共查询到20条相似文献，搜索用时 93 毫秒
1.
Changkeng Au-Ag deposit is a newly-discovered new type precious metal deposit. N2-Ar-He systematics studies and3He/4He and δD- δ18O composition analyses show that the ore-forming fluid of the deposit is composed mainly of formation water (sedimentary brine)
but not of meteoric water, which was thought to be source of the ore-forming fluid by most previous researchers. The content
of mantle-derived magmatic water in the ore-forming fluid is quite low, usually lower than 10%. According to the source of
the ore-forming fluid, the Changkeng Au-Ag deposit should belong to sedimentary brine transformed deposits. From the Late
Jurassic to the Early Cretaceous Period, with deposition and accumulation of thick sediments in Sanzhou Basin, the formation
water in the sedimentary layers was expelled from the basin because of overburden pressure and increasing temperature. The
expelled fluid moved laterally along sedimentary layers to the margin of the basin, and finally moved upward along a gently-dipping
interlayer fault. Because of a decline in pressure and temperature, ore minerals were deposited in the fault.
Project supported by the National Natural Science Foundation of China (Grant No. 495020291, the Natural Science Foundation
of Zhongshan University, the Research Foundation of National Key Laboratory of Metallogenesis in Nanjing University (Grant
No. 039704) and the Lingnan Foundation. 相似文献
2.
《Acta Geochimica》2015,(4)
The Shuiyindong gold deposit is one of the most famous and largest Carlin-type gold deposits in China and is located in southwest Guizhou, in the eastern part of the Huijiabao anticline. The Shuiyindong's gold mineralization occurred in bioclastic limestone of the Permian Longtan Formation. Sulfur, carbon, hydrogen, oxygen, and lead isotopic compositions are reported in this paper. The properties and sources of ore-forming fluid have been discussed and a metallogenic model for the Shuiyindong gold deposit has been proposed. The d34 S values of stibnite, realgar, orpiment, pyrite from orebodies, and pyrite from quartz veins are similar to or slightly higher than the d34 S values of mantle sulfur. It is suggested that the sulfur of hydrothermal sulfides was likely of magmatic origin with minor heavy sulfur contributed from the country rocks. The measured d D values and calculated d18OH2 O values of inclusion fluid in quartz plotted within or below a magmatic hydrothermal fluid field far from the meteoric water line. This indicates that the ore-forming fluid for the main-stage gold mineralization could have been derived mainly from a magmatic source and mixed with a small amount of meteoric water. The carbon and oxygen isotopic compositions of calcites in the d18 O vs. d13 C diagram suggest that the CO2 in ore-forming fluid was derived from dissolution of bioclastic limestone and oxidation of sedimentary organic carbon in limestone. However, the d13 C values of ore-related calcites, which contain intergrown realgar and/or orpiment, are similar to those of mantle carbon. Although no igneous intrusive rock has been observed in the vicinity of the gold deposits, the possibility of mantle fluid integrated into the ore-forming fluid cannot be eliminated based on the d13 C values of ore-related calcites. The lead isotopes of sulfides are distributed near the growth curves of upper crust and orogenic belt in the plumbotectonic diagram. Their calculated Dc and Db values plotted within the magmatism field of crust-mantle subduction zone in the Dc- Db diagram. This suggests that the lead of sulfides has an intimate connection with magmatism. Our S, H, O, C, and Pb isotopic studies for the Shuiyindong Carlin-type gold deposit in Guizhou manifest a concordant possibility that the ore-forming fluid was mainly derived from magmatic fluid with minor contribution from the surrounding strata. With the integration of comprehensive geology and isotopic geochemistry, we have proposed a magmatic hydrothermal model for the origin of the Shuiyindong gold deposit. 相似文献
3.
