江西省花山洞钨矿花岗岩锆石U Pb定年及其地质意义

花山洞钨矿是在江西省西北部新近发现的与花岗岩有关的钨矿床,为了确定矿区花岗岩的物质来源,形成过程以及构造背景环境,探讨成岩与成矿作用之间的关系。利用地球化学方法分析了与花山洞钨矿密切相关的花岗岩的地球化学特征,采用LA ICP MS锆石U Pb定年的方法测定了花岗岩的形成时代。岩石地球化学表明,花岗岩具有较高的w(SiO2)(6823%~7378%)含量;全碱含量w(Na2O+ K2O)为593%~7%;富Na,K2O/Na2O为038~086,小于1;w(Al2O3)为1441%~1581%,A/CNK均大于11,为过铝质岩石。富集Rb、Tu、U、La、Nd等大离子亲石元素,亏损Ba、Nb、Ti、Sr、P等元素,具大陆地壳的特征;稀土总含量较低,基本无δCe异常。稀土配分型式总体向右倾斜,为典型的‘I’型花岗岩特征;轻稀土斜率较大,分异较为明显,重稀土较为平缓,分异不明显。花岗岩锆石U Pb测年结果为(807±8)Ma,与前人测得的辉钼矿Re Os年龄极为接近,故花岗岩应该为成矿岩体。结合区域资料,综合分析可知,矿区花岗岩应主要来源于地壳物质,有部分地幔物质的加入;其可能形成于大陆边缘弧环境。花山洞钨矿床成矿年龄略晚于矿区花岗岩,表明成矿作用是花岗岩分异演化的结果,是晋宁期岩浆活动的产物。     

He–Ar Isotope Composition of Pyrite and Wolframite in the Tieshanlong Tungsten Deposit,Jiangxi, China: Implications for Fluid Evolution

The Tieshanlong tungsten‐polymetallic deposit is a large wolframite deposit of quartz vein type located in southern Jiangxi, South China. It is genetically related to a high‐K S‐type granite. Seven pyrite and two wolframite samples, selected for He and Ar isotope analyses, yielded ³He/⁴He values of 0.04–0.98 Ra, ⁴⁰Ar/³⁶Ar ratios of 293.5–368.0, and ³⁸Ar/³⁶Ar ratios of 0.176–0.193. These data indicate that the ore‐forming fluids associated with the deposit did not result from a simple mixing of the crustal‐ and mantle‐derived end‐member fluids, but that primeval meteoric fluids were also involved in the generation of the associated granitic magma by partial melting of crustal metasedimentary rocks. Further investigations show that only minimal He from the mantle was added during generation of the associated granitic magma. It is postulated that boiling and second mixing with “new” meteoric fluids took place during migration of magmatic‐hydrothermal fluids into wall‐rock fractures, resulting in a drastic decrease of their metal transport capacity, which triggered the tungsten‐polymetallic mineralization.     

江西岿美山钨矿矿床的成矿年龄及地质特征

江西省定南县岿美山钨矿区位于南岭东西向构造带东段与武夷山北东-北北东向构造带南段的复合部位,是赣南地区以石英脉型黑钨矿和矽卡岩型白钨矿共生为特征的钨矿床,其是否为南岭地区燕山期的成矿作用,一直没有精确的年代学研究成果。本文采用锆石SHRIMP U-Pb定年和辉钼矿Re-Os同位素定年技术,对岩体年龄和成矿年龄进行了精细的测定,获得成矿黑云母花岗岩体的锆石SHRIMP U-Pb年龄为（157.7±2.7） Ma（n=11,MSWD=1.9）,黑钨矿石英脉的辉钼矿Re-Os等时线年龄为（153.7±1.5） Ma（n=5,MSWD=0.16）,显示岿美山区是华南地区中生代钨矿大规模成岩成矿作用的产物之一。根据“五层楼+地下室”的找矿模型,并结合矿区的最新找矿线索,研究认为在矿区深部岩体的内外接触带具有存在新矿体的可能性,该区深部具有较大的找矿潜力,同时探索性地提出赣南地区石英脉型钨矿深边部存在矽卡岩型钨矿化的可能,对区域钨矿的深边部找矿工作具有指导意义。     

