DOI: 10.1007/s00531-012-0819-7
Scopus记录号: 2-s2.0-84875471521
论文题名: The alteration, mineralogy and geochronology (SHRIMP U-Pb and 40Ar/39Ar) of copper-bearing Anjerd skarn, north of the Shayvar Mountain, NW Iran
作者: Hassanpour S.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2013
卷: 102, 期: 3 起始页码: 687
结束页码: 699
语种: 英语
英文关键词: 40Ar/39Ar
; Anjerd
; Copper-bearing skarn
; Metasomatic alterations
; NW Iran
; Shayvar
; SHRIMP
Scopus关键词: argon-argon dating
; batholith
; geochronology
; igneous intrusion
; low temperature
; metasomatism
; mineralization
; mineralogy
; pluton
; retrograde metamorphism
; SHRIMP dating
; skarn
; solidification
; Ahar
; East Azerbaijan
; Iran
; Decapoda (Crustacea)
英文摘要: A Cu-bearing skarn zone occurs north of the Shayvar Mountain in northwestern Iran. Skarn-type metasomatic alteration and mineralization occur along the contact between Upper Cretaceous impure carbonates and a Miocene Cu-bearing granitic stock. Both endoskarn and exoskarn developed in the rocks. Exoskarn is the principal skarn zone and is enclosed by a skarnoid-hornfelsic zone. Skarn formation occured during stages: (1) prograde, (2) middle stage and (3) late stage. In the prograde stage, there were two main processes: (a) metamorphic-bimetasomatic and (b) prograde metasomatic. The metamorphic process began immediately after intrusion of the pluton into the enclosing impure carbonates. The prograde metasomatic stage commenced with segregation and evolution of a fluid phase in the pluton and movement into fractures and micro-fractures in the skarnoid-hornfelsic rocks developed in a metamorphic zone. The introduction of considerable amounts of Fe, Si and Mg led to the development of voluminous medium- to coarse-grained anhydrous calc-silicates. During the middle stage, the previously formed skarn zones were affected by intense multiple hydrofracturing in the Cu-bearing stock. In addition to Fe, Si and Mg, substantial amounts of Cu, Pb and Zn, along with volatile components such as H2S and CO2 were added to the skarn system. Consequently, substantial amounts of hydrous calc-silicates (epidote, tremolite-actinolite), sulfides (pyrite, chalcopyrite and molybdenite), oxides (magnetite, hematite) and carbonates (calcite) replaced the anhydrous calc-silicates. The retrograde stage was synchronous with the incursion of relatively low-temperature, more oxidized fluids into skarn system, resulting in partial alteration of the early-formed calc-silicates and development of a series of very fine-grained aggregates of chlorite, clay, hematite and calcite. Zircon grains from the endoskarn zone provide constraints on the timing of solidification of the granite stock (9. 91 ± 0. 31 Ma) that caused mineralization in the Anjerd area. One sample of primary hornblende from the monzogranitic Shayvar batholith has an 40Ar/39Ar age of 26. 54 ± 0. 65 Ma and indicates that intrusion of the Miocene stock and associated Cu skarn formation occurred a considerable time after intrusion of the batholith. © 2012 Springer-Verlag. URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84875471521&doi=10.1007%2fs00531-012-0819-7&partnerID=40&md5=cebf2cc42f373d89c678706c5c5dffe8
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70586
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Geology, Payame Noor University, Tehran, Iran
Recommended Citation:
Hassanpour S.. The alteration, mineralogy and geochronology (SHRIMP U-Pb and 40Ar/39Ar) of copper-bearing Anjerd skarn, north of the Shayvar Mountain, NW Iran[J]. International Journal of Earth Sciences,2013-01-01,102(3)