The study results of He and Ar isotopes from fluid inclusions in pyrites formed during mineralization stage of Jinding superlarge
Pb-Zn deposit in west Yunnan, China are reported. The data show that the40Ar/36Ar and3He/4He ratios of fluid inclusions are respectively in the range of 301. 7–385. 7 and 0. 03–0.06Ra, suggesting the oreforming fluid
is a kind of air saturated meteoric groundwater. On the basis of research on coupled relationships among He, Ar, S and Pb
isotopes, the evolution history of ore-forming fluid of the deposit can be summarized as (i) air saturated meteogenic groundwater
infiltrated down and was heated→ (ii) leached S, C and radiogenic He, Ar from the basinal strata → (iii) leached Pb and Zn
from mantle-derived igneous rocks located in the bottom of the basin→ (iv) ore-forming fluid ascended and formed the deposit.
Due to this process, the isotope signatures of crustal radiogenic He, atmospheric Ar (with partial radiogenic40Ar), crustal S and mantle-derived Pb remained in the ore-forming fluid.
Project supported by A30 Project of the National Climbing Program of China and University of Manchester. 相似文献
4.
5.
浙江大桥坞矿床是赣杭火山岩铀成矿带重要的铀矿床之一。本文通过对大桥坞铀矿床铅、氢和氧同位素及前人资料的综合研究,探讨了矿床成矿流体和成矿物质来源。结果表明花岗斑岩、凝灰岩、辉绿岩、矿石中黄铁矿、蚀变围岩中黄铁矿的Ph同位素组成变化较小,可能指示它们具有相似的源区。在铅同位素构造环境判别图解中,铅同位素投影点分布范围较广,但多数集中于地幔和造山带演化线之间,偏向造山带,反映了铅的来源与岩浆活动有关。氢、氧同位素组成显示,成矿流体主要来自大气降水。成矿物质来源于壳幔混合源。 相似文献
6.
凹山铁矿是宁芜火山盆地内重要的玢岩矿床之一.为进一步厘定该矿床的成矿年龄,分析其成矿动力学背景,本文对凹山铁矿含矿辉石闪长玢岩和磁铁矿样品进行了详细的稀土元素地球化学分析,并对辉石闪长玢岩样品进行了LA-ICP-MS锆石U-Pb年龄测定.测年结果显示凹山铁矿成矿母岩的形成时代为127.6±4.4 Ma,属早白垩世,该年龄可代表凹山铁矿床的成矿年龄.成矿岩浆源自于地幔或下地壳玄武岩;盆地岩石圈减薄诱发地幔成矿物质进入地壳,成矿时代对应岩石圈减薄的高峰期. 相似文献
7.
The Tieluping silver deposit, located in the NE-trending faults within the metamorphic basement of the Xiong'er Mountain, is a typical altered fracture type deposit. Its ore-forming process includes three stages with temperatures concentrated at 373°C, 223°C and 165°C respectively. With δD=90‰,\(\delta ^{13} C_{CO_2 } \)=2.0‰ and δ{si18}O=8094‰, the early stage fluid was generated from reworking and metamorphism of the carbonate rich formation; the late one, with δD=?70‰,\(\delta ^{13} C_{CO_2 } \)=-1.2‰, δ18O=1.89‰, was meteoric hydrothermal solution; and the middle. δD=?109‰,\(\delta ^{13} C_{CO_2 } \)=0.1‰, δ18O=1.79‰, might be a hybrid mixed by reworking-metamorphic fluid and meteoric hydrothermal solution. Crystallized rapidly in the condition of fluid-boiling and fluid-mixing, the middle stage minerals have far more fluid inclusions with higher content of ions, higher ratios of H2O/CO2 and KN/MC. Consequently, they have much more ore elements such as gold compared with those of the early and late stages. It was the northward intracontinental subduction along the Machaoying fault during the Mesozoic collision between the South China and North China paleocontinents that intrigued large-scale fluidization and magmatism and led to the appearance of more than 10 large and medium hydrothermal deposits, including the Tieluping silver deposit. The study on ore-forming fluidization of the Tieluping silver deposit proves the CPMF model. 相似文献
8.
