The relationship between lamprophyre dykes and ore deposits with special reference to British Columbia
Notice bibliographique
Résumé
Some conceptions by Bowen regarding the processes apparently involved in the formation of ultra-basic lamprophyres have been applied to observations made on reaction-rims in the rocks of this thesis. An attempt has been made to find, in the reaction-rims surrounding basic minerals, phenomena that might indicate that reactions took place, during the time the rock was forming, between the basic minerals and an alkaline liquid. No conclusive evidence of such reactions was found but the suggestion is made that there is an unusually great development of reaction rims, especially in the more basic lamprophyres, that may be due to the effect of an alkaline liquid. Another theory by Bowen, dealing with the possible origin of ore-bearing solutions, has been amplified to present possible reasons for a close relation between lamprophyres and ore. On the more practical side, a petrographic study of lamprophyres and associated ore has revealed an intra-mineralization age for lamprophyres whose field relations do not conclusively indicate contemporaneity with ore. A compilation from the literature, of facts pertaining to most of the lamprophyre occurrences in British Columbia, has provided interesting statistics on the geographical and geological distribution of lamprophyres, and on their relations to different types of ore. The majority of lamprophyres occur in the Rossland-Ymir-Nelson-Slocan belt, near the eastern contact of the Nelson series of batholiths, while most of the remainder are confined to the eastern contact of the Coast Range batholith. The lamprophyres of the Nelson batholith region are associated with ores which, in the Rossland, Salmo, Ymir and Nelson areas are almost half of the Pb, Zn, Ag type and in the Ainsworth-Slocan districts, entirely of the Pb, Zn, Ag type. It is in the Ainsworth-Slocan districts furthermore, that lamprophyres are perhaps most densely concentrated and show the closest time relation to ore. The lamprophyres along the east-side of the Coast Range batholith provide most of the evidence indicating that post-ore lamprophyres are predominantly associated with ores containing Au and Cu. The conclusion seems inescapable that lamprophyres are concentrated in the two most intensely mineralized zones of the province. Furthermore, a marked affinity is shown by lamprophyres for those areas in which Pb, Zn, Ag mineralization either is prominent or, at least, is present along with other metals. These statistical facts suggest that the relation between ore and lamprophyres is not purely one of chance and they arouse our curiosity as to what reasons may exist for such a relationship.
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 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,006 | 0,007 |
| Études des sciences et des technologies | 0,004 | 0,001 |
| Communication savante | 0,002 | 0,000 |
| Science ouverte | 0,001 | 0,001 |
| 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 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 ».