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1.
本文研究了浙江省诸暨至龙泉一带金矿床的铅同位素地球化学特征。通过研究铅同位素组成、源区特征值和模式年龄,对该区金矿床得出以下两点认识:1.该区金矿床铅同位素组成在区域上具有一定的变化趋势,并可分为二大类,即正常铅和弱放射性成因异常铅,它们反映了一定的物源特征;2.该区金矿床的区域成矿时代为400—700Ma,结合区域成矿地质特征,可以证明该区金矿床主要为变质热液矿床。 相似文献
2.
东天山康古尔金矿床成矿物源的同位素地球化学特征 总被引：5，自引：0，他引：5
康古尔金矿床属晚古生代火山岩区剪切带蚀变岩型金矿。同位素地球化学研究表明,矿石中铅为正常铅,热液系统硫同位素组成为陨石硫型,矿石中碳、钕同位素组成具深源特征,同时矿石与火山岩围岩中的Ｓｉ、Ｓｒ、Ｓ、Ｐｂ等同位素组成相近,说明成矿物质主要来自矿体围岩———火山岩,晚期有少量来自矿区附近的侵入岩。铅、锶同位素组成反映成矿过程中也有少量壳源物质的加入。 相似文献
3.
Metallogenic Epoch of Nonferrous Metallic and Silver Deposits in the Jiaodong Peninsula, China and its Geological Significance 总被引：2，自引：1，他引：1
SONG Mingchun WANG Shanshan YANG Lixin LI Jie LI Shiyong DING Zhengjiang 《《地质学报》英文版》2017,91(4):1305-1325
As China's most important gold-producing district,the Jiaodong Peninsula also contains copper,lead-zinc,molybdenum(tungsten),and other nonferrous metal ore deposits,but the space-time and genetic relationships with gold deposits remain uncertain.To investigate the temporal relationship between these nonferrous metal and gold ore deposits,We collected the samples from a number of nonferrous metallic and silver deposits and metallogenetic rock bodies in the eastern Jiaodong Peninsula for isotopic dating.The results show that the Re-Os isotopic model ages of the Lengjia molybdenum deposit in Rongcheng range from 114.5± 1.8 Ma to 112.6± 1.5 Ma,with an average age of 113.6± 1.6Ma;the LA-ICP-MS ~(206)Pb/~(238)U ages of 33 zircons in the sericitization porphyritic monzogranite that hosts the Tongjiazhuang silver deposit in Rongcheng range between 122 Ma and 109 Ma,with a weighted mean age of 116.04± 0.95 Ma;the LA-ICP-MS ~(206)Pb/~(238)U ages of 31 zircons in the copper metallogenic pyroxene monzodiorite that hosts the Kuangbei copper deposit in Rongcheng range from126 Ma to 106 Ma,with a weighted mean age of 116.6± 1.7 Ma;and the LA-ICP-MS ~(206)Pb/~(238)U ages of19 zircons in the pyroxene monzodiorite surrounding the Dadengge gold and multimetal deposit in Weihai range from 113 Ma to 110 Ma,with a weighted mean age of 111.7± 0.6 Ma.All these results indicate that the metallogenic ages of the silver and nonferrous metallic deposits in the Jiaodong Peninsula are in a limited range from 118 Ma to 111 Ma.Previous studies have demonstrated that the isotopic ages of gold deposits in the Jiaodong Peninsula range from 123 Ma to 110 Ma,while Weideshanian magmatism occurred between 126 Ma to 108 Ma.Both these ranges are grossly consistent with the metallogenic ages of silver and nonferrous metallic deposits in this study,suggesting that the large-scale mineralization occurred in the Early Cretaceous when magmatic activities were strong.This epoch may be linked to the lithosphere thinning and the thermo-upwelling extension in eastern China at that time.In addition,field investigation also shows that gold and nonferrous metallic deposits are distributed nearby the Weideshanian granite,with the nonferrous metallic deposits lying within or surrounding the granite pluton and the gold deposits outside the granite pluton.We propose the following mineralization scenario:In the Early Cretaceous,an intensive lithospheric extension induced partial melting and degassing of the metasomatized lithospheric mantle,which resulted in the formation of mantle-derived fluids enriched in metal elements.During the rapid process of magma ascent and intrusion,crust-derived fluids were activated by the magmatic thermal dome and served to further extract ore-forming materials from the crust.These fluids may have mixed with the mantle-derived fluid to form a crust-mantle mixing-type ore-forming fluid.The high-temperature conditions in the center or in contact with the granitic magmatic thermal dome would have been favorable for the formation of porphyry-type,skarn-type,and hydrothermal-vein-type ores,thus forming a series of Mo(W),Cu,and Pb-Zn deposits in the mid-eastern Jiaodong Peninsula.In contrast,the medium-to low-temperature conditions in the periphery of the magmatic thermal dome would have favored the deposition of gold(silver) ores under the appropriate physiochemical and structural conditions.The metallogenic epoch of the molybdenum,copper,and silver deposits,and their spatio-temporal and genetic relations to the gold deposits,as demonstrated in this study,not only provide important insights to the study of regional metallogeny,our understanding of the metallogenesis of the Jiaodong type gold deposit,and the geodynamic background of the large-scale mineralization in the Jiaodong Peninsula,but also have practical value in guiding the mineral exploration. 相似文献
4.
