Journal of Economic Geology最新文献

{"title":"سنگ شناسی، سن سنجی، ژئوشیمی و تعیین منشأ توده های گرانیتوئیدی منطقه بجستان، شمال فردوس، استان خراسان رضوی","authors":"ریحانه احمدی روحانی, محمدحسن کریم پور, بهنام مغانی رحیمی, آزاده ملکزاده شفارودی, اورس کلوتزلی, ژوزه فرانسیسکو سانتوس","doi":"10.22067/ECONG.V8I2.57139","DOIUrl":"https://doi.org/10.22067/ECONG.V8I2.57139","url":null,"abstract":"Introduction \u0000The investigated area is situated in the south west of the Khorasan Razavi Province along the North West of the Lut Block. Different types of metal ore bodies along with non-metal deposits have already been documented in the Lut Block (Karimpour et al., 2008). Most of the study area is covered with granitoid rocks. Metamorphic rocks with unknown age are present in the north of the area. Skarns are observed in contact with fault zones and intrusive bodies. Eocene volcanic rocks with andesite and andesibasalt composition are located in the east and north east of the area (Ahmadirouhani et al., 2015). The study area that is a part of the Lut Block has a high potentials for Cu, Fe, Au, and Barite mineralization along the observed alteration zones. In the present study, the petrography, petrogenesis, Sr–Nd isotopes, and U–Pb zircon age of acidic granitoids in the east of Bajestan were investigated. \u0000 \u0000Materials and methods \u0000In the current study, 400 rock samples were collected from the field and 170 thin sections were prepared for petrography studies. Thirty samples of volcanic rocks, intrusions, and dykes were analyzed using XRF at the Geological Survey of Iran. Twenty-five samples were selected for the elemental analysis using ICP-MS by the Acme Lab Company (Canada), 16 samples of them were related to acidic intrusive bodies and dykes. In addition, zircon crystals from four samples of the granitoids bodies were collected for U–Pb dating. Approximately 50 zircon grains (i.e. euhedral, clear, uncracked crystals with no visible heritage cores and no inclusions) were hand-picked from each sample. Through cathodoluminescence imaging, the internal structure and the origin of zircon grains were examined at the Geological Survey of Vienna, Austria. Moreover, zircons were dated using the (LA)-ICP-MS method at the Laboratory of Geochronology, the University of Vienna, Austria using the methodology outlined in Klotzli et al., (2009). Sr and Nd isotopic compositions were also determined for the same samples (i.e. U-Pb samples) using the whole-rock method. The samples were analyzed in the Laboratorio de Geologia Isotopica da Universidade de Aveiro, Portugal. \u0000 \u0000Results \u0000Granitoids in the study area have mostly monzogranite (biotite monzogranite, hornblende biotite monzogranite and pyroxene hornblende biotite monzogranite), granite, and syenogranite composition. Granular, micro-granular, and porphyritic textures are common textures in these rocks. Common mafic minerals in these rocks include biotite, hornblende and pyroxene. Based on mineralogy, low values of magnetic susceptibility, high aluminum saturation index, and high initial 87Sr/86Sr ratios (> 0.710) of the study of granitoid rocks belong to the ilmenite-series of the reduced S-type granitoids. These magmas originated from the upper continental crust at a syncollosion zone. Furthermore, the rocks normalizing spider diagrams showed characteristics of a crustal environment. The age of the gran","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"8 1","pages":"525-552"},"PeriodicalIF":0.0,"publicationDate":"2017-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45796478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"زمین