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1.
《矿物岩石地球化学通报》2015,(6)
为探讨山西铜矿峪铜矿床绿泥石的成岩成矿意义,运用电子探针分析了矿床中斑岩型铜矿中的绿泥石。结果显示,矿区绿泥石可以分为与石英硫化物脉共(伴)生的绿泥石(Ⅰ型)、与方解石硫化物脉共(伴)生的绿泥石(Ⅱ型)、斑岩中的绿泥石(Ⅲ型)和围岩蚀变带中的绿泥石(Ⅳ型)4种类型。4种类型绿泥石主要为富铁种属的蠕绿泥石(铁绿泥石)和密绿泥石,指示其均形成于偏还原环境;在其结构的离子置换中均表现为Fe对Mg的置换,反映其形成都与铁镁质围岩有关,并都经历了多期次变质作用。由绿泥石地质温度计估算出4类绿泥石的形成温度为180~220℃,均属于中-低温热液蚀变范围。在铜成矿过程中,随着温度不断下降热液流体性质向酸性逐渐演化。 相似文献
2.
西藏斯弄多银多金属矿床产于陆相林子宗群火山岩内,是冈底斯成矿带发现的首例浅成低温热液矿床.矿床具有热液脉型银铅锌矿体、隐爆角砾岩型矿体和独立银矿体"三位一体"的矿体组合形式.热液角砾岩作为矿区主要矿(化)体,目前尚未开展详细研究工作.文章以斯弄多矿区热液角砾岩为研究对象,通过钻孔岩芯编录和岩相学研究,总结了不同类型热液角砾岩特征,旨在探讨其成因及与成矿的关系.根据热液角砾岩产状、颜色、胶结物等特征,将矿区热液角砾岩分为气喷角砾岩、岩浆蒸汽角砾岩和构造热液角砾岩三类.岩浆蒸汽角砾岩产于隐爆角砾岩筒中,根据其产状、颜色、胶结物成分差异进一步分为A类角砾岩和B类角砾岩.A类角砾岩产于Ⅰ号富矿角砾岩筒,蚀变矿物以绢云母、蒙脱石、伊利石为主;B类角砾岩产于Ⅱ号贫矿角砾岩筒,蚀变矿物以白云母、赤铁矿、黄钾铁矾为主.研究认为,与成矿作用密切相关的热液角砾岩成岩成矿作用是同一地质过程不同阶段的产物,其含矿性主要由隐爆流体性质决定.大气降水和岩浆热液不同程度的混合作用和沸腾作用是角砾岩形成和矿质沉淀的主要原因. 相似文献
3.
新疆塔吾尔别克金矿位于著名的阿希金矿附近,矿床产于下石炭统大哈拉军山组第5段安山岩及安山质凝灰岩中,矿床主要受NW—NNW向构造蚀变带的控制,同时次火山相二长斑岩、爆破角砾岩筒(隐爆角砾岩)对成矿也具控制作用;蚀变类型主要有黄铁绢英岩化、硅化、碳酸盐化,热液成矿期包括石英-黄铁矿、石英-硫化物和石英-碳酸盐等3个阶段,形成蚀变岩型、石英脉型和石英-碳酸盐脉型3种金矿化类型,表生期形成氧化金矿。在阐述矿床地质特征基础上,归纳出构造控矿规律、火山-次火山岩体控矿规律、中-低温成矿规律和多因复合成矿规律,综合勘查和研究成果,认为矿床的成因类型为与晚古生代早-中期火山热液有关、有次火山(斑岩型、爆破角砾岩筒型和隐爆角砾岩型)热液成矿作用叠加的浅成低温热液型金矿床。 相似文献
4.
内蒙古阿鲁科尔沁旗好力宝铜钼矿床地质特征及找矿方向 总被引：5，自引：1，他引：4
好力宝铜钼矿床属与燕山期隐伏的隐爆角砾状斜长花岗斑岩和碎裂次石英斑岩有关的热液脉状和斑岩型矿床.铜钼矿体受隐爆角砾岩筒和岩体控制,矿化产在蚀变隐爆角砾岩和硅化带中.今后的找矿方向应侧重于对斜长花岗斑岩与围岩接触带和碎裂次石英斑岩中化探异常和低阻高极化异常地段的探索. 相似文献
5.