5.
Stable Isotopic Geochemical and Geochronological Constraints on the Formation of the Shihu Gold Deposit: The Intracontinental Metallogeny of the Taihang Tectonic Belt,Eastern China 
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下载免费PDF全文 The Early Cretaceous Shihu gold deposit is located in the northern segment of the Taihang Tectonic belt, which extends across the central part of the North China Craton. The deposit is hosted predominantly by the Archean metamorphic crystalline units, and is spatially and temporally related to quartz diorite porphyry present extensively throughout the gold deposit. We studied the geology, geochronology and stable isotopic geochemistry. Zircon U–Pb LA–ICP–MS ages of the quartz diorite porphyry at deposit range from 134 ± 1 to 131 ± 2 Ma, which are coeval and probably genetically related to the mineralization. The majority of the sulfides of the gold deposit have δ34S values ranging from ?1 to 2‰, which suggest an homogeneous magmatic source. In addition, the isotopic compositions of δ18Ofluid and δ18Dfluid vary from 2.1 to 7.0‰ and ?93 to ?65‰, respectively, suggesting that the magmatic fluids mingled with meteoric water. The Pb isotopic analyses reveal that both the ore‐forming materials and the quartz diorite porphyry originated from the lower crust and may have been mixed with mantle material. The 87Sr/86Sri and 143Nd/144Nd (143Nd/144Nd)i ratios for the quartz diorite porphyry demonstrate that there was mixing of two end‐member (crust and the mantle) isotopic compositions. These results suggest that the ore‐forming fluids and materials were derived from lower‐crustal melting induced by mantle processes. Processes associated with the formation of the Shihu gold deposit differ significantly from those that characterize orogenic gold deposits, and instead are representative of formation in an intracontinental tectonic environment. 相似文献
6.
论治岭头金银矿床的成因 总被引：2，自引：0，他引：2
治岭头金银矿床矿体为含冰长石、蔷薇辉石的玉髓状石英脉体,矿石具环带状构造,围岩蚀变具典型的浅成低温热液蚀变特征,成矿流体是一种低盐度、近中性的还原性流体.矿床硫、铅、氢、氧、碳同位素研究表明,成矿物质主要来源于地下深部（甚至上地幔）,成矿热液表现出低温热液演化特点.成矿作用与加里东晚期浅成岩浆侵入活动有内在的成因联系.治岭头金银矿床属浅成低温热液（次火山热液）型金银矿床 相似文献
7.
《International Geology Review》2012,54(5):572-592
The Dexing porphyry copper deposit, part of the circum-Pacific porphyry copper ore belt, is the largest porphyry copper deposit in China. We present new LA–ICP–MS zircon U–Pb and molybdenite Re–Os dating, bulk-rock elemental and Sr–Nd–Pb isotopic as well as in situ zircon Hf isotopic geochemistry for these ore-bearing porphyries, in an attempt to better constrain their petrogenesis. LA–ICP–MS zircon U–Pb dating shows that the Dexing porphyries were emplaced in the early Middle Jurassic (～171 Ma); molybdenite Re–Os dating indicates that the associated Cu–Mo mineralization was contemporaneous (～171 Ma) with the igneous intrusion. The rocks are mainly high-K calc-alkaline and show adakitic affinities, including high Sr and low Y and Yb contents, high Sr/Y and La/Yb ratios, and high Mg# (higher than pure crustal melts). These porphyries have initial 87Sr/86Sr ratios of 0.7044?0.7047, ?Nd(T) values of –1.5 to?+0.6, and ?Hf(T) (in situ zircon) values of?+2.6 to?+4.6. They show unusually radiogenic Pb isotopic compositions with initial 206Pb/204Pb ratios up to 18.41 and 207Pb/204Pb up to 15.61. These isotopic compositions are distinctly different from either Pacific MORB or Yangtze lower crust but are similar to the subducting sediments in the western Pacific trenches. Detailed elemental and isotopic data suggest that the Dexing porphyries were emplaced in a continental arc setting coupled with westward subduction of the palaeo-Pacific plate. Partial melting involved the subducted slab (mainly the overlying sediments), with generated melts interacting with the lithospheric mantle wedge, thereby forming the investigated high-K calc-alkaline porphyry magmas. 相似文献
8.