شناسی، دگرسانی، کانه زایی، ژئوشیمی اکتشافی و پترولوژی توده های نفوذی در محدوده اکتشافی شاه سلطان علی (جنوب غربی بیرجند، استان خراسان جنوبی)","authors":"سمانه نادرمزرجی, محمدحسن کریم پور, آزاده ملکزاده شفارودی","doi":"10.22067/ECONG.V9I1.61010","DOIUrl":"https://doi.org/10.22067/ECONG.V9I1.61010","url":null,"abstract":"منطقه اکتشافی شاه سلطان‌علی در شرق بلوک لوت و جنوب غربی بیرجند قرار دارد. در این منطقه طیف گسترده ای از واحدهای نیمه‌عمیق با ترکیب مونزونیت پورفیری، مونزودیوریت- پورفیری و دیوریت پورفیری درون واحدهای آتشفشانی با ترکیب آندزیت‌– بازالت نفوذ کرده، و به تشکیل انواع دگرسانی‌های پروپلیتیک، کوارتز‌– سرسیت‌– پیریت، آرژیلیک، سیلیسی، سرسیتی و کربناته منجر شده است. طبق بررسی‌های ژئوشیمیایی، تودههای درونی منطقه همه از نوع متا‌ آلومینوس با ماهیت کالک‌آلکالن پتاسیم بالا تا شوشونیتی است و این توده‌‌ها در دسته مگنتیت نوع I طبقه‌بندی می شوند. غنی شدگی عناصر LREE نسبت به HREE همراه با آنومالی منفی Nb نشان دهنده تشکیل ماگما در زون فرورانش است. از نظر تکتنوماگمایی توده های بالا در محیط گرانیتوئیدهای کمان‌های آتشفشانی قرار می گیرند. کانی سازی اصلی منطقه در واحد‌های مونزونیت پورفیری و مونزودیوریت پورفیری با دگرسانی کوارتز‌– سرسیت‌– پیریت رخ‌داده است. این توده ها بالاترین تراکم رگه‌چه، بالاترین درصد اکسید آهن و بیشترین ناهنجاری ژئوشیمیایی عناصر را نشان می دهند. همچنین چهار نوع کانی‌سازی استوک ورک، رگه ای، افشان و برش گرمابی همراه این توده‌ها دیده می‌شود. در بررسی‌های ژئوشیمیایی خرده‌سنگی، دامنه تغییرات عناصری مثل مس از 30 تا 454 گرم در تن، روی 27 تا 279 گرم در تن، آنتیموان 9/0 تا 152 گرم در تن، طلا 5 تا 128 میلی گرم در تن متغیر است که این آنومالی ها بر دگرسانی کوارتز‌– سرسیت‌– پیریت با کانی سازی استوک ورک منطبق است. با توجه به تنوع واحد‌های نیمه‌عمیق نوع I با ماهیت کالک‌آلکالن پتاسیم بالا تا شوشونیتی، گسترش و نوع آلتراسیون ها، کانی سازی استوک ورک و آنومالی عناصر، احتمالا این منطقه مرتبط با سیستم های مس پورفیری است.","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"9 1","pages":"117-139"},"PeriodicalIF":0.0,"publicationDate":"2016-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"مطالعات کانی سازی، ژئوشیمی، سیالات درگیر و ایزوتوپ پایدار گوگرد کانسار Cu-Zn-As باقرق با سنگ میزبان کربناته (شمال شرق انارک)","authors":"محمد علی جزی, محمدحسن کریم پور, آزاده ملکزاده شفارودی","doi":"10.22067/econg.v7i2.46069","DOIUrl":"https://doi.org/10.22067/econg.v7i2.46069","url":null,"abstract":"Introduction \u0000The Baqoroq Cu-Zn-As deposit is located northeast of the town ofAnarak in Isfahan province, in theeast central areaof Iran. Copper mineralization occursin upper cretaceous carbonate rocks.Studyof thegeologyof the Nakhlak area, the location ofa carbonate-hosted base metaldeposit, indicatesthe importance of stratigraphic, lithological and structural controls in the placement of this ore deposit. (Jazi et al., 2015).Some of the most world’s most important epigenetic, stratabound and discordant copperdeposits are the carbonate hosted Tsumeb and Kipushi type deposits,located in Africa. The Baqoroq deposit is believed to be of this type. \u0000 \u0000Materials and methods \u0000In the current study, fifty rock samples were collected from old tunnels and surface mineralization. Twenty-two thin sections, ten polished sections and four thin-polished sections were prepared for microscopic study. Ten samples were selected for elemental analysis by ICP-OES (Inductively coupled plasma optical emission spectrometry) by the Zar Azma Company (Tehran) and AAS (Atomic absorption spectrometry) at the Ferdowsi University of Mashhad. Seven doubly polished sections of barite mineralization were prepared for microthermometric