Impact of Vegetation On Early Pennsylvanian Fluvial Channels: Insight From the Joggins Formation of Atlantic Canada
Notice bibliographique
Résumé
Abstract: Riparian vegetation profoundly influences modern fluvial channels in a variety of ways, depending on the life-history strategies of different plant types, disturbance frequency, and drainage conditions of available habitats. Direct evidence for these dynamic relationships is usually cryptic in ancient deposits. We report evidence for interactions between rivers and in situ vegetation for selected sites in the lower Pennsylvanian Joggins Formation of Atlantic Canada, encompassing fixed, meandering, and distributary channels originally up to 6 m deep. Channel bodies are associated with a suite of fossilized plant remains, specifically lycopsids that preferred stable wetland settings, disturbance-tolerant calamitaleans, and slow-growing, long-lived cordaitaleans. Vegetation was effective in stabilizing banks and bars and promoting aggradation. Lycopsids and calamitalean groves colonized the channel bed during periods of reduced flow, drawing on the groundwater table, and mounds around upright trunks indicate that they formed bar nuclei after flow resumed. Bank-attached bars with lateral-accretion sets contain upright trees, which may have stabilized inclined sediment surfaces, and trees present between small distributary channels may have formed vegetated islands. Erect lycopsids rooted below the channel base project up into the channel fill, where they formed obstacles and nucleated sediment mounds in active channels. On channel cutbanks, upright lycopsids are tilted towards the channel, and early formed rhizoconcretions are associated with deep cordaitalean root systems in the tops of channel fills. These features imply that vegetation contributed to stabilization of sediment surfaces. The predominance of in situ over transported plant remains suggests that these low-flow-strength rivers had limited ability to erode and entrain large woody debris, especially for small channels with strengthened banks. We infer that patterns of interaction between vegetation and rivers with a range of fluvial style broadly resembled those of today. By the early Pennsylvanian, rivers had moved from a geomorphic and biogeomorphic mode of operation into a fully ecological mode with prominent feedback loops between vegetation and fluvial processes. Vegetation is commonly poorly preserved in fluvial systems but should be incorporated into facies models for Pennsylvanian and younger strata, possibly also for some Devonian and Mississippian formations.
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) | 0,000 | 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 | 0,000 |
| 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 ».