Excursion to Cambridge,April 10th and 11th, 1871     

T.G. Bonney  Harry G. Seeley 《Proceedings of the Geologists' Association. Geologists' Association》1872,2(5):219-226

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青藏高原东缘—扬子特提斯构造域深部结构与地壳形变研究     

王志  王剑  付修根 《地质论评》2021,67(1):1-12

青藏高原东缘和扬子西缘的构造带是中国特提斯构造域的重要组成部分,该构造域受欧亚板块与印度板块陆—陆碰撞、高原隆升、块体裂解或拼接挤压等强烈构造活动的影响,记录和保存了多期次的特提斯构造演化历史痕迹。同时,该研究区域也是中国西部地区地壳形变最强烈的地区之一,其浅表形变特征与深部构造之间存在怎样的关联和制约机制是目前国际地球科学的一个研究热点。本研究依据作者十多年来持续在该区域开展的地质—地球物理研究,通过深部地球物理多参数结构成像、沉积盆地分析、地壳形变和强震孕育机制等综合对比分析,发现在青藏高原东缘的下地壳存在低速和高泊松比异常带,该异常体与来自青藏高原上涌的软流圈热物质汇聚,导致从扬子西缘到青藏高原的下地壳和上地幔的深部结构发生显著变化。沿着龙门山断裂带,中、下地壳存在交叠相间的低速(高泊松比)和高速(低泊松比)区域,这些深部结构分布特征与地表形变及前陆盆地隆坳格局具有较好的一致性。基于上述认识,提出了青藏高原东缘—扬子板块的深部接触模式及其相应的盆山耦合关系,阐明了板块碰撞—耦合的深部动力学过程对剧烈地壳形变、盆地隆坳格局和强震诱发的制约关系。本研究成果将为深入认识青藏高原东缘高原急剧隆升、盆地基底结构与隆拗格局,以及强烈地壳形变的深部动力学机制提供参考信息。  相似文献   

云县邦东—景谷民乐地区火山岩型铜矿找矿前景   总被引：1，自引：0，他引：1  

段继云  李石英  杨文军 《云南地质》2010,29(2):128-131

本区位于滇西特提斯沟—弧—盆构造体系的主火山弧地体中,处于澜沧江褶断束东凸弧形转折处,上三叠统小定西组钙碱性火山碎屑岩、次火山岩含矿,火山机构控制矿体的产出形态,后期构造、侵入体使矿体叠加、富积,矿化类型为火山—次火山岩热液改造矿床;地、物、化、遥等成矿地质条件有利,具有很好的找矿前景。  相似文献   

鸡西群城子河组时代的进一步探讨   总被引：9，自引：1，他引：9  

姜宝玉  冯金宝 《地层学杂志》2001,25(3):217-221,240

近年来 ,古生物工作者在鸡西群城子河组及其相当地层的生物化石研究方面取得了巨大的进展。在总结这些新的材料的基础上 ,通过与国外的化石组合进行对比 ,从海相双壳类、植物、孢粉及海相沟鞭藻化石等多方面的证据 ,尤其是根据 Thracia rotundata、Vectianella、Pseudaphrodina ricordeana等欧洲 Aptian阶重要的双壳类化石、被子植物及三沟类被子植物花粉的出现 ,城子河组的时代应为 Aptian期 - Albian期早期  相似文献   

古深断裂活化与燕山期陆内造山运动——以川南—滇东和中扬子褶皱-冲断系为例   总被引：18，自引：1，他引：18  

吴根耀 《大地构造与成矿学》2001,25(3):246-253

基于花岗岩侵入、构造变形和磨拉石建造(或长期隆起)提出川南—滇东和中扬子地区侏罗-白垩纪时发生造山事件。分析了造山带的内部结构、范围和动力机制,发现川南—滇东褶皱-冲断系为北东向及近南北向断裂控制发育,其西以滇中古陆块与燕山期消减型造山带相隔;中扬子褶皱-冲断系为北西向断裂控制发育,向南西扩展时止于黄陵古陆核。两者均属印支运动后出现的中国—东南亚次大陆外侧的新特提斯洋消减,及嗣后的碰撞激活拼合大陆内的古深断裂活化而发生的燕山期陆内造山运动,构成中国大地构造演化的一个显著特色。  相似文献   