analysis. Homogenization and last ice-melting temperatures were measured using a Linkam THMSG 600 combined heating and freezing stage at Ferdowsi University of Mashhad. Sulfur isotopes of five barite samples were determined by the Iso-Analytical Ltd. Company of the UK. The isotopic ratios are presented in per mil (‰)notation relative to the Canyon Diablo Troilite. \u0000 \u0000Results \u0000The upper Cretaceoushost rocks of the Baqoroq deposit include limestone, sandstone, and conglomerate units. Mineralization is controlled by two main factors: lithostratigraphy and structure. Epigenetic Cu-Zn mineralizationoccurs in ore zones as stratabound barite and barite-calcite veins and minor disseminated mineralization. Open space filling occurred as breccia matrix, crustification banding,andbotryoidaltexture. The host rock has undergone dolomitization alteration \u0000Hypogene minerals include chalcopyrite, pyrite, sphalerite, galena, enargite, barite, and calcite. Supergene minerals include malachite, azurite, covellite, chrysocolla, chalcocite, cerussite, smithsonite, native copper and iron oxide minerals. Sulfantimonides and sulfardenides are abundant in low- and moderate temperature stages of the deposit, while bismuth sulfides generally occur in higher temperature ores, according to Malakhov, 1968. \u0000Analysis of rich ore samples indicates copper is the most abundant heavy metal in the ore (average 20.28 wt%), followed by zinc (average ~ 1 wt%) and arsenic (average ~ 1 wt%), respectively. Thepresence of many trace elements in the ore, such as Sb, Pb, Ag and V, are very important. Element pairs such as Ag-Cu, Zn-Cd, Zn-Sb, Fe-V and Pb-Mo are correlated with each other. The Baqoroq ore minerals are rich in As, Sb and poor in Bi. Highamountsof antimony usually occur in a low","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"7 1","pages":"179-202"},"PeriodicalIF":0.0,"publicationDate":"2016-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"زمین شناسی، کانی سازی، سن سنجی U-Pb و ژئوشیمی ایزوتوپ های Sr-Nd توده های نفوذی شمال شرق کاشمر","authors":"علی الماسی, محمدحسن کریم پور, خسرو ابراهیمی نصرآبادی, بهنام مغانی رحیمی, اورس کلوتزلی, ژوزه فرانسیسکو سانتوس","doi":"10.22067/ECONG.V7I1.44721","DOIUrl":"https://doi.org/10.22067/ECONG.V7I1.44721","url":null,"abstract":"محدوده مطالعاتی در 30 کیلومتری شمال شرق کاشمر قرار دارد. براساس سن سنجی زیرکن توده های نفوذی نوع I (سن 40 میلیون سال)، در زمان ائوسن و در پاسخ به فشارش ناحیه ای، حرکات امتدادلغز چپ‌گرد گسلهای درونه و تکنار سبب رخداد زون برشی، حوضه pull-apart و شکستگیهای ریدل شده که شرایط را برای صعود ماگما و محلول گرمابی مهیا کرده است. طی تکامل ساختاری منطقه، چند ضربان ماگمایی کالکوآلکالن تا آلکالن پتاسیم بالا تا شوشونیتی نوع I و یک پالس نوع A در منطقه نفوذ کرده است. مقادیر اولیه 87Sr/86Sr (706/0-705/0) و 143Nd/144Nd (5126/0-5125/0) برای سری I، منشأ پوسته قاره ای با دخالت گوشته (فرورانش) را نشان می دهد. ماگمای عامل دسته دایک های کوارتزمونزونیتی جدید نوع I، سبب دگرسانیها و کانی سازی IOCG در منطقه شده است. دو مرحله چرخش محلول گرمابی اکسیدان آهن دار سبب دگرسانیهای آرژیلیک پیشرفته، سرسیتی، سیلیسی، اکسیدآهن، کربناتی، اپیدوتی و کلریتی و کانی سازی رگه ای سولفید فلزات پایه و رگه های IOCG غنی از اسپکیولاریت در منطقه شده است.","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"7 1","pages":"69-90"},"PeriodicalIF":0.0,"publicationDate":"2015-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"پترولوژی و ژئوشیمی هورنبلند گابروهای پروتروزوئیک جنوب شرق فریمان، استان خراسان رضوی","authors":"سیدمسعود همام","doi":"10.22067/ECONG.V7I1.33610","DOIUrl":"https://doi.org/10.22067/ECONG.V7I1.33610","url":null,"abstract":"Introduction \u0000Hornblende-bearing gabbroic rocks are quite common in subduction-related magmatic suites and considered to represent magmatic differentiation process in arc magmas (Heliker, 1995; Hickey-Vargas et al., 1995; Mandal and Ray, 2012). The presence of hornblende as an important mineral phase in gabbroic rocks of subduction zone has been considered either as an early crystallizing mineral from water-bearing mafic magmas (Beard and Borgia 1989; Mandal and Ray, 2012) or as a product of reaction of early crystallized minerals (olivine, pyroxene and plagioclase) and water-rich evolved melt/aqueous fluid (Costa et al., 2002; Mandal and Ray, 2012). The careful study of petrology and geochemistry of hornblende-bearing gabbroic rocks from Chahak area, of Neoproterozoic age, can provide important information about their petrogenesis. Because of the special characteristics of Chahak hornblende gabbros according to their age and their situation in the main structural units of Iran, their study can present critical keys for the knowledge of geological history of Iran specially central Iran zone. \u0000 \u0000Material and Methods \u0000This study carried out in two parts including field and laboratory works. Sampling and structural studies were carried out during field work. Geological map for the study area was also prepared. 65 thin and polished thin sections for petrographical purpose were studied. Major oxides, rare earth elements and trace elements were analyzed for 4 samples (92P-1, 92P-3, B1and B6) from hornblende gabbros on the basis of 4AB1 method using ICP-MS of ACME Laboratory from Canada. In addition, major oxides of three hornblende gabbro samples (89P-62, 89P-59 and 89P-46) were used from Partovifar (Partovifar, 2012). \u0000 \u0000Results and discussion \u0000Fariman metamorphic terrains, of Proterozoic age, consist of metamorphosed sedimentary and igneous (plutonic and volcanic) rocks. Hornblende gabbros of the study area include plagioclase, hornblende, biotite pyroxene and olivine as major minerals and apatite, ilmenite and magnetite as minor minerals. In many examples, hornblende and biotite can be seen as corona textures around plagioclase, pyroxene and olivine, while plagioclase, pyroxene and olivine show obviously corrosion features. This can be considered to be formed by the reaction of early formed crystals with aqueous fluid/evolved melt. In some cases, amphiboles show rhythmic overgrowths. The rhythmic amphibole overgrowths represent deep-seated crystallization in a volatile-rich magma under conditions of high but varying gas pressure. In the study area, the most dominant texture of the hornblende gabbros is hypidiomorphic granular, but intergranular and porphyric textures are common too. \u0000Based on geochemical data from major and minor elements, studied rocks belong to tholeiite series with meta–aluminous nature. The geochemical behavior of main elements of the studied rocks reveals the normal trend of differentiation in their magma. Chondrite-normalized ","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"7 1","pages":"91-109"},"PeriodicalIF":0.0,"publicationDate":"2015-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenesis and zircon U-Pb dating of skarnified pyroxene-bearing dioritic rocks in Bisheh area, south of Birjand, eastern Iran","authors":"ملیحه نخعی, سیداحمد مظاهری, محمدحسن کریم پور, جی لنگ فارمر, چارلز استرن, محمد حسین زرین کوب, محمدرضا حیدریان شهری","doi":"10.22067/ECONG.V6I2.31772","DOIUrl":"https://doi.org/10.22067/ECONG.V6I2.31772","url":null,"abstract":"Introduction \u0000The study