Document Type : Original Research Paper

Authors

1 Department of Geology, Faculty of Science, Islamic-Azad University, Science & Research Campus, Tehran, Iran

2 Department of Geology, Earth Sciences Faculty, Shahid Beheshti University, Tehran, Iran

3 Research Institute for Earth Sciences, Geological Survey of Iran, Tehran, Iran

Abstract

The Masjeddaghi area is a part of Alborz-Azarbaijan Zone and located in the Jolfa 1:100000 geological map sheet. The oldest rock units cropped out widely in the south and northeast of the area belong to the Eocene flysch-type sediments. The other outcrops consist mainly of volcanic rock complex of andesites and trachyandesites affected by quartz monzonite intrusion and caused alteration of phyllic and carbonate phyllic type. The mineralization in volcanic complex is also accompanied by quartz and barite veins. The study of alterated zone around veins shows sericite, silicified, prophillitic, chloritic and alunite (jarosite) alterations. Investigation of alteration zones around mineralized veins shows epithermal gold ore in which alunitic alteration (jarocite) is the most important characteristics. The result of the study on alteration and extension of altered zones in the whole study area give rise to the probability of porphyry type copper deposit (potassic, phyllic, argillic and prophylitic alteration zone).

Keywords

References                                                                                                                                    
Berberian, M., King, G.C.P., 1981- Toward a Paleogeogrphy and tectonic  evolution of Iran , Canadian journal of Earth Seciences , Vol  18 , No  2, PP: 210-265.
Eftekhar -Nezhad, J.,1975- Brief history and structural development of  Azarbaijan , G , S , I , Internal rep , N , 8.
Middlemost, E.A.K.,1991-Toward a Comprehensive clssification of igneous rocks and magmas, Earth Sci, No –31, PP:73 –87.
Hall, A., 1992- Igneous Petrology , Longman  S , & T,P: 24 – 291.
Takagi, T. & Tsakimura, K., 1997 - Genesis of oxidized and reduced type granites , Es , Geol , Vol- 92 , PP – 91.
Hezarkhani, A. & Williams-Jones, A.E., 1998- Control of alterational and mineralization in the Sungun porphyry deposit, Iran: Evidence . from fluid inclusions and stable isotpes Econ – geol , Vol. 93 , PP : 651 – 640.
Mehrpartou, M.,1993- Contribution to the geology, geochemistry Ore genesis and fluid inclusion investigation on Sungun Cu – Mo Porphyry deposit (Northwest Iran ) , Hambury University.
Zoto, A.  U., Kudrin, A.V., Levin , K.A., Shikina, N.D. & Varyash, L. N., 1992- Eperimental studies of the slubility and Complexing of selected ore element ( Au , Ag , Mo , As , Sb , Mg ) in agueous solution.
Ridley, J. et al., 1996- Ore Geology Reuies 10 , PP : 279 – 293.
Muller, D. & Gross , D. A., 1996- Might Potassium rocks with gold copper mineralization.
Hayshi, K. I. & Ohmoto, H., 1991- Solubilty of gold in Nach – and H2S . bearing Solution at 250 – 350 ° C , Geichimica at Cos mochimica Acta Vol . 55 , 2111 – 2126.