The study of crystal structure in the evolution of interstratified 2:1 clay minerals, Reindeer D-27 well, Mackenzie Delta - Beaufort Sea region, Arctic Canada /
Notice bibliographique
Résumé
Owing to the conflicting results obtained from the application of different analytical and sample preparation techniques, and to the complex nature of interstratified 2:1 clay minerals, the compositional and structural changes that occur with increasing diagenetic grade in illite-smectite (IS) mixed layers had not been adequately deciphered previously. Some of the uncertainties result from different modes of sample preparation, namely ion-beam milled original rock samples and dispersed separates. I have used a combined approach of n-alkylammonium cation exchange of 2:1 clay minerals, XRD, HRTEM, CTEM of Pt-C replicas of adsorbed and freeze-fractured specimens after cryofixation, and K-Ar dating is used to investigate nucleation and growth characteristics of 2:1 clay minerals from argillaceous rocks of the Reindeer D-27 well, Mackenzie Delta-Beaufort Sea (MDBS) region, Arctic Canada. In addition, three reference 2:1 clay minerals (Zempleni illite, rectorite, and Mancos Shale) were studied. Alkylamrnonium cation exchange of 2:1 clay minerals for investigation by XRD and TEM showed that the diagenetic evolution of smectite to illite in argillaceous rocks of the Reindeer D-27 well cannot be considered as a single, continuous and progressive reaction series as is conventionally proposed. It is rather a prograde sequence of discrete, multiple phases that coexist in overlapping depth intervals. K-Ar dating of illitic phases after treatment with octadecylammonium cations was undertaken to clarify the origin of octadecylammonium intercalated illite, account for its contribution to K-Ar ages, and assess the presence of detrital illitic phases in fine clay-size separates. Results suggested that K and Ar are removed to different degrees from both detrital and diagenetic components with treatment. By correlating the internal structure of the 2:1 clay minerals with the surface morphology, it was possible to show that the original stacking order of interstratified 2:1 clay minerals can be deciphered using dispersed separates, and that suitable techniques of sample preparation and dispersion can be employed to avoid disrupting the primary texture. In diagenetic samples from Reindeer D-27, the neoformed crystals have unique euhedral morphology, suggesting primary growth as free particles, rather than being disarticulated fragments of larger crystals, as proposed by the investigation of ion-milled specimens of original rock. Investigation of the reference samples of Zempleni illite, rectorite, and Mancos Shale showed that the original stacking order of the 2:1 clay minerals is not destroyed by sample preparation and dispersion. The results suggest that the concept of fundamental particles can be applied to illitic material formed in the early stages of diagenesis, but not necessarily to illitic material formed in other geologic environments such as hydrothermal and contact metamorphic environments. In addition, it was shown that the application of the technique of n-alkylammonium cation exchange for TEM is useful for the study of the evolution of S → I and isotopic dating of illitic clay minerals.
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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 | 0,000 |
| Études des sciences et des technologies | 0,001 | 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 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 ».