area is located 196 km south of Birjand in eastern border of the Lut block )Berberian and King, 1981) in eastern Iran between 59°05′35\" and 59°09′12\" E longitude and 31°42′29\" and 31°44′13\" N latitude. The magmatic activity in the Lut block began in the middle Jurassic such as Kalateh Ahani, Shah Kuh and Surkh Kuh granitoids that are among the oldest rocks exposed within the Lut block (Esmaeily et al., 2005; Tarkian et al., 1983; Moradi Noghondar et al., 2011-2012). Eastern Iran, and particularly the Lut block, has great potential for different types of mineralization as skarnification in Bisheh area which has been studied in this paper. The goal of this study is to highlight the geochronology, geochemistry of major and trace elements, Rb-Sr, Sm-Nd isotopes for skarnified pyroxene-bearing diorites. \u0000 \u0000Materials and methods \u0000Major element compositions of thirteen samples were determined by wavelength-dispersive X-ray fluorescence (XRF) spectrometry, using fused discs and the Phillips PW 1410 XRF spectrometer at Ferdowsi University, Mashhad, Iran. These samples were analysed for trace elements using inductively coupled plasma-mass spectrometry (ICP-MS) in the Acme Analytical Laboratories, Vancouver, British Columbia, Canada. \u0000Zircon grains were separated from pyroxene diorite porphyrys using heavy liquid and magnetic techniques at the Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan. Zircon U-Pb dating was performed by laser ablation-inductively-coupled plasma-mass spectrometry (LA-ICP-MS), using an Agilent 7500 s machine and a New Wave UP213 laser ablation system, equipped at the Dr Shen-Su Sun memorial laboratory in the Department of Geosciences, National Taiwan University, Taiwan. \u0000Strontium and Nd isotopic analyses were performed on a six-collector Finnigan MAT 261 thermal-ionization mass spectrometer at the University of Colorado, Boulder, Colorado, United States. 87Sr/86Sr ratios were determined using four-collector static mode measurements. Several measurements of SRM-987 during the study period yielded a mean of 87Sr/86Sr = 0.71032 ± 2 (error is the 2σ mean). Measured 87Sr/86Sr ratios were corrected to SRM-987 = 0.71028. Measured 143Nd/144Nd was normalized to 146Nd/144Nd = 0.7219. Analyses were conducted as dynamic mode, three-collector measurements. Several measurements of the La Jolla Nd standard during the study period yielded a mean of 143Nd/144Nd = 0.511838 ± 8 (error is the 2σ mean). \u0000 \u0000Results \u0000In the Bisheh area that is located east of Lut block, pyroxene-bearing dioritic rocks are high-K calk-alkaline and meta-aluminous. Primitive mantle-normalized trace element spider diagrams display strong enrichment in LILE, such as Rb, Ba, and Cs, and depletion in some HFSE, e.g., Nb, P, Ti, Y and Yb. Chondrite-normalized REE diagrams show (La/Yb)N ratios ranging from 7.75 to 8.63 and small negative Eu anomalies. These features along with high Th/Yb and Ta/Yb ratios show that magmatism is related to continen","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"6 1","pages":"393-409"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"کانی شناسی، زمین شیمی، منشأ و مصرف صنعتی سیلیس منطقه عارفی، جنوب مشهد","authors":"محمدحسن کریم پور, آزاده ملکزاده شفارودی, سعید سعادت","doi":"10.22067/econg.v6i2.34264","DOIUrl":"https://doi.org/10.22067/econg.v6i2.34264","url":null,"abstract":"کنگلومرای کوارتزدار عارفی (با سن ژوارسیک میانی) در زون ساختاری بینالود واقع شده است. این واحد دارای روند شمال غربی- جنوب شرقی است و در 25 کیلومتری جنوب مشهد رخنمون دارد. بیش از 97 درصد کنگلومرا از انواع مختلف کوارتز در