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Fluid Inclusion Investigations of the Masjed Daghi Copper-Gold Porphyry-epithermal Mineralization, East Azerbaijan Province, NW Iran

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Open Journal of Geology 2017年第8期7卷 1110-1127页

作者： Solat Atalou Nima Nazafati Mohammad Lotfi Mehraj Aghazadeh Department of Geology Science and Research Branch Islamic Azad University Tehran Iran Department of Geology North Tehran Branch Islamic Azad University Tehran Iran Department of Geology Payame Nour University Tehran Iran

The Masjed Daghi mineralization is located 30 km southeast of Jolfa city at the bank of Araxes River, northwest Iran. This area is situated in the Alborz-Azarbaijan structural zone of Iran. The most widespread rocks in the mineralization area are andesite and trachyandesite, while there are rock units of latite tuff, andesitic agglomerate, and hornblende porphyry basalt in eastern hills and Eocene flysch in the southern part of the area. Several intrusive bodies are present in the study area, from which the dominant intrusive rock hosting the mineralization is diorite porphyry. The mineralized rock units of the area are cut by different diorite ad mafic dikes. The most prevalent texture of mineralization is dissemination, while open space filling textures including veins and veinlets, are common as well. Diverse types of alteration including potassic, phyllic, argillic, silicification, and a little of carbonatization were recognized in the field and microscopic observations as well as by XRD. In addition to thick silica veins and stockwork zones, some silica, barite, sulfide, and calcite veins and veinlets have occurred in the Masjed Daghi mineralization area. In this research, 26 doubly polished thin sections (wafers) were prepared and investigated. Four samples were taken from surface veins, while 22 samples were chosen from core samples (of 6 boreholes) of white and grey-white silica, and silica-barite veins. The fluid inclusion studies on 105 primary fluid inclusions indicated five phases for inclusions including: 1) liquid or gas, 2) liquid and gas, 3) liquid, gas, and solid, 4) liquid, gas, halite, and solid, and 5) liquid, gas, halite, and two types of solids. The data gained from fluid inclusions approved two mineralization fluids which caused porphyry and epithermal mineralizations. The porphyry fluid inclusions were homogenized in temperatures of 122°C to 550°C with a maximum of 700°C and average salinity of 55 wt% NaCl equivalent, while the epithermal inc

关键词： Fluid Inclusion Porphyry Mineralization epithermal Alteration Diorite Masjed Daghi Siyah Roud

The fluid regime of formation of epithermal ore mineralization in the eastern part of the Aldansky shield (Russian Far East)

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Chinese Science Bulletin 1999年第S2期44卷 235-236页

作者： V. E. Kirillov N. V. Berdnikov Far Eastern Geological Institute FEB RAS Ave 100 let. Vlad. 159 Vladivostok 690022 Russia Institute of Tectonics and Geophysics RAS 65 Kim-Yu-Chen Khabarovsk 680000 Russia

IN the eastern part of the Aldansky shield, on the territory of volcanic and sedimentary basins of Proterozoic age, many deposits and ore occurrences of Au, Ag, Mo, U, V, Ni, Co, Ba and Th are ***, geochemical and fluid inclusion study indicate their low temperature (epithermal) *** is supposed that these ores were formed in the grenville metallogenic epoch (Upper Proterozoic). The epithermal ores in this region are connected with: (i) eisite (apatite-albite metasomatites)and (ii) argilliceous-white mica metasomatites (argillisites and beresites). Apatite-albite metasomatitesare associated with rare-earth ores. As a rule, metasomatite bodies are controlled by steeply-dipping fractures. Albite, quartz and fine-grained hematite form a typical mineral assiciation. The ore bearing metasomatites were formed at pH = 4 and T≤300℃. The beresite type argillaceous-white mica alterations are widespread in volcanic rocks of the Ulkansky basin and in the sedimentary suites of the Uchursky basin. They are distinguished on all stratigraphiclevels, but especially often in a zone of structural-stratigraphic unconformity (SSU) of AR-PR. Au, Ag,Mo, V and U deposits and occurrences are connected with this type of alterations. Their structural pos-

关键词： fluid regime epithermal ore mineralization Aldansky shield.