金厂铜金矿床是中国东北的一个特大型矿床,大地构造位置处于兴蒙造山带东缘,成矿时代集中于110～ 130Ma.金厂铜金矿床矿体类型主要为角砾岩型和裂控型.角砾岩型矿(化)体以J-1矿体为代表,产于穷棒子沟Ⅰ号角砾岩筒内,为典型的隐爆角砾岩筒,全筒矿化,与围岩界限清楚.矿区内角砾岩型矿体常成群成串出现,东西走向具等间距分布特征.裂控型矿体包括环形和放射状矿体,环形矿体以Ⅱ和18号脉群为代表,放射状矿体以Ⅲ脉群为代表.Ⅱ脉群处于裂控型矿体的上部,18号脉群处于Ⅱ脉群的下部,矿体呈层状或脉状分布,在剖面上具“背形”分布特征,环形矿体由内向外存在矿化分带现象.金厂铜金矿床产于太平洋板块俯冲产生的陆缘弧环境,其流体性质及成矿物质来源均与深部岩浆岩有关,角砾岩型矿体和裂控型矿体均具有斑岩型矿床的成矿特征. 相似文献
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内蒙古西乌旗白音查干矿床是大兴安岭南段锡矿带内最典型、规模最大的Sn-Ag-Zn-Pb矿床。电气石在成矿岩体花岗斑岩和围岩地层中均广泛发育，依据其产状可分为四类：Ⅰ团斑状电气石；Ⅱ热液角砾岩胶结物中电气石；Ⅲ热液脉状电气石；Ⅳ弥散状电气石。在详细的岩相学基础上，利用电子探针点分析和面扫描分析对不同产状和结构的电气石进行了详细的成分分析。结果显示，花岗斑岩体深部的团斑状电气石（Ⅰa类）以自形、环带发育为特征，至少可见三期生长环带：核部电气石（Ⅰa-1）极高的Fe/（Fe+Mg）和Al值暗示其岩浆成因；边部电气石（Ⅰa-3）较富Mg，且与热液矿物共生，是从早期热液流体中沉淀形成的；幔部电气石（Ⅰa-2）的结构和成分显示其形成可能与不混溶的富B-Fe-Na的熔体或流体有关。因此，电气石从核部到边部的生长记录了从晚期岩浆到早期热液阶段的演变过程。花岗斑岩体中上部的团斑状电气石（Ⅰb类）环带不发育，其与热液矿物共生的组合及成分暗示其形成更倾向于与热液过程相关，可能是岩浆顶部聚集的早期流体释放之后被固结岩浆"圈闭"的残余流体结晶的产物。随后，大规模释放的富B流体形成了大量以电气石为主要胶结物的热液角砾岩（Ⅱ类）、成矿前电气石-石英阶段脉系（Ⅲa类）及伴随围岩蚀变而形成的弥散状电气石（Ⅳ类）。对Ⅱ类和Ⅲa类电气石内存在的生长环带分析显示，成矿前可能存在多个脉冲期次且成分有差异的流体的叠加作用。同时，电气石从早期到晚期向富Mg方向的演化，及成分明显受围岩地层影响的现象，暗示岩浆热液流体与围岩地层发生的水岩反应可能在金属成矿过程中起了重要作用。此外，本研究显示，不同产状电气石的结构和成分信息能够有效记录矿床内岩浆-热液转变及热液演化过程的众多细节信息，为深入理解成矿过程提供了依据。 相似文献
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《地球化学》2016,(6)
红海VMS铜锌矿床位于新疆东天山大南湖-头苏泉岛弧带的卡拉塔格地区,矿床上部发育似层状块状硫化物矿体,下部为不整合的脉状-网脉状矿体,块状矿体上盘火山岩盖层中也发育少量铜矿化。本文在前人工作基础上,根据矿物交代次序、脉体穿插关系和矿物共生组合类型,精细划分了矿床的蚀变分带和成矿期次。矿床(含盖层)从浅到深依次发育绿泥石-钠长石-绢云母-碳酸盐化、绿帘石-绿泥石-钠长石-绢云母-碳酸盐化、石英-绢云母-黄铁矿化、块状硫化物矿体、绿泥石-黄铁矿±绢云母化和绿泥石-石英-绢云母化。红海矿床成矿过程可分为VMS成矿期、后期热液叠加期和表生期,其中VMS成矿期可细分为黄铁矿阶段、黄铜矿-闪锌矿阶段和重晶石阶段,后期热液叠加期可细分为钠长石化阶段、绿泥石-绿帘石阶段和石英-碳酸盐阶段。主矿化期及蚀变特征与典型VMS矿床类似,但同时还表现出许多海底交代作用的特征。后期热液在矿体上盘火山岩中所产生的绿帘石化、绿泥石化和绿帘石-石英-黄铜矿-斑铜矿脉、石英-碳酸盐脉等蚀变和矿化,与斑岩矿化系统的青磐岩化类似,表明红海矿床后期可能受到斑岩系统的叠加,矿区具有斑岩铜矿床的找矿潜力。 相似文献
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江西永平铜矿区花岗岩热液蚀变与岩石成因:矿物化学、元素地球化学和Sr-Nd-Hf同位素制约 总被引：15，自引：11，他引：4
永平铜矿床是位于华南钱塘江-信江断裂坳陷带中的一个大型铜矿床.矿区内出露的岩浆岩主要有似斑状黑云母花岗岩体和少量石英斑岩脉,黑云母花岗岩岩体内及接触带发育斑岩型和矽卡岩型铜钼钨多金属矿化.对岩体中黑云母的电子探针成分分析表明,似斑状黑云母花岗岩中黑云母具有富镁贫铁高钛的特点,Fe/(Fe Mg)为0.21～0.33,TiO2含量为2.12%～4.28%;而石英斑岩脉中黑云母更加富镁贫铁,Fe/(Fe MS)为0.10～0.15,TiO2含量为2.43%～3.86%.黑云母的化学组成表明花岗质岩浆形成时的氧逸度很高,与长江中下游地区其他含铜花岗质岩体相吻合.永平花岗岩体遭受了较强的热液蚀变作用,部分黑云母蚀变为绿泥石.石英斑岩中绿泥石具有富铁贫镁低钛的特征(Fe/(Fe Mg)=0.72～0.76;TiO2=0.02%～0.06%),其形成温度为139～224℃.而似斑状黑云母花岗岩中绿泥石相对贫铁富镁高钛(Fe/(Fe Mg)=0.36～0.44;TiO2=0.05%～0.36%),形成温度稍高,为229～346℃,与该矿床流体包裹体研究获得的成矿温度(220～400℃)基本吻合.Sr-Nd-Hf同位素综合研究表明,永平似斑状黑云母花岗岩具有变化较大且相对较高的εHf(t)值(-0.1～-10.3)和εNd(t)值(-5.83～-7.95),反映岩石具有明显的壳幔混合成因特征.而石英斑岩的εHf(t)值(-8.4～-12.5)和εNd(t)值(-9.93～-10.2)均稍低于似斑状黑云母花岗岩,反映其形成过程中幔源物质贡献相对较小.永平岩体的地壳端元很可能就是该区中元古代基底地层重熔的产物. 相似文献
