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新疆东天山康古尔剪切带西段金矿床的成矿流体特征及其地质意义 总被引：2，自引：2，他引：0
东天山觉罗塔格地区沿着康古尔韧性剪切带发育众多金矿床,已经成为新疆重要的黄金产地之一。文章对位于该剪切带西段储量较大、勘查程度较高的红石、康古尔和马头滩3个金矿床进行了地质特征、流体包裹体和氢氧同位素研究,结果表明,这3个矿床含矿石英脉流体包裹体的均一温度分别为294.4~468.0℃(红石)、236.9~441.0℃(康古尔)、150.9~444.7℃(马头滩);盐度w(NaCleq)分别2.7%~10.5%(红石)、4.2%~9.1%(康古尔)和6.4%~8.4%(马头滩);密度分别为0.54~0.83 g/cm3(红石)、0.80~0.86 g/cm3(康古尔)和0.57~0.80 g/cm3(马头滩)。本文和前人数据表明,这3个矿床的δDSMOW值分别为-104‰~-63‰(红石)、-72‰~-45‰(康古尔)和-55‰~-45‰(马头滩),与石英相平衡的水的δ18OH2O值分别为-1.7‰~7.4‰(红石)、-8.3‰~5.0‰(康古尔)和2.5‰~2.6‰(马头滩)。以上特征表明,红石、康古尔和马头滩金矿床成矿流体具有中-高温、低盐度、较高CO2含量,其中红石金矿床的成矿流体中岩浆水比例比康古尔和马头滩两个矿床相对要高。综合地质、流体和年代学特征表明,沿康古尔韧性剪切带分布的金矿床可能具有较为一致的成因,可能是295~280 Ma和260~240Ma两个成矿期叠加作用的产物,分别与早二叠世拉张背景下的中-酸性岩浆的侵入和晚二叠世—早三叠世(260~240 Ma)挤压背景下康古尔剪切带的韧性剪切变形及抬升作用相对应。 相似文献
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条形山金矿位于康古尔-黄山韧性剪切带北缘,该剪切带变形特征显著,与康古尔塔格金矿带、金矿床关系密切。该带呈近EW向波状延伸,总体向南微凸,长600 km,宽2~10km,带内及两侧已发现哈尔拉、石英滩、麻黄沟、康古尔、马头滩、元宝山等多个金矿。 相似文献
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东天山康古尔金矿床的同位素地球化学特征及成因讨论 总被引：1，自引：0，他引：1
主要研究了康古尔金矿的流体包裹体的氢,氧同位素组成以及硫,铅和碳同位素组成,结果表明该２金矿床主矿化阶段成矿流体以变质为主,晚期以大气降水为主,总的表现为下部上升流体与浅部大气降水混合成矿特征。该矿床的成矿物质具深源性,主要来自上地幔或下部地壳,是一种火山岩区剪切带蚀变型岩金矿床。 相似文献
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中亚造山带在显生宙期间经历了强烈的陆壳增生与改造作用,其地壳增生过程和成矿作用复杂多样。晚古生代的天山以大规模走滑剪切变形、同构造岩浆和多金属成矿作用为显著特征,是中亚造山带增生汇聚作用的典型地区。前人的研究主要关注于剪切带起源与演化时限、变形特征或独立矿床的典例剖析,缺乏针对剪切带演化与成矿时空联系的综合研究。本文选取天山康古尔-黄山剪切带出露的代表性矿床——康古尔金矿和红山南金矿,开展金矿石中绢云母^(40)Ar/^(39)Ar定年研究,并结合前人报道的年代学数据来探讨金成矿与大规模剪切活动的时空联系,从而揭示区域差异性隆升与成矿作用的耦合关系。定年结果显示,康古尔金矿的成矿时代为264.8±1.7Ma,而红山南金矿的成矿时代为261.5±1.5Ma,与康古尔-黄山剪切带右行走滑运动时间(约279~249Ma)一致。基于康古尔-黄山剪切带西段和东段在区域地质、动力学背景、岩浆作用时间、右行走滑运动的相似性和矿床空间分布的差异性,本文认为康古尔-黄山剪切带中西段的岩浆镍铜硫化物矿床和(中成至深成)造山型金矿床可能尚未出露,深部找矿潜力大,而东段出露深度大,岩浆铜岩浆镍铜硫化物矿床分布广,但中-浅成造山带金矿剥蚀殆尽,深部潜力不足。综合区域构造演化历史,本文认为康古尔-黄山剪切带的东-西差异是天山-北山三叠纪斜向汇聚所引起的区域差异性隆升导致,而差异性隆升则是区域内现今构造变形和矿床空间分布分布巨大差异的主要原因。 相似文献
