Anatomy of a Moderately Telescoped Porphyry–High-Sulfidation System: Insights of a 2 km Vertical Profile of Alteration and Mineralization at Valeriano Cu-Au ± Mo Deposit, Chile
Notice bibliographique
Résumé
Abstract The Valeriano Cu-Au ± Mo deposit is located at the northern end of the El Indio metallogenic belt in the Chilean Central Andes, a region well-known for its prolific Au-Ag high-sulfidation epithermal deposits. In the past decade, deep drilling beneath the Valeriano lithocap resulted in the discovery of a concealed Cu-Au ± Mo porphyry system at depth, providing insights into a 2-km vertical profile of alteration from the shallow high-sulfidation epithermal to the porphyry environment. The Valeriano system is dominantly hosted in early Permian to Late Triassic felsic volcaniclastic rocks, and near the surface, by Middle Miocene intermediate composition volcanic rocks. Porphyry-style mineralization was temporally and spatially associated with the emplacement of a series of hornblende-biotite-bearing porphyries of granodioritic composition, and related magmatic-hydrothermal breccias between 10.39 ± 0.19 and 10.12 ± 0.18 Ma, based on zircon U-Pb ages. These intrusions and breccias at depth (>1,000 m below the present-day surface) are associated with Cu-Au mineralization of chalcopyrite and lesser bornite and molybdenite coupled with K-silicate alteration, which formed between 10.55 ± 0.05 and 10.1 ± 0.04 Ma, as determined by molybdenite Re-Os dating. K-silicate alteration is pervasively overprinted by muscovite-quartz ± chlorite alteration containing chalcopyrite and pyrite. This assemblage transitions upward over a distance of ~400 m into a 400- to 750-m-thick zone of muscovite-quartz ± pyrophyllite at the base of the lithocap that is intimately associated with low-grade, high-sulfidation state Cu sulfides and Cu-As sulfosalts dominated by bornite, digenite, chalcocite, and minor covellite. The upper part of the lithocap consists of a 100- to 200-m-thick, concentrically zoned, advanced argillic alteration—characterized by different proportions of quartz, alunite, kaolinite, and pyrophyllite—centered on stratiform or structurally controlled zones of massive and vuggy quartz. These zones host discrete Au-bearing enargite epithermal mineralization, which occurs as hydrothermal breccias, veins, and open-space fillings, which seem to be the remnants of a larger eroded high-sulfidation system. Muscovite and alunite Ar-Ar ages from zones of white mica and advanced argillic alteration, respectively, yielded ages between 10.151 ± 0.024 and 10.038 ± 0.014 that overlap with the age of porphyry intrusion and associated mineralization, suggesting that porphyry and epithermal mineralization at Valeriano formed over a short period of between 690 and 510 k.y. Advanced argillic alteration transitions outward and upward to intermediate argillic alteration over a distance of 200 to 500 m, which in turn transitions sharply into weakly altered to unaltered rocks in the uppermost lateral portion of the system, suggesting that the Valeriano lithocap was partially blind.
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 | 0,000 | 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 | 0,000 |
| 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) | 0,001 | 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 ».