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英德尖峰山黄铁矿普查区初步确定为沉积-热液叠加改造型黄铁矿床。矿床受地层、构造、岩相古地理环境等因素控制。根据矿区Ⅰ、Ⅱ、Ⅲ号矿体与地层、构造的相关关系预测：矿区Ⅱ号矿体规模最大，Ⅰ、Ⅲ号矿体规模偏小；矿区南部F1断层与下古生界地层、花岗岩体(或花岗闪长岩体)交汇处是寻找硫化物伴生金矿、石英脉型岩金矿的远景区段。 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
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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.
Muriel Rocher Stéphane Baize Stéphane Jaillet Edward Marc Cushing Yannick Lozac&#x;h Francis Lemeille 《Comptes Rendus Geoscience》2003,335(8):701-708
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003). 相似文献
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正20141756 Chen Ruige(Mathematical College,China University of Geosciences,Beijing100083,China);Zhou Xun Numerical Simulation of Groundwater Level Fluctuation in a Coastal Confined Aquifer with Sloping Initial Groundwater Level Induced by the Tide(Geological Bulletin of China,ISSN1671-2552,CN11-4648/P,32(7),2013,p.1099-1104,6 illus.,16 refs.) Key words:confined water,groundwater level 相似文献
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正20141408 Cai Jia(Institute of Geology,Chinese Academy of Geological Sciences,Beijing100037,China);Liu Fulai Petrogenesis and Metamorphic P-T Conditions of Garnet-Spinel-Biotitebearing Paragneiss in Danangou Area,Daqingshan-Wulashan Metamorphic Complex Belt(Acta Petrologica Sinica,ISSN1000-0569,CN11-1922/P,29(7), 相似文献
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正20142386An Guoying(China Aero Geophysical Survey and Remote Sensing Center for Land and Resources,Beijing 100083,China)Application of Satellite Remote Sensing in Regional Hydrogeological Investigation:Taking Cenozoic Strata in Wenquan Sheet(1∶250 000)of Karakoram Range as an Example(Geosci- 相似文献
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正20141016An Chengbang(Key Laboratory of Western China’s Environmental Systems,Ministry of Education,Lanzhou University,Lanzhou 730000,China);Zhao Yongtao Lake Records during the Last Glacial Maximum from Xinjiang,NW China and Their Climatic Impli- 相似文献
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正20141538 Cao Qing(School of Earth Sciences and Engineering,Xi’an Petroleum University,Xi’an 710065,China);Zhao Jingzhou Characteristics and Significance of Fluid Inclusions from Majiagou Formation,Yichuan Huangling Area,Ordos Basin(Advances in Earth Science,ISSN1001-8166,CN62-1091/P,28(7),2013,p.819-828,7 illus.,3 tables,43 refs.) 相似文献