بررسي مس رگه اي شورك و زون گوسان همراه (شمال غرب بيرجند) بر اساس دگرساني، كاني سازي، زمين شيمي و سيالات درگير

Investigation of cu vein of the Shurk and associated gossan zone (North West of Birjand) based on alteration, mineralization, geochemistry and fluid inclusion

ﻣﺤــﺪوده ﺷــﻮرك ﺑﺨﺸــﯽ از ﭘﻬﻨــﻪ آﺗﺸﻔﺸــﺎﻧﯽ-ﻧﻔــﻮذي در ﺑﻠــﻮك ﻟــﻮت، ﺷــﻤﺎلﻏــﺮب ﺷــﻬﺮ ﺑﯿﺮﺟﻨــﺪ اﺳــﺖ. ﻃــﯽ ﭘــﯽﺟــﻮﯾﯽ اوﻟﯿــﻪ در اﯾــﻦ ﻣﻨﻄﻘــﻪ ﺗﻮﺳــﻂ ﭘـﺮدازش داده ﻫـﺎي ﻣـﺎﻫﻮاره اي آﺳـﺘﺮ ﺑــﻪ روش ﻧﻘﺸـﻪ ﺑـﺮدار ي زواﯾـﺎي ﻃﯿﻔــﯽ، دﮔﺮﺳـﺎﻧﯽ ﻫـﺎي ﭘﺮوﭘﻠﯿﺘﯿـﮏ، آرژﯾﻠﯿـﮏ و اﮐﺴــﯿﺪﻫ ﺎي آﻫـﻦ ﺑﺎرزﺳـﺎزي ﺷـﺪﻧﺪ . اﯾــﻦ ﮔﺴــﺘﺮه ﺷــﺎﻣﻞ ﺑﺮوﻧﺰدﻫــﺎﯾﯽ از ﺳــﻨﮓﻫــﺎي آﺗﺸﻔﺸــﺎﻧﯽ )ﺑــﺎ ﺗﺮﮐﯿــﺐ آﻧــﺪزﯾﺘﯽ ﺗــﺎ رﯾــﻮﻟﯿﺘﯽ( ﺑــﻮده ﮐــﻪ واﺣــﺪﻫــﺎي ﻧﯿﻤــﻪﻋﻤﯿــﻖ و ﻋﻤﯿــﻖ ﺑــﺎ ﺗﺮﮐﯿــﺐ ﮔــﺎﺑﺮوﯾﯽ ﺗــﺎ دﯾــﻮرﯾﺘﯽ در آﻧﻬــﺎ ﻧﻔــﻮذ ﻧﻤــﻮده اﻧــﺪ . ﮐــﺎﻧﯽ ﺳــﺎزي رﮔــﻪ اي در دو ﻣﺮﺣﻠــﻪ ﺷــﮑﻞ ﮔﺮﻓﺘــﻪ ﮐــﻪ ﺷــﺎﻣﻞ ، 1. ﮐــﻮارﺗﺰ -ﭘﯿﺮﯾــﺖ -ﮐﺎﻟﮑﻮﺳــﯿ ﺖ-ﮐﺎﻟﮑﻮﭘﯿﺮﯾــﺖ ﺑﻮرﻧﯿــﺖ±ﻓــﺎﻫﻠﻮر±اﺳــﻔﺎﻟﺮﯾﺖ ﻫﻤــﺮاه ﺑــﺎ دﮔﺮﺳــﺎﻧﯽ آرژﯾﻠﯿﮑــﯽ- ﺳﯿﻠﯿﺴــﯽ و 2. ﮐــﻮارﺗﺰ-ﮐﺎﻟﮑﻮﺳــﯿﺖ-ﮔــﺎﻟﻦ±اﺳــﻔﺎﻟﺮﯾﺖ ﻫﻤــﺮاه ﺑــﺎ دﮔﺮﺳــﺎﻧﯽ ﺳﯿﻠﯿﺴــﯽ -ﮐﺮﺑﻨــﺎﺗﯽ ﻣﯽﺑﺎﺷﺪ. ﻣﻄﺎﻟﻌﻪ ﺳـﯿﺎﻻت درﮔﯿـﺮ اوﻟﯿـﻪ در ﺑﻠﻮرﻫـﺎي ﮐـﻮارﺗﺰ ﻫﻤﺰﻣـﺎن ﺑـ ﺎ ﻣﺮﺣﻠـﻪ اول و دوم ﮐـﺎﻧﯽ ﺳـﺎزي رﮔـﻪ اي، ﻣﺘﻮﺳـﻂ دﻣـﺎي ﻫﻤﮕـﻦ ﺷـﺪن ﺑـﻪ ﺗﺮﺗﯿـﺐ 267 و 215 درﺟﻪ ﺳـﺎﻧﺘﯽ ﮔـﺮاد را ﻧﺸـﺎن ﻣـﯽ دﻫﻨـﺪ. ﺑـﺮ ﭘﺎﯾـﻪ ﻣﻄﺎﻟﻌـﺎت ﺳـﺮﻣﺎﯾﺶ، ﻣﯿـﺎﻧﮕﯿﻦ دﻣـﺎي ذوب آﺧـﺮﯾﻦ ﻗﻄﻌـﻪ ﯾـﺦ Tfmice در اﯾـﻦ دو ﻣﺮﺣﻠـﻪ ﺑـﻪ ﺗﺮﺗﯿـﺐ ﺑﺮاﺑــﺮ ﺑــﺎ 19/4 و 11/1 درﺻــﺪ وزﻧــﯽ ﻧﻤــﮏ ﻃﻌــﺎم اﺳــﺖ. اﺧــﺘﻼط، رﻗﯿــﻖ ﺷــﺪﮔﯽ ﺗﻮﺳــﻂ آبﻫــﺎي ﺟــﻮي و ﺟﻮﺷــﺶ ﻃــﯽ ﺗﺤــﻮل ﺳــﯿﺎﻻت ﮔﺮﻣــﺎﺑﯽ و ﺷــﮑﻞ-ﮔﯿﺮي رﮔﻪﻫـ ﺎ ﻣـﻮﺛﺮ ﺑـﻮده اﺳـﺖ. ﺑـﺮ ﭘﺎﯾـﻪ ﺷـﻮاﻫﺪ ي ﭼـﻮن ﮐﻨﺘـﺮل ﺳـﺎﺧﺘﺎري ﮐـﺎﻧﯽ ﺳـﺎزي، ﻧـﻮع دﮔﺮﺳـﺎﻧﯽ ، ﮐـﺎﻧﯽ ﺷﻨﺎﺳـﯽ ﺳـﺎده ذﺧﯿـﺮه و دادهﻫـﺎي دﻣﺎﺳـﻨﺠﯽ ﮐﺎﻧﺴﺎر ﺷﻮرك ﻣﺸﺎﺑﻪ ﮐﺎﻧﺴـﺎرﻫﺎي اﭘـﯽ ﺗﺮﻣـﺎل ﻣـﯽ ﺑﺎﺷـﺪ . ﺣﻀـﻮر ﻣﺘﻌـﺪد رﮔـﻪ ﻫـﺎي اﭘـﯽ ﺗﺮﻣـﺎل ﻣـﺲ در ﻣﻘﯿـﺎس وﺳـﯿﻊ ﻧﺸـﺎن دﻫﻨـﺪه ﭘﺘﺎﻧﺴـﯿﻞ اﻗﺘﺼـﺎدي ﺑـﺎﻻي اين محدوده مي باشد.

