桃林铅锌矿断裂变质带的地质特征研究

详细的野外观察和室内研究表明,桃林断裂变质带中存在有糜棱岩和碎裂岩两个系列的断裂变质岩,并具分带性,说明该带经历了韧性和脆性两个不同机制的变形阶段。笔者认为该断裂变质带早期为一韧性剪切带,晚期叠加了脆性断层。     

论构造分层、流变分层和化学分层作用——以中下扬子区倾滑断裂系统为例

为揭示中下扬子区地壳结构特征和构造与成矿的相关性，在区内全面探集岩石力学，岩石流变和岩石化学样品测试分析，划分出六磁层滑一倾滑区域性导位断裂系统。并以构造分层，流变分层和化学分层系统定量参数论述这些断裂中的分异分层或称变质分层作用。通常以流变分层作为变质分层研究的主体，构造分层为基础，化学分层则是研究的深入和继续。     

北塘凹陷断裂特征与油气分布规律

基底大断裂控制了北塘凹陷的构造格架，形成了各具特征的西部、北部和南部三大断裂系统．发育了7种成因特征的断裂，总结出6种断裂组合发育模式．基底大断裂(临近生油区的)及其次级断裂控制了油气的宏观分布，形成以断裂为主控因素的复式油气聚集区带．对油气生运聚散和分布有控制作用的控烃断裂有：控源断裂、油源断裂、遮挡断裂、改向断裂、控圈断裂和破坏断裂6种基本类型．断块是油气藏的基本单元，其周边断裂既是遮挡断裂又是控圈断裂．     

柴达木盆地断裂构造效应

柴达木盆地花状构造是在走滑挤压性断裂作用下，分别通过三种途径而形成：在走滑挤压性断裂的弯曲会聚区，由于岩层收敛挤压而产生；在两条或两条以上斜列的走滑挤压性断裂的重叠离散区，由于挤压及非共轴递进变形作用而形成；在底基断裂之上的沉积盖层中，由于底基断裂的走滑挤压作用派生出次级应力场作用而发展。花状构造组合为油气运移和储集提供了有利的地质条件。     

东营凹陷沙三-东营期断裂活动特征

断裂是控制东营凹陷构造演化的主要因素。应用断层落差法对东营凹陷沙河街-东营期的断裂活动特征进行了研究。结果表明，东营凹陷古近纪在近南北向的伸展方向上，断裂活动强弱交替，在沙三-沙二早期断层活动强烈，沙二晚期-东营期断层活动明显减弱。东营凹陷的断层在平面和剖面上有多种不同的几何形态，组成了半地堑、半地垒和地堑-地垒多种形式的断块体，其组合分布使整个凹陷具有南北分区块断的构造特征。断裂活动时空分布具有不均一性，在北西-南东向和南北向的双向伸展作用下，东营凹陷的断裂活动在空间上具有分段性特征。     

金属断裂表面分形特性初探

论述了近10余年来金属断裂表面分形维数的测量方法，以及分形维数与力学性能之间关系的研究成果和研究进展，综合分析了金属断面分维与金属的拉伸性能、冲击韧度、断裂韧度、材料损伤之间关系。讨论了金属断裂与分维的一些具体的内在矛盾和进一步改进的措施。     

铝合金宏观断裂准则

为研究铝合金抗断设防，借鉴金属静水应力型屈服概念，给出了铝合金广义屈服椭球面的新诠释．基于三向等拉伸应力状态下铝合金屈服和断裂的重合性假设，导出了铝合金在三轴应力空间的椭球面断裂准则及参数量化方法，并给出了铝合金抗断设防图及广义屈服椭球面的物理解释．该断裂准则使铝合金在三轴应力空间的屈服和断裂两种破坏模式得到了统一，具有物理概念清晰、形式简单、便于工程应用的特点．铝合金开孔板断裂试验的数值模拟结果显示，该断裂准则具有较高的精度．     

钢框架节点局部断裂冲击作用实验研究

对钢框架节点在强烈地震或极端荷载情况下因突然断裂引起的冲击作用进行了研究．讨论了断裂冲击值与断裂位置内力释放值的对应关系，通过单质点模型分析了冲击反应的量值范围，考察了冲击反应峰值与冲击作用时间和断裂发生后体系自振周期之比的关系．设计并实施了钢材单轴断裂和模型框架节点断裂两种实验，验证了采用具有高频采样能力的测试设备准确测取断裂过程中结构反应的可行性，揭示了节点瞬间断裂仍然包含渐进性和局部性两项特点．对节点瞬间断裂引起的冲击反应进行了初步的数值评估．     