Laumontitization as an Exploration Indicator of epithermal Gold Deposits: A Case Study of the Axi and Other epithermal Systems in West Tianshan, China

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Chinese Journal Of Geochemistry 2003年第4期22卷 289-301页

作者：陈衍鲍景新张增杰陈华勇刘玉琳 Departmemt of Geology Peking University Guiyang Institute of Geochemistry Chinese Academy of Sciences

In the light of field investigation, microscopic study, X\|ray phase analysis and mineral infrared spectral analysis, it is considered that laumontitization is of extensive occurrence in the Axi gold orefield. The development of laumontitization and its relationship to mineralization show that the laumontitization appeared mainly at the top of and in the periphery of orebodies, and occurred at the edge of the epithermal system or at the late stage of epithermal system evolution. Therefore, laumontitization can be used as an exploration indicator of epithermal gold deposits. The fluids responsible for laumontitization in the Axi gold orefield are similar to those producing hot spring\|type gold deposits or those from modern geothermal fields. epithermal mineralization of the Axi gold deposit was dated at Carboniferous, indicating that the West Tianshan of China is a region favorable to epithermal\|type gold mineralization and preservation. Hence the West Tianshan of China is a target area for exploring epithermal gold deposits.

关键词： Axi gold deposit laumonfitizafion epithermal gold deposit geothermal metaliogenic system West Tianshan

Petrogenesis of Quebrada de la Mina and Altar North porphyries (Cordillera of San Juan, Argentina): Crustal assimilation and metallogenic implications

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Geoscience Frontiers 2017年第5期8卷 1135-1159页

作者： Laura Maydagán Marta Franchini Massimo Chiaradia Verónica Bouhier Noelia Di Giuseppe Roger Rey Luis Dimieri Centro Patagónico de Estudios Metalogenéticos-CONICET Argentina INGEOSUR-CONICET Departamento de Geología Universidad Nacional del Sur San Juan 670 8000 Bahía Blanca Argentina Instituto de Investigación en Paleobiología y Geología Universidad Nacional de Río Negro Av. Roca 1242 8332 Roca Argentina Departamento de Geología y Petróleo Facultad de Ingeniería Universidad Nacional del Comahue Buenos Aires 1400 8300 Neuquén Argentina Section of Earth and Environmental Sciences University of Geneva Switzerland Minera Peregrine Argentina S.A Santa Fe (Oeste) 117 Piso 4B Edificio Derby Ciudad San Juan Argentina

We investigate the geology of Altar North(Cu-Au) and Quebrada de la Mina(Au) porphyry deposits located in San Juan Province(Argentina), close to the large Altar porphyry copper deposit(995 Mt,0.35% Cu, 0.083 g/t Au), to present constraints on the magmatic processes that occurred in the parental magma chambers of these magmatic-hydrothermal systems. Altar North deposit comprises a plagioclase-amphibole-phyric dacite intrusion(Altar North barren porphyry) and a plagioclaseamphibole-biotite-phyric dacite stock(Altar North mineralized porphyry, 11.98 ± 0.19 Ma). In Quebrada de la Mina, a plagioclase-amphibole-biotite-quartz-phyric dacite stock(QDM porphyry,11.91±0.33 Ma) crops out. High Sr/Y ratios(92-142) and amphibole compositions of Altar North barren and QDM porphyries reflect high magmatic oxidation states(fO_2= NNO+1.1 to+1.6) and high fH_2O conditions in their magmas. Zones and rims enriched in anorthite(An_(37-48))), SrO(0.22-0.33 wt.%)and FeO(0.21-0.37 wt.%) in plagioclase phenocrysts are evidences of magmatic recharge processes in the magma chambers. Altar North and Quebrada de la Mina intrusions have relatively homogeneous isotopic compositions(^(87)Sr/^(86)Sr_(t)= 0.70450-0.70466, ε_(ND)(t) = +0.2 to +1.2) consistent with mixed mantle and crust contributions in their magmas. Higher Pb isotopes ratios(^(207)Pb/^(204)Pb=15.6276-15.6294) of these intrusions compared to other porphyries of the district, reflect an increase in the assimilation of high radiogenic Pb components in the magmas. Ages of zircon xenocrysts(297,210,204,69 Ma) revealed that the magmas have experienced assimilation of Miocene, Cretaceous, Triassic and Carboniferous crustal *** that precipitated sulfides in the Altar deposit may have remobilized Pb from the host rocks, as indicated by the ore minerals being more radiogenic(207Pb/204 Pb = 15.6243-15.6269) than their host intrusions. Au/Cu ratio in Altar porphyries(average Au/Cu ratio of 0.14 ×10^(-4)by weight in Altar Central)is hig