The Tieluping silver deposit, located in the NE-trending faults within the metamorphic basement of the Xiong'er Mountain, is a typical altered fracture type deposit. Its ore-forming process includes three stages with temperatures concentrated at 373°C, 223°C and 165°C respectively. With δD=90‰,\(\delta ^{13} C_{CO_2 } \)=2.0‰ and δ{si18}O=8094‰, the early stage fluid was generated from reworking and metamorphism of the carbonate rich formation; the late one, with δD=−70‰,\(\delta ^{13} C_{CO_2 } \)=-1.2‰, δ18O=1.89‰, was meteoric hydrothermal solution; and the middle. δD=−109‰,\(\delta ^{13} C_{CO_2 } \)=0.1‰, δ18O=1.79‰, might be a hybrid mixed by reworking-metamorphic fluid and meteoric hydrothermal solution. Crystallized rapidly in the condition of fluid-boiling and fluid-mixing, the middle stage minerals have far more fluid inclusions with higher content of ions, higher ratios of H2O/CO2 and KN/MC. Consequently, they have much more ore elements such as gold compared with those of the early and late stages. It was the northward intracontinental subduction along the Machaoying fault during the Mesozoic collision between the South China and North China paleocontinents that intrigued large-scale fluidization and magmatism and led to the appearance of more than 10 large and medium hydrothermal deposits, including the Tieluping silver deposit. The study on ore-forming fluidization of the Tieluping silver deposit proves the CPMF model.
相似文献9.
Sources of ore-forming fluids and metallic materials in the Jinwozi lode gold deposit, eastern Tianshan Mountains of China 总被引：4，自引：0，他引：4
This paper presents gas compositions and H-, O-isotope compositions of sulfide- and quartz-hosted fluid inclusions, and S-, Pb-isotope compositions of sulfide separates collected from the principal Stage 2 ores in Veins 3 and 210 of the Jinwozi lode gold deposit, eastern Tianshan Mountains of China. Fluid inclusions trapped in quartz and sphalerite are dominantly primary. H- and O-isotopic compositions of pyrite-hosted fluid inclusions indicate two major contributions to the ore-forming fluid that include the degassed magma and the meteoric-derived but rock 18O-buffered groundwater. However, H- and O-isotopic compositions of quartz-hosted fluid inclusions essentially suggest the presence of groundwater. Sulfide-hosted fluid inclusions show considerably higher abundances of gaseous species CO2, N2, H2S, etc. Than quartz-hosted ones. The linear trends among inclusion gaseous species reflect the mixing tendency between the gas-rich magmatic fluid and the groundwater. The relative enrichment of gaseous species in sulfide-hosted fluid inclusions, coupled with the banded ore structure indicating alternate precipitation of quartz with sulfide minerals, suggests that the magmatic fluid has been inputted to the ore-forming fluid in pulsation. Sulfur and lead isotope compositions of pyrite and galena separates indicate an essential magma derivation for sulfur but the multiple sources for metallic materials from the mantle to the bulk crust. 相似文献
10.
Most metallic minerals in ore deposits are sulfides. When a sulfide mineral coexists with rock-forming minerals, its solubility
is distinctly different from itself alone. The change in dissolution character of a mineral with coexisting rock-forming minerals
leads to particular geochemical behavior. The concept of solubility of a metallic mineral with coexisting rock-forming minerals
and its theory and model of calculation are put forward. Taking Tianmashan Cu-Au ore deposit of sulfide minerals in Tongling
district as an example, solubilities of some metallic minerals with other coexisting minerals, such as pyrite or chalcopyrite
with quartz (representing sandstone) or calcite (representing limestone), are calculated. The results show the mechanism of
ore-forming processes. As the ore-forming fluid flows through sandstone, it dissolves pyrite in the sandstone at first, then
transports the iron and sulfur to the interface between sandstone and limestone and eventually precipitates them on the interface. 相似文献
11.
Ore-forming fluid and metallization of the Huanggangliang skarn Fe-Sn deposit, Inner Mongolia 总被引：2，自引：0，他引：2
Two kinds of inclusions, fluid-melting inclusion and gas-liquid inclusion, are present in the Huanggangliang deposit in eastern
Inner Mongolia. Temperature ranges from 1050°C of fluid-melting inclusion to 150°C of liquid inclusion. Away from intrusion,
the inclusions of orebodies intend to be characterized by simpler type, lower temperature and lower salinity, as well as weakened
relation to intrusion. The metallization of the Huanggangliang deposit is characterized by multiple activities of ore-forming
fluid, multi-source, multi-stage accumulation of ore-forming material, F-rich environment, enrichment of F, organic gas, CO2 and N2, and involving of residual magma. 相似文献
12.