赣南樟东坑钨矿成矿花岗岩及矿化特征

[摘 要]樟东坑钨矿为崇-余-犹地区典型的花岗岩外接触带石英脉型钨钼矿床之一,矿区隐伏花岗岩分主体与"火焰状"脉体两种岩相产出,都与钨钼矿化有关,为成矿母岩。矿区花岗岩岩石化学总体特征:富硅、铝,贫铁、镁,钙中等,高碱、富钾,分异指数DI 较高,ACNK值以>1 为主,为酸性_超酸性、分异程度较高的钙碱性_碱性岩系,准铝质_过铝质壳源岩石重熔改造型花岗岩;其地球化学特征:微量元素富Rb、Th、U、K、Ta、Y 等低场强元素,而贫Ba、Nb、Sr、P、Ti 等高场强元素,稀土元素总量较低、略富轻稀土,Eu 严重亏损,稀土配分曲线呈“海鸥型冶,进一步显现壳型花岗岩特征,且岩浆演化程度较高。矿区钨钼矿化分为石英脉型和岩体型两类,受花岗岩侵入与分异演化控制,具有"上钨下钼"、"上脉下体"的矿化特征。樟东坑火焰状蚀变细粒花岗岩脉型钨钼矿化为赣南崇-余-犹脉钨矿区近年发现的新矿化类型,在赣南具有较大的找矿前景。     

赣南淘锡坑钨矿的石英中子活化分析研究

对赣南淘锡坑矿区V11号王牌矿脉不同中段的石英进行了中子活化分析,发现W主要与Sm、Lu、Yb、Mn、Sc、Ta、Fe等元素相关性比较好。在矿体的纵投影面上,识别出156中段和106中段各有3个浓集中心,并有从地表往深部W含量逐渐升高的趋势,显示矿液由南东往北西富集。预测枫林坑深部找矿前景较好。尝试性地进行了矿脉深部储量的预测研究,获得了 106m和56m两个中段的储量共10275.6t,加上156中段—356中段,合计V11号脉体的储量为19851.93t,与探明储量接近。可见,利用石英中子活化分析资料,有助于矿体深部储量的估算。     

Geology,Geochemistry, and Geochronology of the Fenghuangshan Skarn‐type Copper Deposit in the Tongling Ore Cluster,Anhui Province,East China

The Fenghuangshan skarn-type Cu deposit, Tongling Ore Cluster, Anhui Province, is an important component in the Middle–Lower Yangtze River ore-forming belt. To better understand magmatism and its relationship to mineralization, we investigated geochemical features, ore-forming fluids, and geochronology of the Xinwuli intrusion and the related Fenghuangshan Cu deposit. Lithogeochemical characteristics show that the Xinwuli quartz monzodiorite is formed by mixing magma derived from upper mantle alkaline basalt that has been contaminated by crust materials. C, H and O isotopes indicate that ore-forming fluids mainly come from the magma, with minor amounts of meteoric fluids involved at the late stage. S and Pb isotopic components indicate that ore-forming materials are derived from the mantle. Molybdenite Re–Os isotopic dating yields Re–Os model ages ranging from 139.1±2.4 Ma to 142.0±2.2 Ma, with an isochronal age of 141.1±1.4 Ma, which is consistent with sensitive, high-resolution ion microprobe (SHRIMP) zircon U–Pb ages of quartz monzodiorite and granodiorite in the mining area. Dating analysis yields ages from 136.0±2.0 Ma to 143.0±2.4 Ma for the quartz monzodiorite (a weighted average of 139.4±1.2 Ma) and ages from 136.7±2.0 Ma to 145.3±2.4 Ma for granodiorite (a weighted average of 141.0±1.1 Ma).     

赣南九龙脑岩体及洪水寨云英岩型钨矿年代学

通过赣南大余县九龙脑岩体及与之有密切成因关系的洪水寨云英岩型钨矿野外地质调查和系统的岩石化学、微量元素、稀土元素和成岩成矿时代研究,结合区域成岩成矿时代的最新研究成果,探讨了赣南地区钨矿的成岩成矿时代及构造环境。结果表明：九龙脑花岗岩体在化学成分上具有高Si、富碱、准铝质到弱过铝质、贫Ca、贫Mg、铁镁比值大、K₂O/Na₂O>1的特征;微量元素以富含Rb、K,亏损Ba、Sr等大离子亲石元素（LILE）和富含Th、U、Ce、Y、Sm、Nd、Ta、Hf,亏损Nb、P等高场强元素（HFSE）为主要特征,具强烈的Eu负异常（δEu=0.07～0.10）和较高的10 000Ga/Al特征比值（2.76~2.93）,所有这些均显示铝质A型花岗岩的特征。利用锆石SHRIMP U-Pb法,获得九龙脑岩体的成岩年龄为（155.8±1.2）Ma（n=12,MSWD=0.6）;利用辉钼矿Re-Os法,获得洪水寨云英岩型钨矿的成矿年龄为（156.3±1.3）Ma（n=7,MSWD=1.5）,成岩成矿年龄基本一致。结合崇(义)-(大)余-(上)犹钨锡矿集区已有的年代学资料,指出本区的成岩成矿年龄主要集中在150～160 Ma,属于华南中生代第二次大规模成矿作用,形成于中生代岩石圈伸展时期的侏罗纪板内拉张环境的地球动力学背景。     