关键词： Porphyry High sulfidation epithermal Magmatic recharge Radiogenic isotopes Crustal assimilation Argentinian Andes

Fluid inclusion evidence for the involvement of organic matter in mineralization of Hg, Sb and Au deposits

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Chinese Science Bulletin 1999年第S2期44卷 197-199页

作者： SHI Jixi~1 and WANG Huayun~2 1. Open Laborator of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2. Institute of Guizhou Provincial Bureau of Geology and Mineral Resoarces, Guiyang 550001, China Open Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Institute of Guizhou Provincial Bureau of Geology and Mineral Resources Guiyang 550001 China

1 Research significance and study area GEOCHEMISTRY of organic matter in metallic ore deposits and the role of organic matter in metallogenesisare the hot subjects of research in the field of ore deposits and also a weak link in this field. Widespreadin the areas of Tongren, Danzhai, etc. in eastern Guizhou (simplified as southeastern Guizhou or Qiandongnan below) are large-sized Hg (dominant), Sb, and Au deposits, while in the areas of Qinglong,Xingren, Zhenfeng, Anlong, etc. In southwestern Guizhou (simplified as southwestern Guizhou orQianxinan below) are a number of large-sized and extremely large-sized microfine disseminated gold deposits and Sb and Hg deposits. Studies have shown that their ore-forming temperatures are estimated al<150℃ for Hg deposits, about 180℃ for Sb deposits and<200℃ for most Au deposits, respectively, allof them belonging to the typical low-temperature deposits. Not a few researchers have found bitumens

关键词： organic matter fluid inclusion epithermal Hg-Sb-Au deposit.

Geology of Gold Ore Deposits in Western Linyi of Shandong Province,China

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Global Geology 2003年第1期8卷 69-81页

作者： Tiebing Liu Qingdong Zeng Yuanchao Shen Guangming Li Institute of Geology and Geophysics Chinese Academy of SciencesInstitute of Geology and GeophysicsChinese Academy of SciencesInstitute of Geology and GeophysicsChinese Academy of SciencesInstitute of Geology and GeophysicsChinese Academy of Sciences Beijing100029 ChinaBeijing100029 ChinaBeijing100029 ChinaBeijing100029 China

Western Linyi of Shandong Province is one of the most important gold ore mineralization concentration areas. Mesozoic gold ore deposits in this area can be subdivided into two types: magmatic hydrothermal and epithermal gold deposits. The occurrences of gold ore bodies are controlled by structures. Related subvolcanic rocks can be subdivided into high potassium calc-alkali series and alkaline series. These two types of subvolcanic rocks are of different geochemical features and different sources. The high potassium calc-alkali rocks are derived from enriched mantle and contribute to the formation of magmatic hydrothermal gold ore deposits including skarn gold-copper ore deposit and porphyry gold ore deposit. Alkaline rocks are derived from lower crust and they host epithermal gold deposits. Comprehensive studies show that there is no evolutionary or transitional relationship temporally and genetically between the epithermal gold deposit and the high temperature magma hydrothermal gold deposit in the western Linyi.

关键词： magmatic hydrothermal gold deposit, epithermal gold deposit, diorite porphyry, syenite porphyry,western Linyi

Copper and Gold Mineralization Features in Deh Bala Region—South of Takestan

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Open Journal of Geology 2017年第7期7卷 1022-1046页

作者： Mohammad Yousefi Nematollah Rashidnejad Omran Mohammad Lotfi Mohammad Hassan Bazoobandi Department of Geology Faculty of Science Tarbiat Modares University Tehran Iran Islamic Azad University Tehran North Branch Tehran Iran Faculty of Science Shahid Sherafat University of Farhangian Tehran Iran

