquet Formation), which gradually become dominant. The Hastings Formation (of late Viséan - early Namurian age) comprises thin-bedded grey mudstone with interbedded sandstone and limestone of shallow-lacustrine origin. These lithologies are arranged into fourth- and fifth-order, asymmetrical, transgressive-regressive shallowing-upward sequences, deposited in broad, shallow lakes (150 to 200 km long by 100+ km wide in size). Four facies assemblages, which reflect a distal-proximal continuum, are identified in this lacustrine system: dark grey mudstone and sandstone and minor limestone (open lacustrine), grey, very fine- to fine-grained sandstone (lacustrine nearshore and shoreline), minor, red, pedogenic siltstone (subaerial coastal floodplain), and minor, thick, scour-based, very fine- to medium-grained sandstone (high-sinuosity fluvial channel). The intertonguing and overlying Pomquet Formation (of early Namurian age) comprises thin-bedded red siltstone and fine- to medium-grained sandstone, with abundant evidence of vertisol and calcisol pedogenesis. The strata are of subaerial playa-mudflat-floodplain-floodout origin and were deposited as the final fill of the rift subbasins. Four facies assemblages, which reflect a distal-proximal continuum, are identified in this floodplain system: minor thin grey mudstone (very shallow lacustrine); red, massive, pedogenic siltstone (subaerial playa-floodplain-floodout); thick, red, very fine- to medium-grained sandstone (high-sinuosity fluvial channel); and minor, thin, quartz-pebble conglomerate to pebbly sandstone (alluvial fan-braidplain). In comparison to similar deposits of the earlier Horton Group, the Mabou was deposited in less well-defined subbasins that were less dominated by fault-bound subsidence, where carbonate deposition and frequent exposure were more important in the very shallow-lacustrine phase, and fine-grained deposition and pedogenesis were more important in the subaerial phase. Although little direct evidence was found in this study for economic potential, there are some clues suggesting potential for hydrocarbon and redbed copper deposits in the Mabou Group, warranting further investigation.
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 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,001 | 0,001 |
| Communication savante | 0,001 | 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) | 0,002 | 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 ».