赣南矽卡岩型钨矿成岩成矿年代学及地质意义——以焦里和宝山矿床为例

矽卡岩型钨矿是赣南地区的一种重要钨矿床类型。本文以焦里和宝山两个典型的矽卡岩型钨多金属矿床为例,开展了系统的成岩成矿年代学和岩石地球化学研究,结合区域钨锡矿床最新年代学研究成果,探讨了赣南地区钨矿的成岩成矿时代及形成构造环境。结果表明,焦里矽卡岩型钨多金属矿区斑状花岗闪长岩SHRIMP锆石U-Pb年龄为164.4±1.1Ma,辉钼矿Re-Os等时线年龄为170.6±4.6Ma;宝山矽卡岩型钨矿区花岗岩SHRIMP锆石U-Pb年龄为156.6±3.9Ma,辉钼矿Re-Os模式年龄加权平均值为161.0±1.9Ma,厘定了它们的成岩成矿年龄为中-晚侏罗世,同一矿区的成岩和成矿年龄在误差范围内基本一致。结合赣南崇(义)-(大)余-(上)犹钨锡矿集区已有的年代学资料,指出本区的成岩成矿年龄介于170～150Ma,集中在160～150Ma,认为赣南钨矿形成于华南中生代岩石圈伸展-减薄时期的侏罗纪板内拉张的地球动力学背景,系同一成岩成矿系统的产物。     

福建连城铜坑钼矿床辉钼矿Re-Os同位素年龄及燕山期成矿事件

福建连城铜坑钼矿床是近年来在闽西南地区找到的又一处钼矿床。钼矿化在铜坑燕山晚期第一阶段花岗斑岩岩体与晚古生界变质岩接触带内呈浸染状、脉状、透镜状等形态产出。本次研究过程中, 对6件代表性辉钼矿样品进行了Re-Os同位素年龄测定, Re-Os同位素模式年龄值为115.1~116.7 Ma, 等时线年龄为(115.7±1.1) Ma, 由此认为铜坑钼矿床与花岗斑岩的形成时间均为早白垩世, 属燕山晚期构造-岩浆活动的产物。结合矿区外围其他钼矿床同位素年龄数据可以推测, 闽西南坳陷燕山早期大规模钼矿化发生在印支期稳定的台地向活动大陆边缘转变阶段并伴随燕山早期挤压隆升(160~145 Ma), 燕山晚期由挤压向拉张机制转换(125~105 Ma)的构造改造阶段所诱发的岩浆活动是导致钼矿床形成的主导因素。     

赣南漂塘钨矿锡石及共生石英中流体包裹体研究

漂塘钨矿床是赣南地区一大型石英脉型钨多金属矿床,钨锡共生是该矿床的重要特征.在详细的岩相学观察基础上,采用“流体包裹体组合”(FIA)的研究方法,对该矿床锡矿化显著的(绿柱石)、锡石、黑钨矿-石英脉阶段石英脉中锡石及与其共生的石英中流体包裹体进行了显微测温和拉曼探针的分析.结果表明,锡石与共生石英形成的物理化学条件并不一致,两类矿物中流体包裹体揭示的流体演化过程也明显不同.锡石中原生的流体包裹体反映了锡石形成时真实的温压条件,与锡矿化相关的流体为高温、中-低盐度的NaCl-H2O流体体系.研究认为,锡石中流体可能主要来自于岩浆的结晶分异,流体体系的冷却是锡在流体中沉淀的主要机制.     