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新疆东天山剪切带型金矿床时代研究 总被引：23，自引：5，他引：23
东天山造山带中部的秋格明塔什-黄山巨型韧性剪切带内三个典型的剪切带型金矿床——康古尔金矿床、红石金矿床和红山金矿床的同位素年代学研究表明,金矿床成矿作用和剪切带后期的走滑剪切变形作用在时间上具有强烈的耦合关系。秋格明塔什-黄山韧性剪切带剪切变形作用主活动期的时代为262.9～242.8Ma,而剪切带型金矿床金成矿作用发生在261.0～246.5Ma 之间,恰好落在剪切变形作用主活动期的时代范围之内。这种强烈的耦合关系证明了秋格明塔什-黄山韧性剪切带晚期的右行走滑剪切变形作用才是剪切带内一系列金矿床成矿作用的主因。金成矿和右行走滑剪切变形之间的时间耦合关系在不同部位还有不同的表现。在剪切带中-西段的康古尔地区,快速抬升发生在261.5～262.9Ma,而康古尔金矿床主成矿期时代范围是261.0～252.5Ma,可以看出,康古尔金矿床成矿作用刚好发生于剪切带中-西段快速抬升之后。在剪切带东段,快速抬升发生在247.1～246.9Ma 期间,位于该剪切带东段北外带的红山金矿床主成矿期的年龄范围是246.9～246.5Ma,表明该金矿也是在剪切带东段快速抬升冷却之后形成的。金矿石 Ar-Ar 同位素年代学研究未能得到可靠的和早期韧性推覆剪切变形事件相对应的年龄,推测在晚石炭世—早二叠世发生的韧性推覆剪切变形事件可能仅导致了包括金在内的金属元素的初步富集,但由于高温不利于金属元素沉淀和挤压环境不易存在容矿空间等不利因素的影响,导致此阶段并没有形成有工业开采价值的金矿床。只是到了华力西晚期—印支早期,在原韧性推覆剪切带内发生了走滑剪切变形活动,并产生了快速抬升冷却降温到350℃后,在地体缓慢冷却阶段,在脆-韧性剪切带内才有足够的空间和时间形成金矿床。 相似文献
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康古尔塔格金矿带位于塔里木和准噶尔两大板块的碰撞活动地带，EW长200km，有金矿床(点)二十多处。矿床主要产于下石炭统阿奇山组中酸性火山岩中，具层控性，各类岩石Au平均含量高出地壳克拉克值的3—11倍。华力西中晚期—印支早期中酸性浅成相侵入岩类与金成矿关系密切。沿康古尔塔格和苦水断裂发育一系列平行韧性剪切带，是金矿床产出的主要部位。金矿带具水平分带和垂直分带性，金矿脉呈带呈群分布，成矿具有阶段性，矿床类型主要为蚀变岩型和石英脉型，成因属中浅成中低温热液型矿床。 相似文献
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康古尔韧脆性剪切活动控制着东天山二叠纪大规模的金成矿作用。新发现的石东金矿位于东天山康古尔韧性剪切带西段,赋存于石炭系凝灰质砂岩与石炭纪正长斑岩接触带。根据该矿床矿物共生组合和蚀变类型成矿过程可分为黄铁矿-绢云母-石英阶段(Ⅰ)、石英-多金属-自然金阶段(Ⅱ)和绿泥石-方解石-石英阶段(Ⅲ),主成矿阶段(Ⅱ)以粗大石英硫化物脉、中温热液蚀变为特征。载金硫化物及自然金电子探针数据显示该矿床与中低温变质热液活动关系密切,认为是二叠纪康古尔韧性剪切活动过程中形成的金矿床。石东正长斑岩(平均K2O=8.8%)富集大离子亲石元素且具有较低的Mg#值(平均为30.8),认为其起源于康古尔增生杂岩部分熔融,与石东金矿没有直接成因联系。康古尔剪切带内地层-岩浆-构造活动均对二叠纪大规模金成矿事件有贡献,石炭纪碱性花岗侵入体与二叠纪脆-韧性变形是重要找矿标志。 相似文献
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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
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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
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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