@article { author = {Maanijou, Mohammad and Mostaghimi, Mohammad and Abdollahy Riseh, Mehdi and Sepahi, Ali Asghar}, title = {Petrology and tectonic settings of the Sarcheshmeh porphyry copper deposit with emphasis on granodiorite and quartz eye porphyry}, journal = {Journal of Economic Geology}, volume = {12}, number = {3}, pages = {269-297}, year = {2020}, publisher = {Ferdowsi University of Mashhad}, issn = {2008-7306}, eissn = {2423-5865}, doi = {10.22067/econg.v12i3.80951}, abstract = {Introduction The Sarcheshmeh porphyry copper deposit (PCD) and other porphyry deposits occur in the the most important metallogenic belt in Iran, i.e. the Urumieh-Dokhtar magmatic belt (UDMB). The main phase of intrusion generation in various episodes of mineralization in the Sarcheshmeh area is a stock of granodiorite to tonalite (Shahabpour and Kramers, 1987) that is called the Sarcheshmeh porphyry. This stock intruded volcano-sedimentary rocks and alteration has centered on it. The oldest rock units of the area are Eocene volcanic rocks (Waterman and Hamilton, 1975), which are mainly andesites accompanying marine sedimentary rocks that is consistent with a submarine volcano-sedimentary basin environment. Granodiorite and quartz eye porphyry crop out in the northern part of the Sarcheshmeh PCD. The main objective of this study is to investigate their petrology and geotectonic environment.   Materials and Methods Forty samples from drill cores and surface samples from granodiorite and quartz eye porphyry were collected. Twelve samples were chosen with the lowest degree of alteration (less than 5% of representative samples and low LOI) from amongst them for lithogeochemical analyses by ICP-OES and ICP-MS. Lithogeochemical analysis of the main elements was carried out using ICP-OES (Inductively Coupled Plasma-Atomic Emission Spectroscopy) by lithiumborate fusion, and elemental analysis of trace and rare earth elements was performed by ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) using sodium peroxide fusion in the SGS Company, Toronto, Canada.   Results and Discussion Based on the Na2O+K2O versus SiO2 values on Cox et al. (1979) and Middlemost (1985) diagram, also R1-R2 diagram of De la Roche et al. (1980), the samples were plotted in the field of granodiorite and quartz diorite. On Harker diagrams, the contents of FeOt, CaO, p < sub>2O5, Al2O3, MgO, and TiO2 versus SiO2 show a decreasing pattern. Decreasing amounts of MgO and TiO2 can be related to early crystallization of ferromagnesian minerals and of CaO, Al2O3, and p < sub>2O5 to plagioclase and apatite crystallization, respectively. The chemical relationship and continuous pattern of the samples indicate that they probably resulted from fractionation of a unique magma. On the basis of the AFM diagram, they have calc-alkaline affinities. These observations and the presence of magnetite and other opaque minerals indicate high ƒO2 crystallization throughout fractionation stages. The samples of the study area were plotted in the calc-alkalic and alkali-calcic fields on a Frost et al. (2001) diagram and indicate that they are mainly magnesia consistent with oxidized I-type magmas. The spider-diagrams show negative anomalies in HFSE (especially Ti and Nb) and positive anomalies in LILE (especially in Ba and Rb). Negative anomalies of HFSE such as Ti, Nb, P and Ta can be related to the subduction of the Arabian plate under Central Iran and reflect the chemistry of the origin and crystallization-melting processes during evolution of the rocks. Moreover, it can be concluded that these elements remained in the source during partial melting, which is characteristics of I-type arc-related magmas. The behavior of LILE can be attributed to the behavior of fluid phases that were involved