赣南大吉山花岗岩成岩与钨矿成矿年龄的研究

大吉山是赣南著名的钨—铌钽矿床,多年以来,由于受测试技术的限制,对该矿床的成矿年龄以及与成矿有关的大吉山花岗岩的成岩年龄缺乏系统和精确的研究。本文利用单颗粒锆石U-Pb同位素方法对大吉山补体花岗岩(铌—钽矿体的母岩)进行了成岩年龄测定,获得其侵位年龄为151.7±1.6Ma;利用快中子活化法对大吉山钨矿主矿脉中的云母进行了40Ar/39Ar地质年龄测定,获得了大吉山钨矿主矿脉的成矿年龄为144Ma和147Ma。根据这套数据,结合钨矿主矿脉、铌钽矿化和大吉山主体、补体花岗岩的空间产状,对它们的形成顺序进行了讨论。大吉山的花岗岩成岩与钨矿成矿年龄数据表明,它们是华南燕山中期陆壳重熔型花岗岩岩浆活动及相关的中生代第二次大规模成矿作用的产物。     

赣中良山钼矿床流体包裹体特征及其地质意义

良山钼矿是近年来赣中地区新发现的钼矿,浅部矿体主要赋存于南华系浅变质岩系的构造裂隙中,矿石类型以含辉钼矿石英脉为主。流体包裹体岩相学和显微测温结果表明：含辉钼矿石英脉中的流体包裹体主要呈星散状随机或成群分布,其形态多样,大小集中在2~15 μm,包裹体的类型主要有纯液相包裹体、富气相两相包裹体、富液相两相包裹体和含液体CO₂三相包裹体4类,其中以富液相两相包裹体最为发育;包裹体的均一温度为136~298 ℃,盐度为1.22%~10.11%NaCleqv,密度为0.78~0.99 g/cm3,成矿流体属中-低温、低盐度、较低密度流体;成矿压力估算为13~70 MPa,形成深度为0.5~2.6 km。流体包裹体激光拉曼光谱分析表明：包裹体中气液相成分以H₂O为主,气相中还有少量的CO₂和CO。H、O、S同位素组成显示：成矿流体的δD值介于-61‰~-57.9‰,δ¹⁸OH₂O值介于-3.32‰~-0.52‰,具有岩浆水和大气降水混合的特征;成矿热液中的δ³⁴S值介于-1.8‰~+1.9‰,具有岩浆硫的特征。综合成矿地质特征及相关分析,认为成矿流体可能与燕山期的岩浆活动有关,属于岩浆热液流体,混合作用及钾化作用是促进金属富集沉淀成矿的主要因素,推测矿床属于岩浆热液充填石英脉型钼矿。     

赣南铁山垅钨矿田花岗斑岩地球化学特征、锆石U- Pb年龄及Hf同位素特征

赣南铁山垅钨矿田位于南岭钨锡多金属成矿带东段,已探获黑钨矿资源量超10万吨。铁山垅复式岩体包括主体似斑状黑云母花岗岩和补体细粒二云母花岗岩两部分,花岗斑岩呈脉状分布。矿田内花岗岩具有相似的地球化学特征,都属过铝质高钾钙碱性花岗岩类,表现出高硅、富铝、富碱、高钾、富成矿元素（W、Sn、Cu、Mo）和亏损Ba、Sr、Ti、P、REE、Eu,稀土配分曲线呈典型的“海鸥式”分布和M型四分组效应等特征。利用LA- ICP- MS锆石U- Pb定年方法获得花岗斑岩206Pb/238U 年龄为146. 7±0. 5 Ma（MSDW=0. 5）,成岩时代属晚侏罗世。锆石的n(176Lu)/n(177Hf)=0. 000973～0. 001989,fLu/Hf=-0. 97～-0. 94,εHf(t)=-17. 9～-10. 3,二阶段模式年龄（TDM2）为1. 86～2. 33 Ga,显示原岩为古元古代地壳。综合分析认为,铁山垅矿田岩浆活动可划分为170～155 Ma、155～150 Ma、150～145 Ma三个阶段,钨锡矿成矿主要集中在第二阶段,且第三阶段花岗斑岩与铜多金属矿成矿关系密切,推测铜岭矿区深部具有较大的找矿前景。     

Geological Characteristics and Ore‐forming Time of the Dexing Porphyry Copper Ore Mine in Jiangxi Province

The Dexing porphyry copper ore mine is located in the Qin-Hang metallogenic belt between the Yangtze block and the Cathaysia block. It is a giant porphyry copper mine in China, including 3 ore districts: Tongchang, Fujiawu and Zhushahong. Our analyses of Re in molybdenite indicate that the ore-forming material of the copper ore deposits in Dexing should be mainly mantle-derived. Our study fills in a gap in the study of formation time of the Dexing copper mine, and further proves that the copper ore deposits in the three ore districts should be formed simultaneously, about 170 Ma, belonging to the early Yanshan period, and that the formation time of the copper ore deposits should be consistent with the formation time of granodiorite porphyry in which the copper ore deposits are hosted. Promising areas for seeking porphyry copper ore deposits is predicated to be the west or southwest of Dexing.     