定向断裂控制爆破理论与技术应用

基于定向断裂控制爆破技术参数的选取有别于普通光面爆破，研究了定向断裂控制爆破理论及应用成果.分析了定向断裂控制爆破理论聚能装药结构和装药外壳切缝爆破技术定向导向缝成缝机理，提出了炸药爆炸能量随爆炸动静作用变化分配观点，指出定向断裂控制爆破实质是对炸药爆炸能量在介质中的作用加以控制的问题，研究新型装药结构，提高炸药爆炸的能量利用率和定向断裂方向的爆炸能流是改善定向断裂控制爆破效果的主要研究方向。     

钢中近界面微区的形变与断裂Ⅰ-夹杂物与基体界面近区的形变与断裂

采用增量拉伸、表面复型及剖面金相技术，结合断口分析，揭示夹杂物与基体从相容形变残留内应力到不相容形变而发生夹杂物或其与基体界面断裂成孔洞，孔洞近邻基体局部形变断裂与孔洞长大聚合及最终断裂的微观过程．根据夹杂物特性，结合界面微观力学分析，闸明夹杂物近界面的形变断裂与钢宏观断裂的机理及夹杂物与钢力学性能关系．     

Petrology, geochemistry and geodynamics of basic granulite from the Altay area, North Xinjiang, China

The basic granulite of the Altay orogenic belt occurs as tectonic lens in the Devonian medium- to lower-grade metamorphic beds through fault contact. The Altay granulite (AG) is an amphibole plagioclase two-pyroxene granulite and is mainly composed of two pyroxenes, plagioclase, amphibole and biotite. Its melano-minerals are rich in Mg/(Mg Fe^2 ),and its amphibole and biotite are rich in TiO2. The AG is rich in Mg/(Mg Fe^2 ), Al2O3 and depletion of U, Th and Rbcontents. The AG has moderate ∑REE and LREE-enriched with weak positive Eu anomaly. The AG shows island-arc pattern with negative Nb, P and Ti anomalies, reflecting that formation of the AG may be associated with subduction. Geochemical and mineral composition data reflect that the protolith of the AG is calc-alkaline basalt and formed by granulite facies metamorphism having peak P-T conditions of 750℃-780℃ and 0.6-0.7 Gpa. The AG formation underwent two stages was suggested. In the early stage of oceanic crustal subduction, calc-alkaline basalt with island-arc environment underwent granulite facies metamorphism to form the AG in deep crust, and in the late stage, the AG was thrust into the upper crust.     

The geological characteristics of oceanic-type UHP metamorphic belts and their tectonic implications: Case studies from Southwest Tianshan and North Qaidam in NW China

The geological characteristics of ultrahigh-pressure （UHP） metamorphic belts formed by deep subduction of oceanic crust are summarized in this paper. Oceanic-type UHP metamorphic belt is characterized by its protolithlc assemblage of typical oceanic crust, the peak metamorphic temperature 〈600℃, P-T path undergoing blueschist facies during prograde and retrograde metamorphic evolution, reepectively, with low geothermal gradient of cold subduction. The further study of oceanic-type UHP metamorphic belt is very significant for constructing metamorphic reaction series of cold subduction zone, for understanding how aqueous fluids were transported into deep mantle and for classifying the types of UHP metamorphism in cold subduction zone. The uplift and exhumation mechanism of oceanic UHP metamorphic rocks is one of the most challenging problems in the study of UHP metamorphism, which is very important for understanding the geodynamic mechanism of solid Earth. As a traveler eubducted into the mantle depth end then uplifted to the surface, oceanic-type UHP metamorphic belts witness the bulk process from the subduction to exhumation and is an ideal target to study the geochemical behavior end cycling of elements in subduction zones. The tectonic evolution of one convergent orogenic belt can be usually divided into two stages of oceanic subduction and followed continental subduction and collision, and the two best-established examples of orogenic belts are Alpa and Himalaya. Therefore, the study of oceanic-type UHP metamorphic belt is the frontier of the current plate tectonic theory. As two case studies, the current status and existing problems of oceanic-type UHP metamorphic belts in Southwest Tianshan and North Qaidam, NW China, are reviewed in this paper.     

超高压变质作用及大陆深俯冲--地球科学前沿述评

目的总结和评述超高压变质及大陆深俯冲作用研究进展。方法文献阅读及专题研究。结果总结分析了超高压变质及大陆深俯冲作用的时空分布、俯冲深度极限、俯冲过程中流体的性状及作用,以及中国西部北秦岭、柴北缘和阿尔金超高压变质岩带的研究现状及特点。结论超高压变质岩石均形成于碰撞造山带中,时代以显生宙为主;大陆俯冲的深度有可能达到200 km以上的地幔深处;超高压变质过程中有流体的参与,但流体的活动局限在很小的范围内。     

采用时频滤波技术的近断层脉冲地震人工模拟

利用现代时频分析工具S变换的时频滤波特点,把反映场地局部特征的实际远场地震波或人工合成的远场地震波在等效速度脉冲的发生时间段实行时频滤波,再与等效速度脉冲叠加,生成既能反映场地局部特征又能反映近断层脉冲地震特点的人工近断层脉冲地震时程.通过数值算例,得到的人工近断层地震波与原始波有相似的时频特征,而功率谱密度函数在高频段与建筑抗震规范相容的目标功率谱一致,该波的峰值加速度还与抗震规范中相应烈度的峰值一致,可供近断层地区结构抗震分析使用.     

