Etude morphosédimentaire d’un remplissage endokarstique de la grotte du bois du clos (Charente, France) : contraintes géométriques et dynamiques hydrologiques
Bibliographic record
Abstract
Une coupe dans un remplissage détritique remarquable de plus de 5 m de hauteur, situé dans la grotte du Bois du Clos (karst de La Rochefoucauld, Charente) a permis une analyse morphosédimentaire d’une séquence discontinue et complexe. Trois grandes phases successives d’ennoyage/dénoyage de la cavité ont été mises en évidence par la combinaison d’une analyse granulométrique, des diagrammes de Passega, d’une analyse minéralogique des sables et des argiles et d’une analyse géochimique. Malgré l’absence de jalons chronologiques à l’intérieur de la séquence sédimentaire, une chronostratigraphie et un calage chronologique sont proposés grâce à une stalagmite qui scelle le remplissage et datée du stade isotopique marin 3. Les résultats sont corrélés avec des épisodes mis en évidence dans des sites voisins. Ils montrent dans notre cas le paléofonctionnement d’un système karstique d’abord ouvert et largement influencé par la fluctuation d’une grande nappe karstique (la Touvre) et par des écoulements proches (paléopertes), mais qui progressivement va se fermer. La question de l’interprétation paléoclimatique et paléoenvironnementale des sédiments est discutée. Les notions de piège karstique et de lacune sédimentaire sont développées. Les effets de site sur l’enregistrement sédimentaire des influences des variations climatiques sont ici mis en évidence. A section in a remarkable sequence of detrital deposits of more than 5 m high, filling in the cave of the Clos du Bois (La Rochefoucauld karst, Charente) allowed a morphosedimentary analysis of a discontinuous and complex sequence. Three major phases of submergence / dewatering of the cave have been identified by the combination of a grain-size analysis, Passega diagrams, a mineralogical analysis of sands and clays, and a geochemical analysis. Despite the lack of chronological milestones within the sedimentary sequence, a chronostratigraphy and time setting are proposed following the study of a stalagmite that seals the filling and is dated from marine isotopic stage 3. The results are correlated with episodes highlighted in nearby sites. They show in our case the palaeofunctioning of an initially open karst system heavily influenced by the fluctuation of a large karst water table (the Touvre) and by nearby flows (palaeostreams and palaeovadose flows), but gradually closing down. The palaeoclimatic and palaeoenvironmental interpretation of the sediments is discussed. Notions of endokarstic trap and sedimentary gap are developed. The “site effects” on the sedimentary record of the influences of climate variability are shown.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".