江西东坪石英脉型黑钨矿矿床地质特征、控矿因素及找矿标志

东坪钨矿床是近年在赣北地区新发现的首个超大型石英脉型黑钨矿矿床,位于长江中下游成矿带幕阜山地区东坪-香炉山钨矿找矿远景区东部。矿床赋矿层位为新元古代双桥山群安乐林组浅变质岩系,北东向断裂及其两侧的次级裂隙为区内主要控矿构造、容矿构造,隐伏的燕山晚期黑云母二长花岗岩为成矿岩体,与区内钨多金属成矿关系密切的为石英脉状硅化;两个矿带的钨矿体均产于成矿岩体外接触带,呈现了石英脉型黑钨矿矿床典型的"五层楼"分带特征,矿石工业类型主要为黑钨矿矿石;明确了构造和岩浆岩等主要控矿因素;总结出地表微细裂隙云英岩化-黄铁矿化蚀变带、含硫化物石英细脉带、石英脉、重砂及地球化学异常为区内主要找矿标志。     

赣南西华山钨矿床成矿流体演化特征

赣南西华山钨矿床是一个闻名中外的大型石英脉型钨矿床。为探讨成矿流体性质以及演化过程,本文对西华山石英脉型钨矿床主成矿阶段含矿石英脉中流体包裹体进行了岩相学、显微测温学研究和激光拉曼光谱分析。结果显示,西华山钨矿床的流体包裹体以H2O-NaCl型为主,局部发育H2O-NaCl-CO2型。流体热焓-盐度图解表明成矿流体以混合作用为主,局部沸腾在热液系统演化中作用不大。通过对沸腾包裹体的测温数据进行计算,得出西华山脉型钨矿成矿压力约为27～87 MPa,矿床形成深度约为1.0～3.3 km。     

LA‐ICP‐MS Zircon U‐Pb Dating of Intermediate‐Acidic Intrusive Rocks and Molybdenite Re‐Os Dating from the Bangpu Mo (Cu) Deposit,Tibet and its Geological Implication

The multi-stage intrusions of intermediate-acid magma occur in the Bangpu mining district, the petrogenic ages of which have been identified. The times and sequences of their emplacement have been collated and stipulated in detail in this paper by using the laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) zircon U-Pb dating method. The ages of biotite monzogranite that were formed before mineralization in the southwest of this mining district are 70±1?Ma (mean square of weighted deviates (MSWD) =9.5, n=8) and 60.60±0.31?Ma (MSWD=3.8, n=16), which belong to the late Cretaceous–early Paleocene in age. That means, they are products of an early tectonic-magmatic event of the collision between the Indian and Asian continentals. The ages of ore-bearing monzogranite porphyry and ore-bearing diorite porphyrite are 16.23±0.19?Ma (MSWD=2.0, n=26) and 15.16±0.09?Ma (MSWD=3.9, n=5) separately, which belong to the middle Miocene in age; namely, they are products of the Gangdese post-collision extensional stage when crust-mantle materials melted and mixed as well as magmatic intrusion simultaneously occurred. Some zircons with ages of 203.6±2.2?Ma (MSWD=1.18, n=7) were captured in the ore-bearing diorite porphyrite, which shows that there had been tectono-magmatic events in the late Triassic–early Jurassic. Molybdenum (copper) ore-bodies produced in the monzogranite porphyry and copper (molybdenum) ore-bodies produced in the diorite porphyrite are the main ore types in this ore deposit. The model ages of Re-Os isotopic dating for the 11 molybdenite are 13.97–15.84?Ma, while isochron ages are 14.09±0.49?Ma (MSWD=26). The isochron ages of seven molybdenite from molybdenum (copper) ore with monzogranite porphyry type are 14.11±0.31?Ma (MSWD=5.2). There is great error in the isochron ages of four molybdenite from copper (molybdenum) ore with diorite porphyrite type, and their weighted average model ages of 14.6±1.2?Ma (MSWD=41), which generally represent the mineralization age. The results about the Re-Os isotopic dating of molybdenite in the ore of different types have limited exactly that, the minerlazation age of this ore deposits is about 14.09?Ma, which belongs to the middle Miocene mineralization. The Bangpu deposit has a uniform metallogenic dynamics background with the porphyry type and skarn-type deposits such as Jiama, Qulong and others.     