Radio Properties of BL Lac Object S5 2007+777     

《Chinese Astronomy and Astrophysics》2019,43(4):519-538

S5 2007+777 is a typical BL Lac object with a low peak frequency, and a kpc-scale extended X-ray jet. In the literature, the Doppler factor derived at the X-ray waveband by means of model estimation is about 13.0, then the intrinsic jet scale can reach the order of magnitude of 1 Mpc. In this work, we have studied the radio structure of the jet, the brightness temperature, proper motion and other properties of this source with the collected EVN (European VLBI Network) high-resolution archive data, and the American VLBA (Very Long Baseline Array) 15 GHz observed data, etc. It is found that the jet directions measured at the different wavebands of the VLBI (Very Long Baseline Interferometry) are consistent, but slightly different from the direction of the kpc-scale X-ray jet given by the literature and the direction of the VLA (Very Large Array) radio jet, which means that the Doppler brightening effect exists in the jet emission of the source. Both the mean value and median value of the radio Doppler factor of this source estimated from the brightness temperature that measured by the VLBI are 5.0, which is smaller than the Doppler factor at the X-ray waveband given by the literature, but consistent with the Doppler factor at the radio waveband obtained by using the other methods in the literature. Furthermore, by fitting the data observed in multiple epochs, it is found that the various components of the source at the same waveband do not have an evident proper motion in a long epoch, but the proper motion in short epochs exhibits even a super-luminal motion. This may be caused by the transfer of the central position of the component with a low surface brightness. Meanwhile, this also verifies the conclusion that the radio Doppler factor estimated previously is not very large, and smaller than the Doppler factor in the X-ray waveband. By using the obtained radio Doppler factor, it is found that the source has an intrinsic radio jet of rather large scale, which may reach 0.5 Mpc, because the mean value is adopted in this case, thus it indicates that the source also possibly possesses a jet close to the scale of a giant radio galaxy.  相似文献   

Reliability Analysis of Main-axis Control System of the Antarctic Equatorial Astronomical Telescope Based on Fault Tree     

L.I. Yun  Yang Shi-hai 《Chinese Astronomy and Astrophysics》2018,42(3):448-461

The Antarctic astronomical telescopes work chronically on the top of the unattended South Pole, and they have only one chance to maintain every year. Due to the complexity of the optical, mechanical, and electrical systems, the telescopes are hard to be maintained and need versatile expedition teams, which means that an excessive awareness is essential for the reliability of the Antarctic telescopes. Based on the fault mechanism and fault mode of the main-axis control system for the Antarctic equatorial astronomical telescope AST3-3 (Antarctic Schmidt Telescope 3-3), the method of fault tree analysis is introduced in this article, and we obtain the importance degree of the top event from the importance degree of the bottom event structure. From the above result, the hidden problems and weak links of the system can be effectively found out, which will indicate the direction for improving the stability of the system and optimizing the design of the system.  相似文献   

吉林省五凤-五星山金矿床地质特征与成矿条件     

冯守忠 《地质与资源》1994,3(4):241-247

五凤一五星山金矿床属中生代陆相火山岩浅成热液型金矿床。侏罗系上统金沟岭组火山岩为其主要矿源层,矿体受火山机构的断裂、裂隙和次火山岩脉内外接触带的控制。碱长花岗岩侵入金沟岭组底部位,为金矿形成提供了主要热源。成矿作用主要进行于低压、中性介质和弱氧比、超浅成条件下。金矿一般富集于如下部位,即矿体上部;矿体转弯、膨大处及分支复合处;强冰长石绢云母硅化蚀变岩中;含细粒黄铁矿的方解石石英脉;辉银矿集中地段。  相似文献   

川滇地区地震活动与地球自转速率变化之间的关系     

陈学忠  李艳娥 《地震》2019,39(1):126-135

利用川滇地区1962—2016年间发生的MS≥6.0地震资料,在去除余震的情况下,分析了其发生与地球自转速率变化极值点之间的关系。得到以下结果:川滇地区MS≥6.0地震的发生与地球自转速率变化极值点具有显著关系,对于不同震级范围的地震,其与不同周期的地球自转速率变化有关。对于MS≥7.0的地震,有90%发生在地球自转速率季节性变化极值点前14天至后37天时间段内;对于6.0≤MS≤6.4的地震,有80%发生在地球自转速率短周期变化极值点前68小时至后30小时的时间段内;对于6.5≤MS≤6.9的地震,有87.5%发生在地球自转速率短周期变化极值点前36小时至后64小时的时间段内。地震发生在特定时间段的显著性检验结果表明,川滇地区MS≥6.0地震与地球自转速率变化极值点的关系都可以在α=0.05的显著性水平下通过显著性检验。这个结果表明,在地球自转速率发生转折的期间容易触发地震,对川滇地区地震发生时间预测具有参考意义。  相似文献   

安丘—莒县断裂小店—大店段断层活动证据及断层泥分布特征初步研究     

付俊东  王志才  熊仁伟  王雷  张广成  夏暖 《地震》2017,37(2):57-66

郯庐断裂带最新活动的断层分布于潍坊至嘉山一带, 而安丘—莒县断裂是郯庐断裂带的重要活动断裂之一。 基于地质考察、 高密度电法探测和钻孔联合剖面, 对安丘—莒县断裂小店—大店段断层活动证据及断层泥分布特征进行研究。 地质考察发现紫红色砂砾岩逆冲到全新世耕植土上方, 两者之间发育断层泥带, 断层泥内含少量角砾岩, 为全新世活动逆断层。 高密度电法探测结果表明断层通过位置电阻率差异明显。 钻孔联合剖面揭露的地层: 全新世耕植土、 全风化砂质泥岩、 强风化砂质泥岩、 碎裂岩、 断层泥带及中风化砂质泥岩。 钻孔K1和K2揭露深灰色断层泥带, 倾向西, 倾角约为74°, 厚度约为13.9 m, 与南侧出露的断层泥带产状相协调。 工作区范围内, 发育多处褶皱、 破碎带和断层泥带, 断层表现为全新世逆断层性质。  相似文献