Mineralization and hydrothermal alteration of the Tajroud vein system, south of Neyshabour

Journal of Economic Geology

Mohsen Alikhani Banghani¹  Gholam Hosein Shamanian¹  Mohammad Jafari Zanglanlou² 

[1]Department of Geology, Faculty of Sciences, Golestan University, Gorgan, Iran

[2]Geological Survey of Iran (Northeast Territory), Mashhad, Iran

关键词: Epithermal;    Hydrothermal alteration;    Alteration index;    Low-sulfidation;    Tajroud;   

DOI  :  

来源: DOAJ

【 摘 要 】

The Tajroud vein system is located 190 km southwest of Mashhad, and in the southern part of the Sabzevar zone. The vein host rocks consist of Eocene intermediate to silicic volcanic rocks. The mineralization occurs as open space filling, taking place as veins, veinlets and hydrothermal breccias. Based on field geology and textural evidence, three main stages of mineralization were identified. Stage I mainly contains quartz, pyrite, chalcopyrite and magnetite. Stage II, which has the same mineral assemblage as stage I, is the most important stage in terms of volume. Finally, stage III is characterized by repetitive quartz and calcite banding with negligible amounts of sulfide minerals. Hydrothermal alteration is developed around the veins and tends to be more intense in the vicinity of the veins. The plot of the Ishikawa alteration index (AI) versus chlorite-carbonate-pyrite index (CCPI), known as alteration box plot, displays three main alteration trends. The hydrothermal alteration assemblage of quartz, adularia, chlorite, illite, calcite, and epidote that envelops the Tajroud vein system formed from the upwelling of near-neutral to weakly alkaline hydrothermal solutions. The mineralogic, alteration and geochemical characteristics of the studied area and comparison with epithermal ore deposits indicate that the Tajroud vein system represents an epithermal system of low-sulfidation type.

【 授权许可】

Unknown