Re-Os isotope dating of molybdenites in the Huang-shaping Pb-Zn-W-Mo polymetallic deposit, Hunan Province, South China and its geological significance 总被引：11，自引：0，他引：11
YAO JunMing HUA RenMin QU WenJun QI HuaWen LIN JinFu & DU AnDao State Key Laboratory of Crust-Mantle Evolution Mineralization Department of Earth Sciences Nanjing University Nanjing China Institute of Rock Mineral Analysis Chinese Academy of Geological Sciences Beijing China Institute of Geochemistry Chinese Academy of Sciences Guiyang China Department of Resources Environment Engineering Guilin Institute of Technology Guilin China 《中国科学D辑(英文版)》2007,50(4):519-526
The large-scale Huangshaping Pb-Zn-W-Mo polymetallic deposit is located in the central Nanling min- eralization zone, South China. Six molybdenite samples from the Huangshaping deposit were selected for Re-Os isotope measurement in order to define the mineralization age of the deposit. It yields a Re-Os isochron age of 154.8±1.9 Ma (2σ ), which is in accordance with the Re-Os model ages of 150.9― 156.9 Ma. This age is about 7 Ma younger than their host granite porphyry, which was dated as 161.6±1.1 Ma by zircon U-Pb method using LA-ICPMS. All these ages demonstrate that the Huang- shaping granite and related Pb-Zn-W-Mo deposit occurred in the middle Yanshanian period, when many other granitoid and related ore deposits emplaced and formed, e.g. the Qitianling granite and Furong tin deposit, the Qianlishan granite and giant Shizhuyuan W-Sn-Mo-Bi deposit and Jinchuantang Sn-Bi deposit in the nearby area. They constitute the main part of the magmatic-metallogenic belt of southern Hunan, and represent the large-scale metallogeny in middle Yanshanian in the area. The lower rhenium content in molybdenite of Huangshaping deposit suggests that the ore-forming material was mainly of crust origin. 相似文献
13.
The Qinling Carlin-type gold deposit belt is the second largest Carlin-type gold ore concentrated area in the world and occurs in Mesozoic intracontinental collisional orogen, contrasting to the Carlin-type gold deposits in the Basin and Range province in Cenozoic active continental margin of West America. With ore-forming ages focussed at the range of 197.45–129.45 Ma, its metallogenic geodynamic background was the decompression-pyrogenation regime at the transition stage from collisional compression to extension, indicating that gold mineralization synchronized with the Mesozoic continental collision. Geochemical studies discover that ore fluids and materials mainly came from the Hercynian-Indosinian tectonic layer. Mesozoic intracontinental subduction of Hercynian-Indosinian association along the Shuanghe-Gongguan fault led to the formation of Jinlongshan-Qiuling gold deposits. Accordingly, the tectonic metallogenic model is established for Qinling-pattern Carlin-type gold deposits. 相似文献
14.
SHEN Ping SHEN Yuanchao LIU Tiebing LI Guangming & ZENG Qingdong Institute of Geology Geophysics Chinese Academy of Sciences Beijing China 《中国科学D辑(英文版)》2005,48(11)
The Kuoerzhenkuola gold field (including the Kuo- erzhenkuola and the Buerkesidai gold deposits), lo- cated 68 km east of Jimunai County in northern Xing- jiang, China, is an important component of the Sawuer gold belt which is the eastward extending part of the Zarma-Sawur gold-copper belt in Kazakhstan. Some studies are concerned with the geology of the gold ores[1―3], the associated volcanic rocks[4], radiogenic isotope[5―8], and the ore-forming environment[8]. Most researchers inferr… 相似文献
15.
