地壳波浪运动机制探讨     

何安明  石焕文 《地球科学与环境学报》2002,24(3):41-43

讨论了地壳波浪运动形成的机制及其效应 ,并为地壳波浪状镶嵌构造学说提供了初步的数理模型和理论依据。  相似文献   

三峡库区巴东马鬃山地振动观测与成因讨论   总被引：8，自引：7，他引：1  

李峰  薛军蓉  韩晓光 《大地测量与地球动力学》2004,24(2):78-82

在长江三峡巴东库段马鬃山村开展地振动现场仪器监测和宏观调查的基础上，着重对其形成条件及成因机理进行了分析。初步认为，该村近半年来持续发生的地振动、地声及民宅破坏等地质灾害，部分来自近邻构造地震的影响，而大多数是溶洞塌陷引发的非构造地震。  相似文献   

Effective relaxation time and viscosity of the earth inferred from the postseismic vertical deformations of the 1990 MS=7.0 Gonghe earthquake   总被引：2，自引：0，他引：2  

王庆良  巩守文  张希  祝意青 《地震学报(英文版)》1997,(5)

Ｅｆｅｃｔｉｖｅｒｅｌａｘａｔｉｏｎｔｉｍｅａｎｄｖｉｓｃｏｓｉｔｙｏｆｔｈｅｅａｒｔｈｉｎｆｅｒｅｄｆｒｏｍｔｈｅｐｏｓｔｓｅｉｓｍｉｃｖｅｒｔｉｃａｌｄｅｆｏｒｍａｔｉｏｎｓｏｆｔｈｅ１９９０ＭＳ＝７．０ＧｏｎｇｈｅｅａｒｔｈｑｕａｋｅＱＩ...  相似文献   

Neutrino Geophysics Conference Introduction     

John G. Learned  Stephen T. Dye  Sandip Pakvasa 《Earth, Moon, and Planets》2006,99(1-4):1-15

Long distance detection of electron anti-neutrinos from reactors at distances of order 200 km has been achieved with the 1000 ton liquid scintillator-based KamLAND instrument in Japan. In summer 2005 the KamLAND group reported the first detection of anti-neutrinos from the natural radioactivity of the earth. These measurements are due to uranium and thorium decays dominantly from the nearby crust in Japan, and are expected to have only a small contribution from the earth’s mantle (and core). Several new detectors are under consideration around the world for measurements which when taken together can reveal the location of these heavy elements, which are expected to contribute a major share of the internal earth’s heating via their radioactivity. This heating is of course associated with providing the power to drive the geomagnetic field and plate tectonics. Geologists have only indirect evidence about the deep earth, mostly from seismic wave velocity and inferences from a few meteorites. Anti-neutrino detection, on the other hand, yields direct information about earth’s interior. The location and magnitude of the earth’s uranium and thorium are crucial to understanding the origin and evolution of the earth and present day activity. Lead Article in Proceedings of Neutrino Sciences 2005  相似文献   

空间碎片天基光电光学可见条件与预报   总被引：1，自引：0，他引：1  

桑思武  许尤楠  刘艳华  叶小宝 《天文研究与技术》2006,3(3):271-274

随着航天活动的增加，产生的空间碎片也越来越多，空间环境日趋恶化，已经对人类的空间活动构成了威胁。监视测量这些空间碎片，天基光电比地基光电更为有利，而天基光电的光学可见条件与地基光电相比，有相似的，也有不同的，针对天基光电，给出了空间碎片的光学可见条件，即日光条件、地影条件、地光条件、地球背景条件、月光条件。在天基光电轨道特征、光学可见条件及天基光电坐标系已知的情况下，建立起天基光电预报方法。既可用于空间碎片预报，也可以用于空间碎片的轨道识别。  相似文献   

数字化形变观测干扰识别   总被引：18，自引：4，他引：14  

王梅  李峰  孔向阳  刘厚明 《大地测量与地球动力学》2004,24(1):94-98

收集整理了山东省数字化形变台自观测以来的固体潮分钟值资料，论述了气压、雷电、洞室进入、仪器故障及附加载荷等干扰因素对数字化形变高频记录的影响及其机理，为利用数字化资料及时识别干扰、准确捕捉短临地震异常提供了可借鉴的实例。  相似文献   

多坐标系中心组合图在地球信息图谱化中的应用     

李仁杰  张军海  傅学庆  谷宝庆 《测绘科学》2007,32(3):49-51

本文用典型实例验证了斜角坐标系量化图形中的多坐标系中心组合图展现地球信息图谱的优势和特点。这类图形以其“多坐标系”的特点和多种多样的组合形式,能够承载更大量的信息、更易反应数据内在规律。通过选择最佳的图形类型,对地球信息进行高效传输,通过图形使宏观的地学自然规律变得清晰可见,提供地学信息图谱的一种新展现手法。  相似文献   

Rare earth element geochemistry of the Woxi W–Sb–Au deposit, Hunan Province, South China     

Xuexiang Gu  Oskar Schulz  Franz Vavtar  Jianming Liu  Minghua Zheng  Shaohong Fu 《Ore Geology Reviews》2007,31(1-4):319

