共查询到20条相似文献，搜索用时 46 毫秒
1.
华北克拉通南北缘三叠纪钼矿化类型、特征及地球动力学背景 总被引：6，自引：1，他引：5
华北克拉通南北缘是中国最重要的钼成矿带,特别是近年来在南北缘陆续发现了大量的钼矿床,显示了巨大的钼资源前景。其中三叠纪钼矿床的不断发现引人注目。在华北克拉通北缘及邻区三叠纪钼矿床在空间上总体呈EW向展布,矿床产出受区域东西向断裂控制,钼矿床的形成与三叠纪酸性侵入体关系密切,多产于花岗岩体中、斑岩体内外接触带或附近,矿床类型包括斑岩型和石英脉型。在华北克拉通南缘及邻区,三叠纪钼矿床总体上呈NW向展布,受区域NW向断裂控制,钼矿床的形成与晚三叠世酸性侵入体及碳酸盐脉有关,矿床产于斑岩体内及附近,矿床类型包括斑岩型、石英脉型及碳酸盐脉型。成矿年代学研究表明,华北克拉通北缘及邻区三叠纪钼矿主要形成于248~220Ma,而南缘及邻区三叠纪钼矿床主要形成于226~210Ma。其对应的成矿动力学背景为印支期华北板块与西伯利亚板块同碰撞造山过程和扬子板块与华北板块同碰撞造山过程。 相似文献
2.
秦岭造山带秋树湾铜钼矿床辉钼矿Re-Os定年及其地质意义 总被引：33，自引：4，他引：33
秋树湾铜钼矿床是秦岭造山带东段最大的斑岩-夕卡岩型铜钼矿床,通过对矿石中6个辉钼矿样品的 Re-Os 同位素分析,得到了145.57±1.80～147.98±2.21Ma 的模式年龄(平均为146.42±1.77Ma)及一个相关性很好的等时线年龄147±4Ma,表明秋树湾铜钼矿床形成于晚侏罗世,与其以北的华北克拉通南缘的主要斑岩型钼矿床及位于扬子克拉通北缘的长江中下游铁铜矿床的大规模成矿时间一致,是中国东部中生代第2期大规模成矿作用的产物。秋树湾铜钼矿床辉钼矿的含铼量平均达151.8×10~(-6),明显高于华北克拉通南缘钼矿带同期形成的钼矿床(16.13×10~(-6)～28.09×10~(-6)),认为主要是由于两者成矿元素 Cu/Mo 比值的不同造成的;结合矿石硫同位素特征,认为矿床的物质主要来源于下地壳。 相似文献
3.
山西代县滩上钼多金属矿床位于华北陆台北缘五台山—恒山多金属成矿区,分布于滩上复式杂岩体与滹沱群四集庄组含砾变质长石石英岩的接触带及附近岩石裂隙中,其中辉钼矿呈细脉状、团块状、星点状。在对区内钼多金属矿床地质特征研究的基础上,选取7件辉钼矿样品进行Re-Os同位素测年。获得的模式年龄为(129.3±2.0)～(132.3±1.8)Ma,加权平均年龄为(131.09±0.98)Ma,MSWD=1.2,等时线年龄为(131.60±0.72)Ma,MSWD=1.08,187Os初始比值为(-0.041±0.036)ng/g。该等时线年龄代表了辉钼矿的形成时间,可以作为该矿床的形成年龄,即钼成矿作用发生于早白垩世。与华北陆台北缘五台山-恒山多金属成矿区内多个矿床一样,该矿床推测是燕山期大规模构造-岩浆-流体活动的产物,与中生代以来华北克拉通减薄事件有关。 相似文献
4.
5.
内蒙古化德县三胜钨钼矿床位于华北陆块北缘,为岩浆期后中高温热液型矿床。采用辉钼矿Re-Os同位素分析获得辉钼矿的模式年龄加权平均值为138±1Ma,等时线年龄为138.6±1.4Ma,推测三胜钨钼矿床的形成时代为燕山晚期,这与区域上华北陆块北缘主要金属矿床的形成年龄吻合。辉钼矿的Re含量平均值为0.5548×10~(-6),表明其主要为地壳来源特征。成矿发生在陆内构造环境,为燕山期大规模构造-岩浆作用的产物。 相似文献
6.
