In-situ trace element and sulfur isotope analyses of sulfides as indicators of ore-forming fluid evolution in the Lakang’e porphyry Mo-Cu deposit, Tibet, China
Notice bibliographique
Résumé
• Lakang’e deposit shows at least four mineralization hydrothermal pulses (A, B1, B2, D). • Magnetite crystallization and the influx of meteoric water are the primary causes of f O 2 changes in the different veins. • Mo precipitation is primarily controlled by temperature and f O 2 , while Cu precipitation is mainly driven by temperature drease. The Lakang’e Mo-Cu deposit is a Mo-dominated porphyry deposit located in the Gangdese metallogenic belt of southern Tibet, which is known for Cu-dominated porphyry deposits such as Jiama and Qulong. The magmatic-hydrothermal evolution responsible for the development of ore-forming fluids in this deposit has not been systematically examined, thus limiting our understanding of the genetic link between Cu and Mo mineralization throughout the metallogenic belt. This study addresses this problem through in-situ analysis of S isotopes and trace elements of pyrite, chalcopyrite and molybdenite from hydrothermal veins of different stages (A, B1, B2, D), which reflect the evolution of the hydrothermal system in terms of S source and temperature, pH and redox condition. The overall range of δ 34 S CDT values (–7.68 ‰ to +0.75 ‰) of the sulfides and the lack of systematic variation from one stage to another are consistent with a common magmatic source for the sulfur. The decrease of Co/Ni ratios in pyrite from A and B1 to B2 and D veins indicates an overall cooling trend. The elevated As concentrations in sulfides and the lack of calcite in A and B1 veins versus the relatively low As in sulfides and presence of calcite in the D and B2 veins suggest that the fluids became less acidic from early to late stages. The relatively elevated Te concentration in pyrite in B1 and B2 veins compared to those in A and D veins suggests that B1 and B2 veins formed under relatively reducing conditions, whereas A and D veins formed under relatively oxidizing conditions. The consumption of Fe 3+ due to precipitation of large amounts of magnetite in A vein may be responsible for the decrease in f O 2 , which induced significant Mo mineralization in B1 veins. As the hydrothermal system continued to evolve with decreasing temperature and increasing influx of meteoric water, the f O 2 increased again, which promoted the precipitation of pyrite-chalcopyrite instead of molybdenite in the D veins. At last, another phase of distinct Mo mineralization may have been triggered by the release of residual metalliferous fluids from a dormant magma chamber due to tectonic reactivation, subsequently migrating upward and forming the B2 veins. Our study highlights the dynamic evolution of magmatic-hydrothermal fluids during the formation of the Lakang’e Mo–Cu deposit and demonstrates that fluid temperature, oxygen fugacity ( f O 2 ), and the involvement of meteoric water were the primary controls on mineralization. Molybdenite precipitation in the B1 and B2 veins was driven by decreasing temperature and f O 2 , whereas chalcopyrite precipitation in the D vein was triggered by fluid cooling due to mixing with meteoric water. Such dynamic magmatic-hydrothermal processes may have also operated in other Cu-Mo deposits within the Gangdese metallogenic belt, implying that separate episodes of Mo-dominated mineralization may have been potentially developed in the Cu-dominated deposits as well.
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 | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,001 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| 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 ».