The Liziyuan gold deposit, situated on the south side of the Shangdan suture zone, West Qinling Orogen, occurs in metamorphic volcanic rocks(greenschist facies) of the early Paleozoic Liziyuan Group and in Indosinian Tianzishan monzogranite. Orebodies in the Liziyuan gold field are controlled by the ductile-brittle shear zone, and by thrusting nappe faults related to the Indosinian orogeny. In detail, this paper analyzed the geological characteristics of the Liziyuan gold field, and the Pb isotopes of the Lziyuan host rocks, granitoids(Tianzishan monzogranite and Jiancaowan syenite porphyry), sulfides, and auriferous quartz veins by multiple-collector inductively coupled plasma mass spectrometry(MC-ICPMS). In addition, previous data on the sulfur, hydrogen, and oxygen isotopes were employed to discuss the possible sources of the ore-forming fluids and materials, and to further understand the tectonic setting of the Liziyuan gold deposit. The sulfides and their host rocks(Lziyuan Group), Tianzishan monzogranite and Jiancaowan syenite porphyry, and auriferous quartz veins have similar Pb isotopic compositions.Zartman's plumbotectonic model diagram shows that most of the data for the deposit fall near the orogenic Pb evolutionary curve or within the area between the orogenic and mantle Pb evolutionary curves. In the△β-△γ diagram, which genetically classifies the lead isotopes, most of the data fall within the range of the subduction-zone lead mixed with upper crust and mantle. This indicates that a complex source of the ore lead formed in the orogenic environment. The δ~(34)S values of the sulfides range from 3.90 to 8.50‰(average6.80‰), with a pronounced mode at 5.00‰-8.00‰. These values are consistent with that of orogenic gold deposits worldwide, indicating that the sulfur sourced mainly from reduced metamorphic fluids. The isotopic hydrogen and oxygen compositions support a predominantly metamorphic origin of the oreforming fluids, with possible mixing of minor magmatic fluids, but the late stage was dominated by meteoric water. The characteristics of the Liziyuan gold deposit formed in the Indosinian orogenic environment of the Qinling Orogen are consistent with those of orogenic gold deposits found worldwide. 相似文献
9.
西藏雄村斑岩型铜金矿集区是近年来西藏冈底斯斑岩铜矿带内发现的一处超大型铜金矿集区,其形成于与新特提斯洋向北的洋内俯冲作用有关的岛弧环境,成矿时代为中侏罗世。该矿集区位于冈底斯火山-岩浆弧的中段南缘,其南侧紧邻日喀则弧前盆地,目前探明Ⅰ(原命名为雄村铜矿床)、Ⅱ、Ⅲ号铜金矿体规模达大型-超大型,同时还存在多个矿化异常带。本文以雄村Ⅰ号矿体为研究对象,对雄村Ⅰ号矿体含矿斑岩、赋矿凝灰岩和主要硫化物的硫、铅同位素开展研究,结果表明:①含矿斑岩、赋矿凝灰岩和主要硫化物具有较为一致的硫同位素组成,δ34SCDT变化范围为-3.5‰～2.7‰,平均-1.07‰,十分接近于零,塔式分布效应显著,硫可能主要来自地幔;②含矿斑岩、赋矿凝灰岩和主要硫化物具有相对一致的铅同位素组成,均以放射性成因铅含量低为特征,206Pb/204Pb、207Pb/204Pb和208Pb/204Pb变化范围分别为18.369～18.752、15.473～15.589和38.389～39.1531,位于地幔与造山带铅演化线之间,并且相对靠近地幔铅演化线,显示出铅主要来源于地幔,可能有少量地壳物质的混染。通过西藏冈底斯斑岩铜矿带碰撞造山环境和岛弧环境(以雄村Ⅰ号矿体为代表)斑岩型铜矿床的硫、铅同位素组成特征对比,认为两者的成矿物质来源是相似的,碰撞造山环境的地壳物质混染较强烈,而岛弧环境的地壳物质混染较弱。 相似文献
10.