《铀矿地质》2021,(5)
红山子铀钼矿床位于华北陆块北缘的沽源-红山子铀多金属成矿带和西拉沐沦钼多金属成矿带上,该矿床内发现有发育在花岗斑岩内的辉钼矿化。通过对辉钼矿进行Re-Os同位素测定,获得模式年龄为(137.2±3.2) Ma和(138.2±2.1) Ma,对围岩花岗斑岩锆石进行SHRIMP U-Pb同位素测定,获得成岩年龄为(133.1±1.2) Ma。两种方法获得的年龄相近,表明成矿和成岩大致同时形成,均属早白垩世。另辉钼矿的Re含量为(186.6～216.8)×10~(-6),表明该钼矿化的成矿物质来自于地幔。通过与西拉沐沦钼多金属成矿带的典型矿床开展综合分析,认为红山子铀钼矿床的发育在花岗斑岩内的钼矿化具有斑岩型钼矿化特征,且应属该成矿带的138 Ma成矿期,该矿化是在白垩纪华北克拉通岩石圈减薄的大地构造背景下,由地幔组分与岩石圈作用形成的岩浆携带地幔含矿流体上侵而形成的钼矿化。 相似文献
7.
豫西银家沟硫铁多金属矿床Re-Os和40Ar-39Ar年龄及其地质意义 总被引：4，自引：1，他引：3
河南省银家沟硫铁多金属矿床位于华北克拉通南缘的华熊地块内,是东秦岭地区最大的硫铁多金属矿床,以其硫铁矿储量大及共、伴生元素复杂区别于东秦岭其他以钼为主的矿床.矿化在空间上呈规律性的带状分布,从岩体内向外,依次出现斑岩型钼矿体→斑岩型硫铁矿体→矽卡岩型铁矿体、钼矿体→矽卡岩型硫铁、铜、锌、金矿体→脉型铅、锌、银矿体.选取5件接触带矽卡岩型钼矿体中的辉钼矿样品进行Re-Os同位素定年,获得(142.9±2.1) Ma～(143.7±2.3) Ma的模式年龄,加权平均值为(143.4±0.9) Ma(MSWD=0.071),等时线年龄为(140.0±18.0) Ma(2σ,MSWD=0.095),将(143.4±0.9) Ma认作辉钼矿的结晶年龄,表明银家沟矿床矽卡岩型矿体形成于约143 Ma前;选取1件硅化、绢云母化、黄铁矿化、辉钼矿化钾长花岗斑岩中的绢云母样品定年,获得40Ar-39Ar坪年龄为(143.6±1.4) Ma,相应的39 Ar/36 Ar-40 Ar/39Ar等时线年龄为(143.0±2.0) Ma(MSWD=0.13),将(143.0±2.0)Ma认作绢云母的Ar封闭年龄,表明银家沟矿床斑岩型矿化亦发生在约143Ma前.本次辉钼矿Re-Os和绢云母40Ar-39A定年结果表明,银家沟矽卡岩型和斑岩型矿体均形成于早白垩世初期.银家沟矿床辉钼矿的ω(Re)在38.5×10-6～43.2×10-6之间,成矿物质主要来自由火成物质组成的宽坪群和二郎坪群,成矿与矿区内的钾长花岗斑岩有关.结合前人对东秦岭造山带中生代期间地球动力学背景的研究成果,笔者认为银家沟矿床形成于EW向构造体制向NNE向构造体制大转换阶段,即形成于挤压体制向伸展体制转换的背景. 相似文献
8.
