Genesis of Palimpsest Cool-Water Carbonate Sediment on the Continental Margin of Southern Australia
Notice bibliographique
Résumé
Abstract The continental margin of southern Australia is a site of extensive Quaternary cool-water carbonate sedimentation. Seafloor sediments are a mixture of Holocene biofragments and late Pleistocene relict and stranded particles. Relict sediments, produced during Marine Isotope Stages 3 and 4, are generally preserved as iron-stained intraclasts. Such grains in the Great Australian Bight are photozoan in character. They include symbiont-bearing benthic foraminifers and coralline algal particles, and indicate that the wide shelves were bathed in shallow, relatively warm, oligotrophic waters and floored by marine grasses, similar to many modern shallow inboard embayments in the region today. In contrast, east of the Great Australian Bight relict sediments are more heterozoan in character, with coralline algal and molluscan facies on the inner shelf and bryozoan sediments on the outer shelf. Stranded sediments, marooned during the sea-level rise associated with Marine Isotope Stage 2, are gray to buff in color and composed of both biofragments and intraclasts. These particles are mainly heterozoan in character throughout the region, with subtropical photozoan marine grassbank facies localized to portions of the inner Great Australian Bight. Stranded sediments are interpreted to have accumulated in an areally restricted photic zone and upon an overall narrow shelf covered in cool, nutrient-rich waters. Swell-driven seafloor sediment disturbance to depths of 100 m along the southern Australian margin in conjunction with reduced rates of sedimentation that characterize the cool-water carbonate realm, have resulted in mixing of sediment currently being produced with exhumed relict and stranded sediments generated during previous sea-level stands. The composition of these deposits and the nature of their pre-burial alteration are a function of sea-level history. Late Pleistocene relict sediments originally accumulated in low-energy, inboard environments but were modified in the surf zone during subsequent sea-level fluctuations. This resulted in the formation of intraclasts: abraded, infilled, and cemented biofragments of local origin. The widespread distribution of intraclasts and of composite grain assemblages derived from multiple sedimentary environments that display highly variable degrees of seafloor alteration may be signatures of modern cool-water carbonate assemblages worldwide. While such palimpsest sediments may complicate paleoenvironmental interpretation, their differentiation in the rock record can be utilized to discern subtleties in paleoceanography and sea-level history.
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 | 0,008 | 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 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,007 | 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 ».