Cr, Co and rare earth elements systematics in ice-rafted sediments of northern part of the Beaufort gyre
Notice bibliographique
Résumé
The results of analysis of the systematics of Cr, Co and rare earth elements (REE) in ice-rafted sediments (IRS) of the northern part of the Beaufort Cycle (Arctic Ocean) are considered in the article. The IRS was assembled on the ARK-XIV-1/a cruise of the NIS Polarstern in 1998. The exact position of the sources of the IRS present in the ice has not been established to date. This is due, on the one hand, to the complex ice cycle in the Arctic Basin, on the other - a relatively small amount of data on the actual composition of the IRS. According to the views of most researchers, the main IRS supplier is the wide and shallow Siberian Arctic shelf. In the Beaufort Sea, the distinctive features of which are a much narrower shelf and almost constant presence of ice in the summer period, the conditions for the formation of the IRS are not so favorable. The contents of rare and scattered elements in the IRS samples were determined with the help of INAA at GEOKHI RAS. As a result of the research it was established that variations (La/Yb)N in the IRS from the northern part of the Beaufort cycle are characterized by the values 8.5-15.5. They fully correspond to the average value of this parameter in the suspension of pp. Mackenzie and the Arctic-Red River (8.6 and 8.5) and the mean (La/Yb)N for the crystalline formations of the Canadian Shield (14.4). In the same range are included, the values of (La/Yb)N for the suspension of Yana and Lena rivers (8.7 and 12.4), which may indicate the possibility of the presence in the IRS of material borrowed on the shelf of the eastern Laptev Sea. In the Co-Cr diagram, there is no overlapping of the fields of the compositions of the present bottom sediments of the estuary of Yenisei River, on the one hand, and the eastern part of the East Siberian and Chukchi seas, on the other. Although the sediments of the delta of the Mackenzie River, comparable to the precipitation of the estuary of the Yenisei River. by the content of Cr and differ from them by a noticeably lower content of Co. In the Cr-La diagram, the IRS field occupies an essentially isolated position, yet still has a certain overlap with the precipitation fields of the Chukchi Sea and the delta of Mackenzie River. In the diagram (La/Yb)N-La/Co, the field of IRS composition has a ≈50% overlap with the field of the present bottom sediments composition of the Chukchi Sea. The middle point of the suspension also gravitates towards Lena River, and the point of the Canadian Shield is relatively close, as well as the points of suspension of Mackenzie and Arctic-Red rivers and PAAS. Overlapping of the IRS fields and modern bottom sediments of the Ob and Yenisei estuaries, as well as the east of the East Siberian Sea, on the contrary, is not observed. The data given in the article allow us to conclude that the IRS in the area of the North Pole contains sedimentary material, borrowed both on the shelf of the Beaufort Sea and on the shelves of the eastern part of the Laptev Sea and the Chukchi Sea.
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 | 0,003 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| 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) | 0,000 | 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 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 ».