云南大平掌铜多金属矿床成矿作用 总被引：4，自引：1，他引：3
云南大平掌矿床位于澜沧江火山岩带的中南段,左侧是澜沧江和酒房深大断裂。矿区内发育一套形成于岛弧环境的上石炭统细碧-石英角斑岩系,矿体产于流纹质火山岩中,产状与火山岩一致。矿体分2类,上部为块状矿体,下部为细脉-浸染状矿体。矿床内热液蚀变发育,特别是浸染状矿体中更强,并从矿体中心向外侧形成分带。具工业意义的Cu、Pb、Zn等元素以硫化物形式产出。S、Pb、Sr、Nd等同位素成分表明,成矿物质来源于地幔-下地壳。尽管矿体受后期构造破坏强烈,但综合研究表明,该矿床仍具有世界上绝大多数火山成因块状硫化物矿床的共同性。它与区内类似矿床的差异性,为在该区寻找火山成因块状硫化物矿床开辟了新方向。 相似文献
11.
《Resource Geology》2018,68(3):227-243
As a newly discovered medium‐sized deposit (proven Pb + Zn resources of 0.23 Mt, 9.43% Pb and 8.73% Zn), the Dongzhongla skarn Pb–Zn deposit is located in the northern margin of the eastern Gangdese, central Lhasa block. Based on the geological conditions in this deposit of ore‐forming fluids, H, O, C, S, Pb, Sr, and noble gas isotopic compositions were analyzed. Results show that δ18OSMOW of quartz and calcite ranged from −9.85 to 4.17‰, and δDSMOW ranged from −124.7 to −99.6‰ (where SMOW is the standard mean ocean water), indicating magma fluids mixed with meteoric water in ore‐forming fluids. The δ13CPDB and δ18OSMOW values of calcite range from −1.4 to −1.1‰ and from 5.3 to 15.90‰, respectively, show compositions consistent with the carbonate limestone in the surrounding rocks, implying that the carbon was primarily sourced from the dissolution of carbonate strata in the Luobadui Formation. The ore δ34S composition varied in a narrow range of 2.8 to 5.7‰, mostly between 4‰ and 5‰. The total sulfur isotopic value δ34S was 4.7‰ with characteristics of magmatic sulfur. The 3He/4He values of pyrite and galena ranged from 0.101 to 5.7 Ra, lower than those of mantle‐derived fluids (6 ± 1 Ra), but higher than those of the crust (0.01–0.05 Ra), and therefore classified as a crust–mantle mixed source. The Pb isotopic composition for 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values of the ores were in the ranges of 18.628–18.746, 15.698–15.802, and 39.077–39.430, respectively, consistent with the Pb isotopic composition of magmatic rocks in the deposit, classified as upper‐crust lead. The ore lead was likely sourced partially from the crustal basement of the Lhasa Terrane. The initial (87Sr/86Sr)i value from five sulfide samples ranged from 0.71732 to 0.72767, and associated ore‐forming fluids were mainly sourced from the partial melting of the upper‐crust materials. Pb isotopic compositions of ore sulfides from the Dongzhongla deposit are similar to that of the Yuiguila and Mengya'a deposit, indicating that they have similar sources of metal‐rich ore‐forming solution. According to basic skarn mineralogy, the economic metals, and the origin of the ore‐forming fluids, the Dongzhongla deposit was classified as a skarn‐type Pb–Zn deposit. 相似文献
12.
通过对赋存于麻山群老地层且与岩浆热液有关的老柞山金矿床的矿床地质及稳定同位素地球化学特征的研究分析,得出老柞山金矿床与岩浆岩、构造和麻山群密切相关,岩浆热液提供物源和热源,区内成矿物质具有深源性且来源单一的特点。 相似文献
13.