江西浒坑钨矿含矿石英脉的地质特征及成矿构造演化

位于赣西武功山地区的江西浒坑钨矿是一个大型石英脉型钨矿床,与赣南典型的“五层楼”模式不同,矿脉主要集中在岩体内接触带。含矿石英脉除了普通的块状构造以外,还普遍存在条带状构造。详细的野外编录和镜下研究表明含矿块状石英脉在形成后遭受不同程度的韧性剪切,从而形成不同成分的分异条带。剪切带以出现新生的面理和线理（拉伸线理）为特征。岩石学研究表明条带状矿石属于糜棱岩,具有丰富的塑性变形显微构造特征。通过对含矿石英脉的构造解析,认为与岩浆岩有关的原生节理系统基本上是同时形成的,沿节理充填的石英脉经历了长期的、多期次的构造运动,从而形成了复杂的石英脉和矿石类型。建立了原生节理形成→石英充填→韧性剪切发生→二期石英充填→脆性碎裂的矿区构造演化序列。韧性剪切作用的动力学背景可能是受后期岩浆侵入的影响,最后的脆性破裂应与区域上存在南北向的压应力有关。     

松潘－甘孜南部玛孜措石英闪长岩的地球 化学特征、同位素年龄及其构造意义

玛孜措石英闪长岩体位于松潘 甘孜地体南部的甘孜地体内,地处鲜水河断裂带西南侧。岩体具高钾（3.53%~3.86%）、富钙（4.91%~6.07%）、贫铝（14.60%~15.24%）,铝饱和指数（A/CNK=0.80~0.89）偏低的特征,岩石稀土总量较低,轻稀土中度富集,δEu介于0.46~0.53之间,Eu中度亏损,岩石（87Sr/86Sr）i比值介于0.707407~0.707640,表明岩浆起源于壳 幔混熔或下地壳物质的部分熔融,属下地壳重熔的I型高钾钙碱性花岗岩系列。在微量元素构造环境判别图上,样品都落在岛弧区,反映了石英闪长岩具有与岛弧型花岗岩相似的地球化学性质。岩体具较高的Rb（60.1×10-6~85.9×10-6）、Cs（4.01×10-6~19.62×10-6）含量和K2O/Na2O比值（1.31~1.82）,反映源区可能与黑云母的脱水熔融有关。玛孜措石英闪长岩锆石SHRIMP U Pb年龄为221±2.0 Ma（MSWD=1.4）,显示岩体侵位时代为晚三叠世;而全岩Rb Sr等时线年龄为207.0±2.0 Ma（R=0.9979）,显示岩体就位时代为晚三叠世晚期。玛孜措岩体形成于晚三叠世弧后构造环境,是幔源岩浆的底侵作用导致壳-幔混熔的产物。     

吉林四方甸子钼矿床成岩成矿时代及岩石地球化学特征

吉林四方甸子钼矿床是一新发现的石英脉型钼矿床,矿床产于二长花岗岩中。矿床成矿包括无矿石英脉阶段、石英-辉钼矿-黄铁矿阶段和石英-碳酸盐化阶段。通过对矿区内花岗质岩石进行LA-ICP-MS同位素测年,获得花岗闪长岩成岩年龄为（170.0±1.0） Ma,二长花岗岩成岩年龄为（179.0±1.0） Ma。对含矿石英脉中辉钼矿Re-Os同位素测年分析,获得辉钼矿模式年龄值为（175.0 ± 2.6）～（176.5 ± 2.6）  Ma,加权平均值为（176.1 ± 1.1） Ma,等时线年龄为（176.6 ± 4.2）  Ma,表明四方甸子钼矿床形成于早侏罗世晚期。岩体w(SiO₂)为66.17%～76.60%,w(Na₂O)和w(K₂O)分别为3.15%～5.40%和2.42%～5.42%,里特曼指数σ为2.17～2.93。稀土元素分布形式呈右倾型,轻、重稀土元素分馏明显。微量元素总体显示相对富集Rb、Ba、Th、U等大离子亲石元素（LILE）,亏损Nb、Ta、Ti、P等高场强元素（HFSE）。综合分析表明,岩石为弱过铝质I型花岗岩。成岩成矿动力学背景为燕山早期古太平洋板块向欧亚大陆俯冲作用的大陆边缘环境。