This paper presents gas compositions and H-, O-isotope compositions of sulfide- and quartz-hosted fluid inclusions, and S-, Pb-isotope compositions of sulfide separates collected from the principal Stage 2 ores in Veins 3 and 210 of the Jinwozi lode gold deposit, eastern Tianshan Mountains of China. Fluid inclusions trapped in quartz and sphalerite are dominantly primary. H-and O-isotopic compositions of pyrite-hosted fluid inclusions indicate two major contributions to the ore-forming fluid that include the degassed magma and the meteoric-derived but rock 18O-buffered groundwater. However, H- and O-isotopic compositions of quartz-hosted fluid inclusions essentially suggest the presence of groundwater. Sulfide-hosted fluid inclusions show considerably higher abundances of gaseous species CO2, N2, H2S, etc. than quartz-hosted ones. The linear trends among inclusion gaseous species reflect the mixing tendency between the gas-rich magmatic fluid and the groundwater. The relative enrichment of gaseous species in sulfide-hosted fluid inclusions, coupled with the banded ore structure indicating alternate precipitation of quartz with sulfide minerals, suggests that the magmatic fluid has been inputted to the ore-forming fluid in pulsation. Sulfur and lead isotope compositions of pyrite and galena separates indicate an essential magma derivation for sulfur but the multiple sources for metallic materials from the mantle to the bulk crust. 相似文献
16.
This paper presents gas compositions and H-, O-isotope compositions of sulfide- and quartz-hosted fluid inclusions, and S-, Pb-isotope compositions of sulfide separates collected from the principal Stage 2 ores in Veins 3 and 210 of the Jinwozi lode gold deposit, eastern Tianshan Mountains of China. Fluid inclusions trapped in quartz and sphalerite are dominantly primary. H-and O-isotopic compositions of pyrite-hosted fluid inclusions indicate two major contributions to the ore-forming fluid that include the degassed magma and the meteoric-derived but rock 18O-buffered groundwater. However, H- and O-isotopic compositions of quartz-hosted fluid inclusions essentially suggest the presence of groundwater. Sulfide-hosted fluid inclusions show considerably higher abundances of gaseous species CO2, N2, H2S, etc. than quartz-hosted ones. The linear trends among inclusion gaseous species reflect the mixing tendency between the gas-rich magmatic fluid and the groundwater. The relative enrichment of gaseous species in sulfide-hosted fluid inclusions, coupled with the banded ore structure indicating alternate precipitation of quartz with sulfide minerals, suggests that the magmatic fluid has been inputted to the ore-forming fluid in pulsation. Sulfur and lead isotope compositions of pyrite and galena separates indicate an essential magma derivation for sulfur but the multiple sources for metallic materials from the mantle to the bulk crust.
相似文献17.
The Xiaoxinancha Au-rich copper deposit is one of important Au-Cu deposits along the continental margin in Eastern China. The deposit consists of two sections: the Beishan mine (North), composed of altered rocks with veinlet-dissemination sulfides and melnicovite-dominated sulfide-quartz veins, and the Nanshan mine (South), composed of pyrrhotite-dominated sulfide-quartz veins and pure sulfide veins. The isotope compositions of noble gases extracted from fluid inclusions in ore minerals, i.e. ratios of 3He/4He, 20Ne/22Ne and40Ar/36Ar are in the ranges of 4.45―0.08 Ra, 10.2―8.8 and 306―430, respectively. Fluid inclusions in minerals from the Nanshan mine have higher 3He/4He and 20Ne/22Ne ratios whereas those from the Beishan mine have lower 3He/4He ratios. The analysis of origin, and evolution of the ore fluids and its relations with the ore-forming stages and the ages of mineralization suggests that the initial hydrothermal fluids probably come from the melts generated by partial melting of oceanic crust with the participation of fluids from the mantle (mantle-plume type)/aesthenosphere. This also corresponds to the continental margin settings during the subduction of Izanagi ocaneic plate towards the palaeo-Asian continent (123―102 Ma). The veinlet-dissemination ore bodies of the Beishan mine were formed through replacement and crystallization of the mixed fluids generated by mixing of the ascending high-temperature boiling fluid with young crustal fluid whereas the melnicovite-dominated sulfide-quartz veins were formed subsequently by filling of the high-temperature ore fluid in fissures. Pyrrhotite-dominated sulfide-quartz veins in the Nanshan mine were formed by filling-deposition-crystallization of the moderate-temperature ore fluids and the pure sulfide veins were formed later by filling-deposition-crystallization of ore substance-rich fluids after boiling of the moderate-temperature ore fluids. The metallogenic dynamic processes can be summarized as: (1) formation of fluidand ore substance-bearing Adakitic magma by degassing, dewatering and partial melting during subduction of the Izanagi plate; (2) separation and formation of ore fluids from the Adakitic magma; and (3) success-sive ascending of the ore fluids and final formation of the Au-rich Cu deposit of veinlet-dissemination and vein types by secondary boiling. 相似文献
18.