قالب کوارتزهای مونوکریستالین، پلی‌کریستالین و به مقدار خیلی کمتر خرده‌سنگ از نوع چرت، کوارتزیت و یا میکا ‌شیست تشکیل‌شده است. کمتر از 3 درصد دیگر شامل فلدسپات، میکا، کلریت، هورنبلند، تورمالین، زیرکن، اسفن و کانی اوپاک است. سیمان از نوع سیلیسی است. \u0000مطالعه سیالات درگیر در کوارتزهای مونوکریستالین و پلی کریستالین نشان‌دهنده حضور سیالات سه فازی LVS حاوی نمک طعام است. دمای همگن شدن آنها بین 484 تا بیش از 600 درجه سانتی‌گراد با میانگین دمای 559 درجه سانتی‌گراد و شوری بین 6/49 تا 1/72 درصد NaCl با میانگین 2/61 درصد می باشد که مؤید ماهیت ماگمایی آنهاست. دامنه دمای همگن شدن در سیالات درگیر دوفازی LV در کوارتز دگرگونی بین 287 تا 365 درجه سانتی‌گراد با میانگین دمای 318 درجه سانتی‌گراد است. مهمترین منشأ کوارتزهای موجود در کنگلومرا، رگه های کوارتز در بخش فوقانی توده های گرانیتی – پگماتیتی (تریاس فوقانی) محدوده خواجه مراد و رگه های کوارتز تشکیل شده در زمان دگرگونی ناحیه ای است. \u0000برپایه تجزیه ژئوشیمیایی 93 نمونه برداشت شده از سطح (روش کانالی) و حفاری پودری از عمق، مقدار SiO2 عمدتا بیش از 98 درصد، مقدار TFeO کمتر از 42/0 درصد و TiO2 کمتر از 16/0 درصد است. میزان ذخیره قطعی بیش از 50 میلیون تن است. با انجام آزمایشهای مغناطیسی خشک مقدار TFeO به 03/0 درصد و TiO2 به 02/0 درصد نیز کاهش یافته است. ذخیره سیلیس عارفی از نوع سیلیس درجه یک محسوب شده و برای انواع مختلف صنایع سرامیک می تواند استفاده شود.","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"81 1","pages":"259-276"},"PeriodicalIF":0.0,"publicationDate":"2015-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"زمین شناسی، کانی شناسی و ژئوشیمی آنومالی فرومنگنز فرزنه، شرق مجموعه معدنی سنگان خواف","authors":"نازی مظهری, آزاده ملکزاده شفارودی, مجید قادری","doi":"10.22067/ECONG.V7I1.44694","DOIUrl":"https://doi.org/10.22067/ECONG.V7I1.44694","url":null,"abstract":"محدوده اکتشافی فرزنه از آنومالی‌های منتهاالیه شرقی مجموعه معدنی سنگان خواف است، که در جنوب‌شرق مشهد قرار دارد. زمین‌شناسی این منطقه شامل شیل‌، ماسه‌سنگ‌ و واحدهای کربناته به سن ژوراسیک و توده‌های نفوذی ترشیری با ترکیب گرانیتی است. ورود سیالات گرمابی موجب تبلور دوباره سنگهای کربناتی و دگرسانی پروپیلیتیک در آنها و کانه‌زایی آهن و منگنز به شکل توده‌ای، استراتاباند و به‌صورت دیرزاد شده‌ است که رخداد کانی‌سازی از الگوی تکتونیک منطقه پیروی می‌کند. \u0000کانی‌سازی در منطقه اکتشافی فرزنه محدود به اکسید‌های آهن و منگنز شامل گوتیت، هماتیت، پیرولوسیت، پسیلوملان و به میزان کمتر کریپتوملان است. انجام آنالیز پراش پرتو ایکس (XRD) نیز کانی‌زایی فرومنگنز و رخداد اکسیدهای آهن و منگنز را تأیید می‌کند. نتایج آنالیزهای ژئوشیمی (XRF و ICP-MS) نشان می‌دهد که تغییرات آهن از 5/43 تا 68 درصد، منگنز از 9/1 تا 8/4 درصد، مس از 20 تا 1063 گرم در تن و دامنه تغییرات برای آرسنیک از 20 تا 1269 پی‌پی‌ام است. نسبت Fe/Mn در نمونه‌های این منطقه از 15 تا 25 و نسبت LREE/HREE از 58/2 تا 78/13 در تغییر می‌باشد. غنی‌شدگی ملایمی از LREE و آنومالی مثبت Eu در داده‌های ژئوشیمی مشاهده می‌شود. براساس مقادیر اکسید‌های اصلی Fe، Mn و Siو همچنین عناصر فرعیCu ،Ni ، Co، Zn، Pb،، Mo، V، As کانی‌سازی محدوده اکتشافی فرزنه دارای منشأ گرمابی است. مدل کانی‌سازی و رخداد آنومالی فرومنگنز فرزنه، هیچ ارتباط و شباهتی با کانی‌زایی اسکارن آهن در بخش اصلی مجموعه معادن سنگان ندارد و این آنومالی مرتبط با فعالیت سیالات گرمابی (کانی‌سازی سولفیدی شسته شده) که احتمالا جوانتر از کانی‌سازی اسکارن در منطقه هستند و از طریق زون‌ گسلی به اعماق کمتر و سطح زمین راه پیدا کرده‌اند، می باشد.","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"7 1","pages":"23-37"},"PeriodicalIF":0.0,"publicationDate":"2014-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GEOLOGY, ALTERATION, AGE DATING AND PETROGENESIS OF INTRUSIVE BODIES IN HALAK ABAD PROSPECT AREA, NE IRAN","authors":"Ghourchi