{"title":"圣佩德罗斑岩型铜(钼)矿床岩浆-热液演化:对冈瓦纳西缘二叠纪岩浆成矿作用的启示","authors":"A. Gómez, T. Ulrich, N. Rubinstein","doi":"10.1111/rge.12251","DOIUrl":null,"url":null,"abstract":"The San Pedro porphyry Cu‐(Mo) deposit, located in the San Rafael Massif (Argentina), is characterized by multiple stockwork vein generations developed in a subvolcanic intrusion with porphyry‐type alteration and mineralization, as well as associated polymetallic veins. Previous works reveal that the intrusive rocks related to the San Pedro porphyry (263 Ma) show comparable trace element signatures to giant porphyry deposits elsewhere (i.e., high Sr/Y and low Y). The fluid inclusions investigated in this study show that typical early, high‐temperature magmatic fluids (up to 685°C; 81.3 wt% equiv. NaCl) evolved to lower‐temperature, moderately saline fluids (up to 454°C; 52.4 wt% equiv. NaCl) due to fluid–rock interaction. The waning stage of the system is characterized by secondary, aqueous inclusions that represent dilution by meteoric fluids (up to 390°C, 16.9 wt% equiv. NaCl). Fluid inclusions were studied from two veinlet generations (A and B veinlets) related to potassic alteration and analyzed by LA‐ICP‐MS. The trace element signatures in the fluid inclusions suggest that there were two pulses of magmatic fluids that subsequently evolved under similar physicochemical conditions. The Cu concentration in the earliest fluid is between 0.3 and 0.85 wt% and within the concentrations found in other mineralized porphyry systems in the world. However, in contrast to economic porphyry systems, where a significant change in Cu concentration during fluid evolution is observed, there is no distinct change in the fluid Cu concentration at the San Pedro deposit, which would indicate that Cu and Mo precipitation was ineffective in the hydrothermal system.","PeriodicalId":21089,"journal":{"name":"Resource Geology","volume":null,"pages":null},"PeriodicalIF":1.1000,"publicationDate":"2021-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"4","resultStr":"{\"title\":\"The magmatic–hydrothermal evolution of the San Pedro porphyry Cu‐(Mo) deposit: Implications for the metallogenesis of the Permian magmatism in the western margin of Gondwana\",\"authors\":\"A. Gómez, T. Ulrich, N. Rubinstein\",\"doi\":\"10.1111/rge.12251\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The San Pedro porphyry Cu‐(Mo) deposit, located in the San Rafael Massif (Argentina), is characterized by multiple stockwork vein generations developed in a subvolcanic intrusion with porphyry‐type alteration and mineralization, as well as associated polymetallic veins. Previous works reveal that the intrusive rocks related to the San Pedro porphyry (263 Ma) show comparable trace element signatures to giant porphyry deposits elsewhere (i.e., high Sr/Y and low Y). The fluid inclusions investigated in this study show that typical early, high‐temperature magmatic fluids (up to 685°C; 81.3 wt% equiv. NaCl) evolved to lower‐temperature, moderately saline fluids (up to 454°C; 52.4 wt% equiv. NaCl) due to fluid–rock interaction. The waning stage of the system is characterized by secondary, aqueous inclusions that represent dilution by meteoric fluids (up to 390°C, 16.9 wt% equiv. NaCl). Fluid inclusions were studied from two veinlet generations (A and B veinlets) related to potassic alteration and analyzed by LA‐ICP‐MS. The trace element signatures in the fluid inclusions suggest that there were two pulses of magmatic fluids that subsequently evolved under similar physicochemical conditions. The Cu concentration in the earliest fluid is between 0.3 and 0.85 wt% and within the concentrations found in other mineralized porphyry systems in the world. However, in contrast to economic porphyry systems, where a significant change in Cu concentration during fluid evolution is observed, there is no distinct change in the fluid Cu concentration at the San Pedro deposit, which would indicate that Cu and Mo precipitation was ineffective in the hydrothermal system.\",\"PeriodicalId\":21089,\"journal\":{\"name\":\"Resource Geology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.1000,\"publicationDate\":\"2021-01-14\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"4\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Resource Geology\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1111/rge.12251\",\"RegionNum\":4,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOLOGY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Resource Geology","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1111/rge.12251","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOLOGY","Score":null,"Total":0}
The magmatic–hydrothermal evolution of the San Pedro porphyry Cu‐(Mo) deposit: Implications for the metallogenesis of the Permian magmatism in the western margin of Gondwana
The San Pedro porphyry Cu‐(Mo) deposit, located in the San Rafael Massif (Argentina), is characterized by multiple stockwork vein generations developed in a subvolcanic intrusion with porphyry‐type alteration and mineralization, as well as associated polymetallic veins. Previous works reveal that the intrusive rocks related to the San Pedro porphyry (263 Ma) show comparable trace element signatures to giant porphyry deposits elsewhere (i.e., high Sr/Y and low Y). The fluid inclusions investigated in this study show that typical early, high‐temperature magmatic fluids (up to 685°C; 81.3 wt% equiv. NaCl) evolved to lower‐temperature, moderately saline fluids (up to 454°C; 52.4 wt% equiv. NaCl) due to fluid–rock interaction. The waning stage of the system is characterized by secondary, aqueous inclusions that represent dilution by meteoric fluids (up to 390°C, 16.9 wt% equiv. NaCl). Fluid inclusions were studied from two veinlet generations (A and B veinlets) related to potassic alteration and analyzed by LA‐ICP‐MS. The trace element signatures in the fluid inclusions suggest that there were two pulses of magmatic fluids that subsequently evolved under similar physicochemical conditions. The Cu concentration in the earliest fluid is between 0.3 and 0.85 wt% and within the concentrations found in other mineralized porphyry systems in the world. However, in contrast to economic porphyry systems, where a significant change in Cu concentration during fluid evolution is observed, there is no distinct change in the fluid Cu concentration at the San Pedro deposit, which would indicate that Cu and Mo precipitation was ineffective in the hydrothermal system.
期刊介绍:
Resource Geology is an international journal focusing on economic geology, geochemistry and environmental geology. Its purpose is to contribute to the promotion of earth sciences related to metallic and non-metallic mineral deposits mainly in Asia, Oceania and the Circum-Pacific region, although other parts of the world are also considered.
Launched in 1998 by the Society for Resource Geology, the journal is published quarterly in English, making it more accessible to the international geological community. The journal publishes high quality papers of interest to those engaged in research and exploration of mineral deposits.