Recent studies concerning fluid evolution in magmatic-hydrothermal systems have mainly concentrated on porphyry copper and epithermal high-sulfidation Au-(Ag) deposits (Bethke et al., 2005; Einaudi et al., 2003; Fifarek and Rye, 2005; Heinrich, 2005). In contrast, less attention has been paid to associated epithermal base metal deposits which occur in the upper parts of the same environment and form later in the evolution of the system than the precious metal deposits (Baumgartner and Fontboté, 2008). The Shurk area is in the west of the Lut Block volcanic–plutonic belt, in eastern Iran, about 125 Km northwest of Birjand city. Great Tertiary, The Shurk area, is located in the west of the Lut Block volcanic–plutonic belt, in eastern Iran, about 125 Km northwest of Birjand city. The Tertiary magmatic activity in the Lut Block is spatially and temporally associated with several types of mineralization events (Karimpour et al., 2012). The prospecting area covers a significant part of the Lut Block that includes numerous cases of Cu±Pb±Zn vein-type mineralization, such as Shikasteh Sabz, Mir-e-Khash, Rashidi, Ghar-e-Kaftar, Howz-e-Dagh (Lotfi, 1982), as well as kaolin deposit (Cheshmeh Khuri area) in the neighboring area. Mineralization in the Shurk district generally described by Lotfi (1982) and Tarkian et al. (1983). Any author has published no minutiae study regarding fluid evolution and ore genesis at the Shurk district. We present and discuss geology, alteration, ore petrography, geochemistry, and fluid inclusion microthermometry, which help clarify the ore genesis of the Shurk area. 2-Material and methods Propylithic alterations, argillic alterations, and iron oxides were investigated during preliminary prospecting in the area using ASTER in the method of spectral angle mapper. The present study involved detailed fieldwork and study of thin sections and polished slabs from the igneous rocks and ore samples under the optical microscope. Metal concentrations were analyzed at IMPRC laboratory of Iran using ICP-OES techniques on 17 samples. Three samples were analyzed for Fire Assay analysis and seven samples for XRD analysis at IMPRC laboratory of Iran. Thirty-three spot analyses (microanalyses) were performed on an X-ray Analytical Microscope at IMPRC laboratory. Doubly polished wafers (150 μm thick) were prepared from five samples taken from surface and trenches. Microthermometric measurements were carried out using a Linkam THM 600 heating-freezing stage mounted on an Olympus TH4–200 microscope stage at the Ferdowsi University of Mashhad, Iran.