This paper reveals the physicochemical properties such as component, formulation, genesis, tem- perature, pH, Eh, salinity and pressure of all main alteration fluid of interlayer oxidation zone sand- stone-type uranium deposits after studying the geologic process and geochemistry of internal typical sandstone-type uranium deposits such as Shihongtan deposit in the Turpan-Hami basin, 512 deposit in the Yili basin, Dongsheng deposit in the Ordos basin. The composition of fluid can be divided into two parts based on the analysis of inclusion one can be affirmed as atmospheric water with ordinary temperature epigenesist according to the character of hydrogen and oxygen isotope of inclusion, the other is natural gas containing gaseous hydrocarbon like CH4, and CO2 as well as a little H2S, CO, H2, N2 and so on, it always contains a small quantity of hydrocarbon liquid in petroliferous basins. The fluid property of oxidation alteration zone is always oxidation alkaline, and neutrality or weak acid-weak alkaline and reducibility during the metallizing process, but at secondary reduction or deoxidization zone it becomes strong reduction alkaline. Oxygenic groundwater in the fluid is the activate and mig- ratory medium of uranium element, but the gaseous hydrocarbon like CH4 as well as H2, H2S, CO from natural gas is the important sedimentary reducer of uranium mineral; the transformation of pH,Eh in fluid environment is the main reason for the formation of uranium metallization. 相似文献
19.
40Ar/39Ar and Rb-Sr isochron dating of the gold deposits on northern margin of the Jiaolai Basin, Shandong, China 总被引：1，自引：0，他引：1
Lianchang Zhang Yuanchao Shen Tiebing Liu Qingdong Zeng Guangming Li Houmin Li 《中国科学D辑(英文版)》2003,46(7):708-718
The Pengjiakuang, Dazhuangzi and Fayunkuang gold deposits, located on the northern margin of the Mesozoic Jiaolai Basin, east
of Shandong Province, are controlled by a low-angle normal fault. Gold ores are typically brecciated, veinlet and disseminated.
The Ar-Ar and Rb-Sr isochron dating methods were adopted to date ores and lamprophyre dike. The results indicate that the
age of the Pengjiakuang gold deposit is 117.33–118.42 Ma, that of the Dazhuangzi gold deposit is 117.39 Ma, and that of the
Fayunkuang gold deposit is (128.49±7.2) Ma. The consistency in metallogenic age between the gold deposits on the margin of
the Jiaolai Basin and the gold deposits (115–126 Ma) of the northern uplift area suggests that both were formed in the same
metallogenic period. That is to say, the large-scale metallogeny of the Jiaodong region took place in late-Yanshannian ((120±10)
Ma). 相似文献
20.
江西省万载县野猫冲铜矿床为中低温热液（成矿流体）沿构造破碎带蚀变-蚀变岩型铜矿床。在地表地质调查、钻孔岩芯考察及岩矿鉴定的基础上,对野猫冲铜矿控矿构造进行详细研究,表明北东东向大型叠瓦状推（滑）覆构造控制矿区内各地质单元的延深与展布,北东向韧性剪切变形带控制矿区铜金矿体的展布,矿体呈似层状赋存于韧性剪切断裂之间的次级层间破碎带和小断裂带内,带内发育较强的动热变质,硅化、绢云母化和绿泥石化发育。矿石以黄铜矿为主,贫硫,成矿流体具有多期次的活动、叠加改造的特点。上栗-潭埠-宜丰断裂带自西至东已发现20余处铜多金属矿床（点）,显示该带具有巨大找矿潜力。 相似文献