Maliheh, K. M. Hassan, J. Farmer, S. Charles","doi":"10.22067/ECONG.V6I1.23015","DOIUrl":"https://doi.org/10.22067/ECONG.V6I1.23015","url":null,"abstract":"The Halak Abad prospect occurs in the northeastern part of Central Iran zone (Sabzevar structural zone). In this investigation, geochemical evolution, age and source of part of northeastern Iran magmatic arc (intrusive bodies) in Halak Abad area in the Khorasan Razavi province has been studied. The exposed rocks consist of volcanic rocks with andesite and dacite nature, limestone, plutonic rocks mostly diorite, quartz diorite, monzodiorite, quartz monzonite, granodiorite and granite and sedimentary rocks such as limestone, sandstone and conglomerate. Magnetic susceptibility of intrusive rocks is >100 × 10-5 SI, so they belong to the magnetite-series (oxidized). This magmatism is mainly low-K (tholeiite series) and meta-aluminous. The amounts of Zr, Th, Nb and Ti show depletion compared to N-MORB. Trace elements behavior shows a nearly flat pattern. Age of granodiorite body based on U-Pb zircon dating is 99.7±1.8 Ma (Mid-Cretaceous) and 87Sr/86Sr initial ratio is 0.7047. The geochemical signature and 87Sr/86Sr initial ratio in the area suggest volcanic arc magmatism in subduction zone. This magmatism has characteristic such as high Na2O (3-7 %), low K2O (0.12-1 %), high CaO (4-5.7%), low Rb (1-20 ppm), low total REE (&lt40 ppm), high Ba/Nb, Sm/Yb&lt2, (La/Yb)N&lt5, 87Sr/86Sr initial ratio < 0.7045 and eNd: +4.5 show differences with normal granitoids in subduction zones. Geochemical and petrological characteristics indicate melting in relatively low pressure (shallow depth). The lines of evidence demonstrate that formation of this granitoid needs a suprasubduction zone.","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"6 1","pages":"23-48"},"PeriodicalIF":0.0,"publicationDate":"2014-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GEOLOGY, MINERALIZATION, RB-SR & SM-ND GEOCHEMISTRY, AND U–PB ZIRCON GEOCHRONOLOGY OF KALATEH AHANI CRETACEOUS INTRUSIVE ROCKS, SOUTHEAST GONABAD","authors":"K. M. Hassan, Malekzadeh Shafaroudi Azadeh, Moradi Neghondar Mehrab, S. Charles, Farmer J. Lang","doi":"10.22067/ECONG.V5I2.31806","DOIUrl":"https://doi.org/10.22067/ECONG.V5I2.31806","url":null,"abstract":"Kalateh Ahani is located 27 km southeast of Gonabad within the Khorasan Razavi province. The area is part of Lut Block. Sub-volcanic monzonitic rocks intruded regional metamorphosed Shemshak Formation (Jurassic age). Magnetic susceptibility of less altered monzonitic rocks is 0.6%., As, Pb and Zn > 1%, Au up to 150 ppb and Sn = 133 ppm. The Sn content of vein in the northern part of Kalateh Ahani (Rud Gaz) is > 1%. \u0000Based on mineralization, alteration and geochemistry, it seems that Sn mineralization is associated with the Cretaceous monzonitic rocks. Zircon U–Pb dating indicates that the age of the monzonitic rocks associated with mineralization is 109 Ma (Lower Cretaceous). Based on (87Sr/86Sr)i = 0.71089-0.710647 and (143Nd/144Nd)i = 0.512113-0.51227 of the monzonitic rocks, the magma for these rocks were originated from the continental crust. This research has opened new window with respect to Sn-Cu mineralization and exploration within the Lut Block which is associated with Cretaceous granitoid rocks (reduced type, ilmenite series) originated from the continental crust.","PeriodicalId":37178,"journal":{"name":"Journal of Economic Geology","volume":"20 1","pages":"267-290"},"PeriodicalIF":0.0,"publicationDate":"2013-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68565241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}