西藏班公湖—怒江成矿带南侧矽卡岩型铜多金属矿床S、Pb同位素组成及成矿物质来源 总被引：1，自引：0，他引：1
班公湖—怒江成矿带南侧分布着多个与班公湖—怒江洋南向俯冲、碰撞、后碰撞伸展各阶段有关的矽卡岩型铜多金属矿床,目前对单个矿床的研究较多,而对形成于不同环境下的矿床之间的对比研究较少。本文通过对该成矿带南侧典型矽卡岩型铜多金属矿床的S、Pb同位素特征进行较为系统的总结,并结合前人对辉钼矿Re同位素、成矿岩体地球化学特征、成岩成矿时代及区域构造演化等研究的成果,对不同构造背景下所形成的4个矿床的成矿物质来源进行对比研究。研究表明：舍索矿床的S同位素具有明显的双峰式分布,为壳幔混合来源,而区内典型矿床的S同位素显示从班公湖—怒江洋南向俯冲（舍索）→碰撞（嘎拉勒、尕尔穷）→后碰撞（班戈日阿）逐渐富集重硫的特征;Pb同位素显示舍索较其他矿床更富集放射成因Pb,舍索、班戈日阿矿床成矿物质主要来源于念青唐古拉群结晶基底,而同碰撞期形成的嘎拉勒、尕尔穷矿床则显示了明显的壳幔混合来源的特征,念青唐古拉群结晶基底对尕尔穷矿床的成矿物质有少量贡献。此外,斑岩-矽卡岩复合型矿床的成矿物质来源具有壳幔混源的特征,而单一的矽卡岩型矿床以上地壳来源为主。 相似文献
14.
Sen Wang Da Zhang Tengda Yu Ganguo Wu Yongjun Di Yaoyao Zhang Jiming Yao 《Resource Geology》2021,71(1):63-79
The Luoyang Fe polymetallic deposit is a well‐known Makeng‐type ore deposit in a late Paleozoic basin in southwest Fujian, southeast China. To investigate the generation of Makeng‐type Fe deposits, we conducted an integrated study of geochronology and S–Pb–O–H isotope compositions of the Luoyang Fe deposit. The LA–ICP–MS zircon U–Pb ages of the granite and Re–Os ages of the molybdenite suggest that the emplacement of the granite was coeval with the mineralization of the Luoyang deposit at 133–131 Ma. The H–O and S–Pb isotope compositions indicate that the metallogenic material of the Luoyang deposit had a magmatic hydrothermal source, and was derived mainly from the upper crust with a low degree of contamination of mantle material. The Pb isotope analyses of the ore minerals show that the Luoyang Fe deposit formed in an orogenic setting. 相似文献
15.
Omai is a high tonnage, low-grade, world-class gold deposit located in the Paleoproterozoic Guiana Shield. It is the second
most important gold deposit in the Guiana Shield (after Las Cristinas, Venezuela), and one of the largest in South America
(4.0 million oz.). Sm-Nd and Sr isotope data are presented for host rocks and for scheelite from auriferous quartz-carbonate-scheelite-sulfide-telluride
veins from the Omai deposit. Gold-bearing veins are hosted by the Paleoproterozoic Barama-Mazaruni Supergroup, a greenstone
belt sequence consisting of mafic volcanic rocks interbedded with sedimentary rocks that are intruded by quartz-feldspar porphyry
and rhyolite dikes. This lithologic sequence was folded and metamorphosed to lower greenschist facies during the Paleoproterozoic
Trans-Amazonian orogeny. The volcano-sedimentary unit was intruded by a post-tectonic quartz monzodiorite-diorite-hornblendite
stock. Initial Nd isotope ratios for the Omai volcanic rocks range from ɛNd=+2.1 to +4.2. These values suggest that this part of the Guiana Shield was a site of new crust formation during the Paleoproterozoic
and was not contaminated by older (Archean), reworked continental crust. Initial Nd isotope ratios for the Omai stock range
between +0.5 and +2.3, which suggest limited contamination with previously formed continental crust. Although the Nd isotopic
ratios of gold-related scheelites overlap with those of the host rocks, particularly the tholeiitic basalts at the interpreted
time of vein emplacement, the lack of both isotopic mixing and significant Nd movement during the hydrothermal process suggest
that the Nd isotope composition can be used to determine the isotopic characteristics of the ore fluid source area. At Omai,
the ore fluid is largely derived from a radiogenic Nd source, represented by mantle or lower crustal reservoirs. Strontium
isotope ratios for the scheelites cluster tightly between 0.7019 and 0.7021. The Sr isotope data suggest that unlike Nd, Sr
was significantly mobile during the hydrothermal process. The fluids responsible for the Omai deposit may have picked up Sr
along the flow path. The constant low Sr isotope values of scheelites probably reflect the key role that the local tholeiitic
basalts played as the main source of Sr in the fluids. Whereas Nd isotopes identify the fluid source area, the Sr isotopes
map the fluid flow paths.
Received: 11 February 1999 / Accepted: 1 November 1999 相似文献
16.
