Advances and its diagnostic criteria in the study of the reduced porphyry ore deposits in China
文献类型：期刊论文
| 作者 | Ping, Shen1,2,4; Pan HongDi3 |
| 刊名 | ACTA PETROLOGICA SINICA
 |
| 出版日期 | 2020 |
| 卷号 | 36期号:4页码:967-994 |
| 关键词 | Reduced porphyry ore deposit Reduced ore forming fluid CH4 source Ilmenite Diagnostic criteria |
| ISSN号 | 1000-0569 |
| DOI | 10.18654/1000-0569/2020.04.01 |
| 英文摘要 | Most porphyry ore deposits worldwide have fluid inclusions with CO2 >> CH4 that are indicative of high oxygen fugacity (f(O2)). However, Rowins (2000) proposed that some porphyry Cu-Au deposits lack primary hematite, magnetite and anhydrite, but contain abundant hypogene pyrrhotite, which commonly have carbonic-rich ore fluids with substantial CH4. These porphyry Cu-Au deposits, associated with ilmenite-bearing, reduced I-type granitoids, are small in size, and are called the reduced porphyry Cu-Au deposits. Recently, Chinese scholars recognized the reduced porphyry-skarn Cu deposits and the reduced porphyry Mo deposits besides the reduced porphyry Cu deposits in China. We named all of them as the reduced porphyry ore deposits. Based on lots of investigations and studies in recent ten years done by the authors, combined with the previous researches, this paper tentatively makes a comprehensive elucidation of typical reduced porphyry deposits in China and focuses on the characteristics of large reduced porphyry deposits and their wall rocks, the source of CH4 in the ore-forming fluid and related mineralization, the redox state of the ore-forming magmas and its genesis, and the metallogenic tectonic setting. Unlike the small-size reduced porphyry Cu deposits proposed by Rowins (2000), many reduced porphyry deposits in China are large-size. Our study also identified some unusual hydrothermal alteration and metallogenic characteristics. For example, the hydrothermal alteration of the reduced porphyry Cu deposit is characterized by predominant ilmenization rather than magnetization and its ore minerals are chalcopyrite with rare bornite, chalcocite; the hydrothermal alteration of the reduced porphyry Mo deposit occurs ilmenization and its ore minerals is molybdenite, without wolframite and cassiterite. The reduced porphyry-skarn Cu deposits are marked by a reduced skarn mineralogy (e.g. hessonite and hedenbergite) and abundant pyrrhotite in the skarn stage and by major chalcopyrite rather than bornite and chalcocite in the hydrothermal stage. The diagnostic criteria of reduced porphyry deposits, therefore, also includes the criteria of unique gangue minerals (e.g. ilmenite, hessonite and hedenbergite) and simple ore minerals (e.g. chalcopyrite, molybdenite) besides the marks (e.g. CH4-rich fluid and abundant pyrrhotite) proposed by Rrowins (2000). Generally, the porphyry ore deposits exposes reductive strata (e.g. carbon-bearing sedimentray rocks, ferrous-bearing mafic volcanic rocks) where the mineralized porphyry intruded. There are different opinions about the origin of CH4 in ore-forming fluid. Most scholars believe that major CH4 is derived from reductive wall rocks and minor from magma. The oxidation state of the most mineralized intrusions has not been identified or is controversial. Most scholars propose that the primary magma was oxidized magma but with relatively low oxygen fugacity (f(O2)). Minor suggests that the magma was always reduced magma. As far as the tectonic setting was concerned, it is similar between the reduced porphyry deposits in China and typical porphyry deposit in the world. The reductive characteristics of the reduced porphyry deposits in China are closely related to the CH4-bearing ore-forming fluid, which is the key to the formation of reduced porphyry deposits. |
| WOS关键词 | CU-AU DEPOSIT ; COPPER-MOLYBDENUM DEPOSIT ; WEST JUNGGAR TERRAIN ; U-PB GEOCHRONOLOGY ; MO DEPOSIT ; FLUID INCLUSIONS ; INNER-MONGOLIA ; EASTERN TIANSHAN ; GEOLOGICAL CHARACTERISTICS ; MINERALIZATION FLUID |
| WOS研究方向 | Geology |
| 语种 | 英语 |
| WOS记录号 | WOS:000534690600001 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/96666]  |
| 专题 | 地质与地球物理研究所_中国科学院矿产资源研究重点实验室 |
| 通讯作者 | Ping, Shen |
| 作者单位 | 1.Chinese Acad Sci, Innovat Acad Earth Sci, Beijing 100029, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Mineral Resources, Beijing 100029, Peoples R China 3.Changan Univ, Coll Earth Sci, Xian 710054, Peoples R China 4.Univ Chinese Acad Sci, Beijing 100049, Peoples R China |
| 推荐引用方式 GB/T 7714 | Ping, Shen,Pan HongDi. Advances and its diagnostic criteria in the study of the reduced porphyry ore deposits in China[J]. ACTA PETROLOGICA SINICA,2020,36(4):967-994. |
| APA | Ping, Shen,&Pan HongDi.(2020).Advances and its diagnostic criteria in the study of the reduced porphyry ore deposits in China.ACTA PETROLOGICA SINICA,36(4),967-994. |
| MLA | Ping, Shen,et al."Advances and its diagnostic criteria in the study of the reduced porphyry ore deposits in China".ACTA PETROLOGICA SINICA 36.4(2020):967-994. |
入库方式： OAI收割
来源：地质与地球物理研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。