Finding of high-pressure mafic granulites in the Amdo basement,central Tibet

High-pressure mafic granulites with a peak mineral assemblage of garnet + clinopyroxene + rutile + quartz were found in the Amdo basement, central Tibet. Two kinds of symplectites were identified that are composed of orthopyroxene + plagioclase ± spinel and hornblende + plagioclase around garnet, which were interpreted to develop during the retrogressing stages in the granulites. P-T estimates suggested that peak metamorphic conditions were about 860–920°C and 1.46–1.56 GPa, which retrogressed from post-peak phase at 820–890°C and 0.88–1.15 GPa to amphibolite facies at 550–670°C and 0.52–0.65 GPa. These three stages define a clockwise P-T path with near-isothermal decompression and cooling following the peak high-pressure metamorphism. This suggests that the Amdo granulites underwent an initial subduction to a deep crustal level of ~50 km and then were rapidly exhumed to a shallow crustal level (~20 km). The formation of Amdo granulites is considered to result from the arc-continent collision between the Amdo basement and the Qiangtang terrane in the middle Jurassic, which is a crucial step to the tectonic evolution of the Tibetan Plateau.     

近断层地震下梁式桥考虑SSI效应的能力谱法

合理地选取215条典型近断层地震动记录,并根据我国桥梁抗震设计规范的场地标准进行分类后,统计了适用于我国桥梁抗震设计的近断层地震弹塑性加速度和位移反应谱,并拟合了阻尼比对近断层地震弹塑性反应谱的影响关系式,进而得到近断层地震的弹塑性需求谱. 再将其与FEMA440的考虑土-结构相互作用（SSI效应）的方法、Chopra改进能力谱法相结合,完善了近断层地震下适用于我国梁式桥且能考虑 SSI效应的能力谱法 . 最后,将本文方法应用于某梁式桥的抗震性能评估中,结果表明：对于近断层地震下考虑SSI效应的我国梁式桥,FEMA440的计算结果偏于保守,而本文方法的计算结果则较为合理,可以应用于我国梁式桥的抗震性能评估中.     

近断层地震动峰值加速度特性研究

在收集了世界范围内自由场地的近断层地震记录基础上,综合考虑台站场地和震级的差别,应用统计分析方法对近断层地震动的峰值加速度的衰减关系进行了研究,并与实际记录进行了比较,发现场地和震级的共同作用对近断层地震动的影响是显著的,为进一步的研究提供了参考.     

近断层地区抗震设计谱研究

预测近断层地区的抗震设计谱可以为该地区工程结构的抗震设计提供依据.通过对28条具有明显方向性效应特征的近断层地震动峰值速度、速度脉冲周期的统计分析,给出了估计近断层方向性效应脉冲地震动峰值速度和脉冲周期的经验关系式.对2种场地上脉冲地震动ATv/V的研究表明,岩石场地上的ATv/V值明显大于土层场地的ATv/V.基于近断层地震动的这一特征,建议了岩石和土层场地的等效脉冲地震动模型.基于脉冲地震动参数的经验关系式和简单的脉冲地震动模型给出了近断层地区岩石和土层场地上考虑方向性效应影响的设计谱.与规范设计谱的比较结果表明,我国设计谱的取值偏低,尚需考虑近断层脉冲型地震动的影响.     

Evidence against a chondritic Earth

The (142)Nd/(144)Nd ratio of the Earth is greater than the solar ratio as inferred from chondritic meteorites, which challenges a fundamental assumption of modern geochemistry--that the composition of the silicate Earth is 'chondritic', meaning that it has refractory element ratios identical to those found in chondrites. The popular explanation for this and other paradoxes of mantle geochemistry, a hidden layer deep in the mantle enriched in incompatible elements, is inconsistent with the heat flux carried by mantle plumes. Either the matter from which the Earth formed was not chondritic, or the Earth has lost matter by collisional erosion in the later stages of planet formation.     

常宁市灯坪地区铜铅锌成矿作用及其特征

灯坪地区铜铅锌矿化特征表明:其成矿地质作用具有"热液充填交代"、"氧化淋积—次生富集"、"动力变质分异"的明显特征,且热液充填交代成矿作用是本区最为主要的成矿作用.矿物及包裹体特征、碳氧同位素组成及矿脉与地层岩体微量、稀土元素对比值的相关分析表明,热液充填交代成矿作用中成矿物质主要来源于地层,热液水主要来源于大气降水,部分来源于地层和岩浆残余水.