during the subduction. The REE diagrams show enrichment of LREE relative to HREE which can also be attributed to the subduction of the Arabian plate under Central Iran. Shafiei et al. (2009) and Asadi, 2018 proposed post-collision environment for the PCDs of the UDMB, especially in the Kerman part. By studying on the Dehaj-Sarduieh belt, Dargahi et al. (2010) concluded that the time of collision of the Arabian plate and the Central Iran continental plate was Late Eocene, and the Sarcheshmeh porphyry stock emplaced in post-orogenic environment like other stock porphyries of the UDMB. The samples of the Sarcheshmeh PCD plot in the mature arc area based on Rb vs Y+Nb diagram and it can be envisaged that they are related to the post-collision magmatic arc.   References Asadi, S., 2018. Triggers for the generation of post–collisional porphyry Cu systems in the Kerman magmatic copper belt, Iran: New constraints from elemental and isotopic (Sr-Nd-Hf-O) data. Gondwana Research, 64(12): 97–121. Dargahi, S., Arvin, M., Pan, Y. and Babaei, A., 2010. Petrogenesis of post-collisional A-type granitoids from the Urumieh-Dokhtar magmatic assemblage, southwestern Kerman, Iran: Constraints on the Arabian-Eurasian continental collision. Lithos, 115(1–4): 190–204. Shafiei, B., Haschke, M. and Shahabpour, J., 2009. Recycling of orogenic arc crust triggers porphyry Cu mineralization in Kerman Cenozoic arc rocks, southeastern Iran. Mineralium Deposita, 44(3): 265–283. Shahabpour, J. and Kramers, J.D., 1987. Lead isotope data from the Sarcheshmeh porphyry copper deposit, Kerman, Iran. Mineralium Deposita, 22(4): 278–281. Waterman, G.C. and Hamilton R., 1975. The Sarcheshmeh porphyry copper deposit. Economic Geology 70(3): 568–576.}, keywords = {Sarcheshmeh porphyry copper deposit,Granodiorite,Quartz eye porphyry,subduction,post-collision area}, title_fa = {بررسی سنگ شناسی و جایگاه زمین‌ساختی کانسار مس پورفیری سرچشمه، با تأکید بر گرانودیوریت و کوارتز چشمی پورفیری}, abstract_fa = {کانسار مس پورفیری سرچشمه در بخش جنوب‌شرقی کمربند ارومیه-دختر و در کمربند دهج-ساردوئیه واقع‌شده است. این کمربند با روند شمال­‌غربی-جنوب­‌شرقی در استان کرمان واقع‌شده و بیشترین حجم ماگماتیسم و نیز کانی­‌سازی پورفیری را به خود اختصاص داده است. رخنمون­‌های سنگی در محدوده­ معدن شامل استوک گرانودیوریتی سرچشمه و پورفیری دانه‌­ریز تأخیری، توده‌­های نفوذی گرانودیوریتی و کوارتز چشمی پورفیری، ولکانیت­‎ها یا سنگ میزبان آندزیتی و دایک­‌های هورنبلند پورفیری، بیوتیت پورفیری و فلدسپـار پورفیری با ترکیب دیوریتی است. همچنین توده‌­های نفوذی گرانودیوریتی و کوارتز چشمی پورفیری پیش از توده‌­های نفوذی کانی­‌ساز (از جمله سرچشمه پورفیری و پورفیری دانه­‌ریز تأخیری) تزریق شده­‌اند. بر اساس بررسی‌های سنگ‌­شناسی و ژئوشیمیایی، توده‌­های نفوذی گرانودیوریتی و کوارتز چشمی پورفیری در محدوده­ سنگ­‌های گرانودیوریتــی حاصل از یک ماگمـــای کالک‌­آلکالن قرار می­‌گیرند و لذا توده­‌های نفوذی مورد بررسی از نوع پرآلومینوس و پتاسیم بالا هستند. غنی‌­شدگی عناصر LREE نسبت به HREE و عناصر LILE نسبت به HFSE‌، تشکیل ماگما را در پهنه­ فرورانشی تأیید می­‌کند؛ همچنین نسبت­‌های عناصر نادر خاکــی و کمیاب (از جمله: Ba/Nb، Ba/Ta، Sr/Y و ...) بیانگر آن است که این توده‌­های نفوذی در یک پهنه­ فرورانشی و از یک کمان ماگمایی غنی‌شده حاصل شده‌­اند که این غنی­‌شدگی می‌­تواند ناشی از متاسوماتیسم شدید منبع گوشته‌­ای با میزان پایین ذوب‌بخشی محل منشأ و آلودگی ماگما با مواد پوسته‌­ای و همچنین ماگماهای کالک‌­آلکالن حاصل از میزان زیاد ذوب‌بخشی یا حاصل ذوب‌بخشی پوسته اقیانوسی نئوتتیس باشد. محیط زمین‌ساختی کانسار سرچشمه و توده‌­های مورد بررسی، بیانگر یک محیط پس از بــرخوردی است که کانی­‌سازی در آن صورت‌گرفته است.}, keywords_fa = {کانسار مس پورفیری سرچشمه,گرانودیوریت,کوارتز چشمی پورفیری,فرورانش,محیط پس از برخوردی}, url = {https://econg.um.ac.ir/article_39292.html}, eprint = {https://econg.um.ac.ir/article_39292_8026741ea40b3d96ea92230468c331a8.pdf} }