@article { author = {Bikdeli, Z and Ebrahimi, M and Nabatian, Gh and Nabatian, M.A.A}, title = {Mineralization, Mineralogy, Structure and Texture of Chehrabad Sedimentary Cu Deposit, Northwest of Zanjan}, journal = {Scientific Quarterly Journal of Geosciences}, volume = {24}, number = {96}, pages = {249-262}, year = {2015}, publisher = {Geological Survey of Iran}, issn = {1023-7429}, eissn = {2645-4963}, doi = {10.22071/gsj.2015.41770}, abstract = {Chehrabad Cu deposit is located in the Zanjan province and in the northwest corner of Central Iran. Rock units exposed in this area belong to the Cenozoic era (especially Miocene period) and include the Lower Red Formation, Qom Formation, Upper Red Formation and Quaternary deposits. In the study area, the Upper Red Formation which hosts the mineralization consists of alternating beds of marl, siltstone, oxidized red sandstone and light gray sandstone. Mineralization has occurred within the gray sandstones of bleached zone containing organic materials. In Chehrabad, copper deposit mineralization has been recognized in five horizons. Each horizon is composed of three zones including reduced zone with mineralization, bleached zone and oxidized red zone. The dominant texture in the Chehrabad Cu deposit is replacement texture which is accompanied with other textures such as disseminated, solution seams, lens like and interparticle cement texture. Lithology (sandstone host rock), sulfide mineralogy (e.g. pyrite, chalcocite, bornite and chalcopyrite), structure and texture, stratigraphy as well as factors controlling the mineralization (presence of plant remains performing as environment reductant and also the permeability in the host rock) suggest that this deposit is similar to the red-bed type sedimentary Cu deposits which is formed during the early to late diagenesis. Chehrabad Cu deposit is located in the Zanjan province and in the northwest corner of Central Iran. Rock units exposed in this area belong to the Cenozoic era (especially Miocene period) and include the Lower Red Formation, Qom Formation, Upper Red Formation and Quaternary deposits. In the study area, the Upper Red Formation which hosts the mineralization consists of alternating beds of marl, siltstone, oxidized red sandstone and light gray sandstone. Mineralization has occurred within the gray sandstones of bleached zone containing organic materials. In Chehrabad, copper deposit mineralization has been recognized in five horizons. Each horizon is composed of three zones including reduced zone with mineralization, bleached zone and oxidized red zone. The dominant texture in the Chehrabad Cu deposit is replacement texture which is accompanied with other textures such as disseminated, solution seams, lens like and interparticle cement texture. Lithology (sandstone host rock), sulfide mineralogy (e.g. pyrite, chalcocite, bornite and chalcopyrite), structure and texture, stratigraphy as well as factors controlling the mineralization (presence of plant remains performing as environment reductant and also the permeability in the host rock) suggest that this deposit is similar to the red-bed type sedimentary Cu deposits which is formed during the early to late diagenesis.}, keywords = {Upper Red formation,Structure and Texture,Red Bed type sedimentary Cu deposits,Chehrabad,Zanjan}, title_fa = {کانه‌زایی، کانی‌شناسی، ساخت و بافت کانسار مس رسوبی چهرآباد، شمال‌باختر زنجان}, abstract_fa = {کانسار مس چهرآباد در استان زنجان و در گوشه شمال‌ باختری پهنه ایران مرکزی واقع شده است. واحدهای سنگی موجود در این منطقه متعلق به سنوزوییک (بیشتر میوسن) بوده که شامل سازند سرخ زیرین، سازند قم، سازند سرخ بالایی و نهشته‌های کواترنری هستند. در منطقه مورد مطالعه، سازند سرخ بالایی که میزبان کانه‌زایی به‌شمار می‌رود، شامل تناوبی از مارن، سیلت‌سنگ، ماسه‌سنگ‌‌‌ اکسیدان سرخ و ماسه‌سنگ‌ خاکستری روشن است. کانه‌زایی مس در بخش‌های دارای مواد آلی درون ماسه‌سنگ‌های خاکستری پهنه شسته‌ شده رخ داده است. در کانسار مس چهرآباد 5 افق کانه‌زایی شناسایی شد و هر یک از این افق‌ها شامل سه پهنه کانه‌زایی شده، شسته‌ شده و سرخ اکسیدان است. بافت چیره در رخداد کانه‌زایی، بافت جانشینی است و بافت‌های دیگری مانند دانه‌پراکنده، شبه‌لامینه‌ای، عدسی‌شکل و سیمان میان‌دانه‌ای نیز دیده می‌شوند. این کانسار از دید سنگ‌شناسی (سنگ میزبان ماسه‌سنگی)، کانی‌شناسی سولفیدی (از جمله پیریت، کالکوسیت اولیه، بورنیت، کالکوپیریت و آرژنتیت)، ساخت و بافت، چینه‌شناسی و عوامل کنترل کننده کانه‌زایی (وجود آثار و بقایای گیاهی به عنوان عامل اصلی احیا کننده محیط و همچنین وجود نفوذپذیری مناسب در سنگ میزبان) همانند کانسارهای مس رسوبی نوع Red Bed است که طی دیاژنز اولیه تا نهایی تشکیل شده است.}, keywords_fa = {سازند سرخ بالایی,ساخت و بافت,مس رسوبی نوع Red Bed,چهرآباد,زنجان}, url = {http://www.gsjournal.ir/article_41770.html}, eprint = {http://www.gsjournal.ir/article_41770_0ecccd2067243fd3438ce244ec3e424a.pdf} }