The Woxi W–Sb–Au deposit in Hunan, South China, is hosted by Proterozoic metasedimentary rocks, a turbiditic sequence of slightly metamorphosed (greenschist facies), gray-green and purplish red graywacke, siltstone, sandy slate, and slate. The mineralization occurs predominantly (> 70%) as stratabound/stratiform ore layers and subordinately as stringer stockworks. The former consists of rhythmically interbedded, banded to finely laminated stibnite, scheelite, quartz, pyrite and silty clays, whereas the latter occurs immediately beneath the stratabound ore layers and is characterized by numerous quartz + pyrite + gold + scheelite stringer veins or veinlets that are typically either subparallel or subvertical to the overlying stratabound ore layers. The deposit has been the subject of continued debate in regard to its genesis. Rare earth element geochemistry is used here to support a sedimentary exhalative (sedex) origin for the Woxi deposit. The REE signatures of the metasedimentary rocks and associated ores from the Woxi W–Sb–Au deposit remained unchanged during post-depositional processes and were mainly controlled by their provenance. The original ore-forming hydrothermal fluids, as demonstrated by fluid inclusions in quartz from the banded ores, are characterized by variable total REE concentrations (3.5 to 136 ppm), marked LREE enrichment (La_N/Yb_N = 28–248, ∑LREE/∑HREE = 16 to 34) and no significant Eu-anomalies (Eu/Eu = 0.83 to 1.18). They were most probably derived from evolved seawater that circulated in the clastic sediment pile and subsequently erupted on the seafloor. The bulk banded ores are enriched in HREE (La_N/Yb_N = 4.6–11.4, ∑LREE/∑HREE = 3 to 14) and slightly depleted in Eu (Eu/Eu = 0.63 to 1.14) relative to their parent fluids. This is interpreted as indicating the influence of seawater rather than a crystallographic control on REE content of the ores. Within a single ore layer, the degree of HREE enrichment tends to increase upward while the total REE concentrations decrease, reflecting greater influence and dilution of seawater. There is a broad similarity in chondrite-normalized REE patterns and the amount of REE fractionation of the banded ores in this study and exhalites from other sedex-type polymetallic ore deposits, suggesting a similar genesis for these deposits. This conclusion is in agreement with geologic evidence supporting a syngenetic (sedex) model for the Woxi deposit.  相似文献   

云南中基性火山岩风化壳离子吸附稀土成矿作用分析 ——以腾冲龙井山安山岩风化壳型稀土矿床为例     

曾招金  祝向平  张彬  高儒东 《地球学报》2021,42(6):936-944

近年来在云南发现了多个离子吸附型稀土矿,特别是滇西的腾冲—陇川地区、临沧—勐海地区成为了找矿突破最大、最受关注的地区.本次工作在腾冲火山岩带南部龙井山发现一套富含轻稀土的第四系中基性火山岩建造,该含矿建造稀土元素丰度平均值达532×10–6.经过系统的调查研究及采样工作,结果表明腾冲龙井山新近纪中的辉石安山岩富含轻稀土,为一种年轻火山岩形成的风化壳型稀土矿床,矿体平均厚度9.15 m,平均品位(TREEO)0.11％,矿体品位、厚度变化与风化壳厚度呈正相关.该中基性火山岩离子吸附型稀土矿床的发现丰富了云南稀土矿床类型.这种年轻的中基性火山岩型稀土矿的成矿地质背景、地球化学特征等,为寻找中基性岩有关的稀土矿床提供参考.  相似文献   

基于PCA-SVM算法对稀土元素与稀土判别指标耦合数据集的铀矿床分类     

刘云鹏  郭春影  秦明宽  吴玉  裴柳宁 《吉林大学学报(地球科学版)》2021,51(3):723-733

不同类型铀矿床的沥青铀矿/晶质铀矿具有不同的稀土元素组成,其组成可作为判别铀矿床类型的重要指标。采用基于Python语言的主成分分析（principal component analysis,PCA）与支持向量机（support vector machines,SVM）结合的分类模型,对收集到的全球已知6种类型铀矿床的216组沥青铀矿/晶质铀矿稀土元素数据进行研究。以216组数据为训练集,通过数据清洗、特征缩放、PCA特征提取、网格搜索和交叉验证参数寻优构建SVM分类模型,对24组同变质型胡家峪晶质铀矿进行智能识别。研究结果显示：仅使用稀土元素的14维训练集最优模型判定胡家峪晶质铀矿类型的测试准确率为0.4%;由稀土元素、稀土总量、轻重稀土比、铕异常组成的17维训练集最优模型的测试准确率为75.0%,较14维训练集提高74.6%,模型泛化能力强;而通过传统稀土元素配分曲线、w（ΣREE）-（LREE/HREE）_N图解不能有效判定胡家峪晶质铀矿类型。本次研究表明,PCA-SVM算法对增有传统稀土判别指标数据集进行挖掘可有效厘定铀氧化物成因类型,效果明显优于单纯的稀土元素数据集以及传统的稀土配分曲线、w（ΣREE）-（LREE/HREE）_N图解。  相似文献