滇中老街子Pb-Ag多金属矿床的成矿时代及成矿动力学背景探讨：来自硫化物Re-Os同位素证据 总被引：3，自引：0，他引：3
滇中老街子Pb-Ag多金属矿床位于红河-哀牢山新生代富碱斑岩带的中段,是与富碱火山-岩浆热液密切相关的典型矿床。首次在该矿床深部发现70m宽的高Cu-Mo异常黄铁矿化蚀变正长斑岩和黄铁矿-辉钼矿矿脉(2073中段3#穿脉),认为该矿床深部存在明显的富碱斑岩-岩浆热液型铜-钼矿化叠加成矿作用。本文选取深部坑道内的辉钼矿-黄铁矿脉、黄铁矿-方铅矿脉和高Cu-Mo异常黄铁矿化蚀变正长斑岩进行辉钼矿-黄铁矿Re-Os同位素成矿年代研究,获得了辉钼矿Re-Os等时线年龄33.71±0.29Ma和加权平均值年龄33.99±0.22Ma,说明滇中老街子斑岩型铜-钼成矿作用时代为渐新世,与Cu-Mo异常黄铁矿化蚀变正长斑岩成岩年龄一致。黄铁矿的初始Os比值(0.3049~1.5549)及其γOs值(140.5~1126)指示老街子Pb-Ag多金属矿床金属成矿物质主要来源于壳幔相互作用而形成的岩浆。老街子Pb-Ag多金属矿床成岩成矿年龄和区域上富碱斑岩-岩浆热液型多金属矿床成岩成矿年龄(30~40Ma)大致相当,表明印度板块与欧亚板块碰撞期后,构造应力场发生转变形成大规模区域左行走滑断裂系统,在稳定块体内部诱发壳幔过渡层发生部分熔融形成富碱岩浆和成矿流体,成矿流体沿着构造薄弱部位形成富碱斑岩-岩浆热液型多金属矿床。 相似文献
9.
内蒙古西拉木伦铜-钼成矿带花岗岩特征与成矿专属性 总被引：1，自引：0，他引：1
近期在华北克拉通北缘中段西拉木伦断裂带两侧发现了多处与晚古生代-中生代花岗岩有关的铜-钼多金属矿床,如碾子沟钼矿、车户沟铜-钼矿、库里吐铜-钼矿、鸡冠山钼矿、小东沟钼矿等.成矿年龄分布在260～130 Ma之间,且成矿年龄与区域分布花岗岩年龄基本一致[1～4].至目前为止尚缺少对这一带铜钼矿床成因、构造背景以及形成规律的详细研究. 相似文献
10.
钦杭成矿带南段旗鼓岭铜钨钼多金属矿床的辉钼矿Re-Os同位素年龄及成矿物质来源 总被引：2，自引：0，他引：2
广东旗鼓岭铜钨钼多金属矿是近年来在云开地区新发现且具有重要找矿远景的矿床之一。矿体形态不规则,主要呈层状、似层状和透镜状产出在矽卡岩中。本文在详细了解矿床地质特征的基础上,通过辉钼矿Re-Os同位素定年技术首次对旗鼓岭矿床进行了成矿时代的厘定。5件辉钼矿样品的模式年龄为163.6~165.3Ma,加权平均年龄为164.54±0.94 Ma,表明旗鼓岭铜钨钼多金属矿床成矿作用发生于中侏罗世晚期。该矿床辉钼矿样品的Re含量变化于76.86~86.22μg/g之间,表明其成矿物质具有壳幔混源的特征。黄铁矿的δ~(34)S组成范围比较窄,变化范围为1.4‰~2.5‰,显示来自于岩浆热液。旗鼓岭铜钨钼多金属矿床成矿年龄的厘定为下一步在区内开展150~170 Ma左右的斑岩-矽卡岩多金属矿床找矿勘探提供了重要的线索,也标志着著名的钦杭成矿带进一步向南延伸,同时为进一步深入研究钦杭成矿带成岩成矿作用提供了新的资料和证据。 相似文献
11.
Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco. 相似文献
12.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
13.
The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species. 相似文献
14.
Emmanuel Skourtsos Daniel Vachard Alexandra Zambetakis-Lekkas Rossana Martini Louisette Zaninetti 《Comptes Rendus Geoscience》2002,334(12):925-931
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931. 相似文献
15.
16.
正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.) 相似文献
17.
正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.) 相似文献
18.
正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.) 相似文献
19.
正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus., 相似文献
20.
正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an 相似文献