鲁西地区绿岩带金矿床铅同位素研究 总被引：2，自引：0，他引：2
在鲁西太古宙绿岩带中,分布有较多的绿岩带变生热液－构造蚀变岩型金矿,具有良好的找矿前景。从铅同位素组成来看,区内铅同位素变化较大,多为放射性成因铅质量分数较高的异常铅。所测同位素样品中,以黄铁矿铅同位素组成变化最大,是铅同位素在演化过程中受到放射性铀铅和钍铅不同程度混染的结果,多数样品单阶段模式年龄不具计时意义。计算表明,区内铅来源于ｕ＝９．２０,ｗ＝３７．４５,ｋ＝３．９５的源区,在５９５Ｍａ前 相似文献
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18.
文章选取金船塘锡铋矿床中的辉铋矿_黄铁矿矿石及长石样品进行了铅同位素分析 ,并对其中两个放射成因铅含量较高的黄铁矿进行了单矿物分步酸淋滤铅同位素分析。结果表明矿床的Pb_Pb等时线成矿年龄为(16 4± 12 )Ma,该年龄与千里山岩体燕山早期第一期的岩浆侵入年龄在误差范围内相同 ,说明矿化的发生与该期花岗岩的侵入关系非常密切。金船塘矿床铅同位素的构造演化模式研究表明铅来源于上地壳 ,说明千里山花岗岩体是由于上地壳发生部分熔融而形成的S型花岗岩 相似文献
19.
虎拉林矿床位于中亚造山带东段额尔古纳地块之上,处于上黑龙江盆地西侧,东与砂宝斯、老沟等金矿床相邻。矿床载金矿物主要为薄膜状、粒状及脉状黄铁矿,成矿与早白垩世花岗斑岩、石英斑岩及隐爆角砾岩有密切联系。在对矿床详尽的野外工作基础上,通过对金属硫化物硫、铅同位素分析研究,探讨成矿物质来源,揭示矿床成矿规律。研究结果表明,上黑龙江盆地虎拉林矿床矿石及围岩中黄铁矿δ34SV-CDT分布于0.7‰~2.2‰,平均为1.18‰,集中于1.0‰左右,呈塔式分布,显示主要为岩浆硫特征;铅同位素206Pb/204Pb、207Pb/204Pb、208Pb/204Pb值分别为18.468~18.511、15.578~15.625、38.215~38.370,分布范围较小,且具有造山带铅特征。铅同位素μ值为9.41~9.50,均小于9.58;ω值为35.04~35.93,均值35.49,小于正常铅ω值;Th/U为3.60~3.66,显示出具有壳幔混源特征;在铅同位素构造环境判别图中,显示出具有下地壳部分熔融的特征;Δγ-Δβ图解显示矿床铅来源于上地壳与地幔混合带俯冲岩浆作用成因的铅同位素源区。综合矿床类型、矿体产出特征、矿体及围岩硫、铅同位素特征认为,虎拉林金矿区成矿物质主要来源于下地壳物质熔融形成的深部岩浆,同时存在上地幔与上地壳部分熔融物质的参与,成矿过程与早白垩世岩浆活动关系密切,形成于蒙古—鄂霍茨克洋闭合后伸展环境背景下。 相似文献
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江西金山金矿床成矿物质来源的铅和硫同位素示踪 总被引：10，自引：3，他引：10
江西金山金矿床赋存于浅变质的中元古界双桥山群上亚群 ,该建造明显富Au ,Au平均丰度达 2 5 5× 10 -9。矿石铅同位素组成出现明显的线性关系表明 ,区域构造活动 成矿作用中存在着铅同位素的混合机制。大部分矿石铅Doe单阶段模式年龄与该矿床的Rb Sr年龄值十分接近 ,可能反映了区域变质的成矿意义。矿石铅 μ值介于 9 2 9～ 9 86之间 ,2 3 2 Th/ 2 3 8U比值变化于 3 88～ 4 0 9,揭示了成矿物质的壳源特征。Zartman图解和△γ △ β图解表明 ,双桥山群是矿石铅的主要源区。该矿床硫同位素组成特征与外围双桥山群上亚群中硫化物的硫同位素极为相似 ,成矿流体的硫主要来源于双桥山群含矿建造。对比研究表明 ,虽然不同金矿床的硫同位素组成特征不尽相同 ,但金山金矿床的层控特征与江南金成矿带中其他金矿极为相似。金山金矿床的铅、硫同位素地球化学特征揭示 ,该矿床的成矿物质主要来自浅变质的中元古界双桥山群含金建造 ,燕山期岩浆热液活动为该矿床的后期富集提供了部分成矿物质。 相似文献