The studied area is located in 30th km of Bouien-Zahra road in Saveh in southern border of Khiaraj 1:100,000 Geology map rectangle (Danesfahan) in South of Takestan of Iran. This area is a part of volcano-plutonic belt of Urumia-Dokhtar. Rocky outcrops in this area are mainly in two types of volcanic and plutonic. Volcanic Rocks with the age of Eocene are Trachyte to trachyandesite and andesite to basalt-andesite. Plutonic stones with the age of Oligo-Miocene to Miocene are in types of quartz diorite, quartz monzonite, Monzonite and Semi-acidic volcanic domes and granite aplite. Due to having dominant fault systems with trends of NW-SE and NE-SW in an intersectional manner in this area, vein-veinlets Siliciclastic sulfide mineralization can be observed in line with the same faults. Monzonite intrusive rocks are considered as host stone of these mineralizations. The information obtained from field observations and laboratory studies confirms the main alteration along with mineralization in types of silicic and pyrite, sericite, carbonate, argillic and propylitic. Mineralogy Paragenesis in the study area includes Pyrite, chalcopyrite, bornite, colitis, malachite, hematite and goethite and the most important Gang minerals including quartz, calcite, albite, sericite, kaolinite, pyrophyllite, epidote, alunite and jarosite, and according to carried out studies, copper, gold and silver are among mineralizing elements and elements such as molybdenum, cadmium, arsenic and mercury show anomalies as accompanying and guidance elements in some of the samples. The grade of copper in this area in sulfide siliciclastic veins is 1% to 3% and the grade of gold is 130 ppm and the grade of silver is reportable from 0.5 ppm to 6 ppm. Based on the geothermometry studies of fluid inclusions, homogenization temperature from 150°C?to 300°C?and the salinity grade from 4 to 5.5 percent indicate the fact that an epithermal hydrothermal system in final stages controls the mineralization of the

关键词： Mineralization epithermal Geochemical Alteration Copper Gold South of Takestan

Diversity of Gold Deposits, Geodynamics and Conditions of Formation: A Perspective View

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Open Journal of Geology 2017年第11期7卷 1690-1709页

作者： Franck Wilfried Dongmo Nguimatsia Anthony Temidayo Bolarinwa Rose Fouateu Yongue Jean de Dieu Ndikumana Jerry Olugbenga Olajide-Kayode Olugbenga G. Olisa Maryam O. Abdu-Salam Marc Anselme Kamga Ernest Serge Djou Department of Geology Pan African University Life and Earth Science Institute-University of Ibadan Ibadan Nigeria Department of Earth Sciences University of Yaounde 1 Yaounde Cameroon

Gold occurs in a wide range of deposit types and settings. In the last decade, significant progress has been made in the definition, classification, characterization, thereby aiding understanding of the main gold deposit types. The present work aims to provide an update on the current state of knowledge on the different types of gold deposits models, geodynamics, their mode of formation and the condition suitable for their formation Several subsets of gold deposits are distinguished from one another on the bases of and their main geological models and their mode of formation described. Gold deposits of magmatic-hydrothermal origin are classified into Porphyry, epithermal, Skarn, Iron Oxide-Copper-Gold and Intrusion related deposits;those of hydrothermal origin are Orogenic, Volcanogenic Massive Sulphide deposits, and Carlin-type;while those of Sedimentary Origin are placers. In terms of the major Period of gold deposit formation, the Mesoarchean was the largest gold period. Other gold peaks followed, particularly in the Neoarchean, Paleoproterozoic and Paleozoic while numerous and diverse gold deposit types were formed during the Cenozoic *** varieties of geodynamic contexts in which each of the gold deposits are formed being explained while the conditions favourable for its formation are also being summarized. With the recent rise in the price of gold, mining companies and research centers continue to provide lighting of the key geology features of then ore-forming environments and the key geologic manifestations of the different deposit types.

关键词： Gold Tectonic Porphyry epithermal Skarns Placer

Fluid flow and mineralization of Youjiang Basin in the Yunnan-Guizhou-Guangxi area, China

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Science China Earth Sciences 2003年第Z1期46卷 99-109页

作者：王国芝胡瑞忠苏文超朱赖民 Open Laboratory of Ore Deposit Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Chengdu University of Technology Chengdu 610059 China

Comprehensive studies, based on isotope geochemistry of C, H, O, S and Sr, chronology, common element and trace element geochemistry of fluid inclusions for the epithermal Au, As, Sb and Hg deposits in the Youjiang Basin and its peripheral areas, suggested that the ore fluid was the basin fluid with abundant metallic elements and the large-scale fluid flow of the same source in the late Yenshan stage was responsible for huge epithermal mineralization and silicification. The ore fluid flowed from the basin to the platform between the basin and the platform and migrated from the inter-platform basin to the isolated platform in the Youjiang Basin. The synsedimentary faults and paleokast surface acted respectively as main conduits for vertical and lateral fluid flow.

关键词： Youjiang Basin, basin fluid, fluid flow, epithermal mineralization.