西北太平洋地震层析剖面及地球动力学启示

具有较高分辨率的日本海沟-长白山-东乌珠穆沁旗的地震层析成像剖面,显示了太平洋板块俯冲板片的形貌特征和长白山、大兴安岭下方的岩石圈结构特征,表明太平洋板块以26°倾角俯冲到660 km之后明显下插,在其西侧伴有一显著低速的热上涌体,不存在俯冲板块继续向西深入的迹象.根据太平洋板块俯冲时间及俯冲作用引起岩浆活动的时间差,可认为中国东部中生代岩浆活动与太平洋板块俯冲无直接的成因联系.同时还强调地震层析剖面反映的是现存的深部结构,它可以保留某些中生代的岩石圈结构特征,据此可推测华北中生代岩浆的演化与大陆板块内软流圈上涌体的活动有关.     

中国大陆及邻区新生代以来的一种构造形式:右旋运动及效应

根据地貌、地震、压应力分布、地壳运动的GPS速度矢量、新生代沉积、新生代火山岩、古地磁、深部地幔结构等特征,论证中国大陆及邻区自新生代以来呈现整体右旋运动特征,动力可能源于全球旋转背景下欧亚印度板块的碰撞,随着印度板块与亚洲板块碰撞后岩石圈加厚,以及周缘走滑断裂释放应力,导致在40Ma左右中国大陆具有明显整体右旋运动特征;随着印度板块持续向北俯冲,25Ma之后中国大陆整体进入较明显的向右旋转时期,并延续至今;简要讨论了中国大陆自新生代以来呈现的右旋运动效应。     

中国陆域近10年地震时空分布统计特征

对中国陆域近10年4级以上地震震中的空间分布和季节分布特征进行了统计分析，从1994年1月到2005年2月间的4级以上地震，共计966次。近10年的地震空间分布与中国陆域历史地震分布基本吻合。中国陆域地震活动与印度板块、太平洋板块及欧亚板块间的相互作用有关，与前者相关的地震位于青藏高原及其外围地区；与后者密切的地震活动集中在中国陆域南海，尤其是台湾省。同时地震活动多围绕断块的周围分布。地震震中较集中地分布在活动断裂带附近、断裂带密集分布地带以及大构造区域的边界地带。地震年际活动的季节统计分析表明，地震高峰期集中出现在春季和秋季，各年地震活动波动性最大，地震距平曲线与地球自转速度变化曲线协同，地球自转速度的季节性变化是影响地震活动的基本因素之一。     

张广才岭岩石圈结构及盆岭构造

中新生代期间，太平洋板块向欧亚大陆下俯冲，而在中国大陆内部却以拉张作用为主，在此期间，华北板块以北中生代之前拼合的微板块群－黑龙江板块群，也遭受了强烈的伸展作用，形成盆岭相间分布的地貌格局，表明已进入了强烈的伸展作用阶段。通过地表地质和地球物理综合研究，详细论述了张广才岭地区的地壳和岩石圈结构，讨论了山岭与其两侧盆地之间的成因联系。在此基础上探讨了中国东部大陆边缘伸展作用的特点和大地构造意义。     

中国东部大陆内部中生代盆地分布特征与地球动力学背景探讨

在编制和分析中国东部大陆内部中生代盆地分布图的基础上,对中国东部大陆内部的松辽盆地,辽西盆地群,渤海湾地区盆地分布,规模等进行了对比,认为是由于地球动力学背景,岩石圈厚度等不同所致,并提出中国东部内部的大陆盆地动力学模式,即伊泽奈崎板块以不同角度的对欧亚板块的俯冲,同时认为华北板块与华南板块撞后期效应不容忽视。     

汶川地震的岩石圈深部结构与动力学背景

中国西部地区由于受到印度板块向北推移挤压,青藏高原强烈变形,高原内部及其边缘的活断层上经常发生强烈地震,是大陆内部最活跃的地震区.汶川8级地震就发生在青藏高原东缘的松潘一甘孜地块与扬子地块交界的龙门山主中央断裂带上.作者利用面波层析成像、跨龙门山的被动源地震观测、爆破地震剖面的结果对震源附近的岩石圈结构和动力学特征进行研究,发现松潘一甘孜地块与扬子地块的岩石圈结构与性质有重大差异.扬子地块岩石圈显示为高速、坚固和稳定特性,而松潘-甘孜地块为低速、软弱及易于破碎.在松潘-甘孜地块中,中地壳内普遍存在一个低速层,它是引起中上地亮推覆运动的滑脱层,龙门山的推覆构造就是上部地壳仰冲的结果.汶川地震震源深度为14 km,正好位于龙门山推覆体的映秀-北川主中央断裂带上.     

中国东部大陆地区岩石圈热结构特征

根据最新汇编的热流数据,对我国东部大陆地区岩石圈热结构进行了研究,编制出我国东部大陆地区大地热流图、中国东部大陆莫霍面温度图以及中国东部大陆"热”岩石圈厚度图.在此基础上,对我国东部岩石圈划分出5个\\"热-构造区”:华南、扬子、华北、西伯利亚和松辽.自南向北,它们冷、热相间,并具有各自独特的岩石圈热结构特征.从整体上来讲,我国东部地区热流变化范围大,在30～140mW/m2之间,均值为(61.9±14.8)mW/m2.莫霍面温度多在500～850℃之间,"热”岩石圈厚度多在60～100km左右,岩石圈热结构总体上属于"冷壳热幔”型.中国东部大陆地区岩石圈热结构特征明显受中、新生代不同的深部地球动力学过程所控制.     

横波分裂研究方法分析及中国大陆地区横波分裂的构造含义

利用中国国家台网2001?2005年的数据, 采用 SC1991 和 WS1998 的方法, 通过分析SKS和SKKS震相, 获得了中国大陆地区国家地震基准观测台的分裂参数。各台站的结果差异较大。西南部、南部、西北部分裂时间比华北及中西部的分裂时间要少。快方向与 GPS 速度场的一致性表明岩石圈与软流圈的耦合现象。快方向在板块会聚带平行于板块边界, 在走滑断层处平行于断层走向。这些都可能表明地壳与地幔的一致变形。讨论了时间窗的截取长度、射线分裂的可能性和快方向随后方位角的变化。     

内蒙古东北部及周边地区前中生代构造发展演化史

内蒙古东北部地处西伯利亚板块南缘,南与中朝板块相邻。元古代—古生代期间历经西伯利亚板块的向南增生、地体拼贴、“中东亚洋”关闭和西伯利亚－中朝板块的对接碰撞形成统一欧亚板块等一系列构造事件,形成规模巨大的兴安－内蒙古地槽褶皱系（大陆边缘造山带）。中新生代主要受欧亚板块和太平洋板块运动的影响,表现为陆内造山作用,形成三种性质不同的叠合盆地。     

试论滇西澜沧群蛇绿岩套形成的构造环境

蛇绿岩套主要是由基性、超基性的火山岩和深成岩组成的杂岩。鉴于蛇绿岩与大洋地壳和地慢上部物质组成的一致性,以及多分布于地槽区或相邻板块的接触带这一基本事实,因此多数研究者赞同蛇绿岩的洋壳假说。根据这一假说,蛇绿岩形成于洋中脊,后被转移到岩石圈板块会聚边缘的消亡带。     

Study on crustal, lithospheric and asthenospheric thickness beneath the Qinghai-Tibet Plateau and its adjacent areas

Based on the results of pure dispersions of Rayleigh wave tomography in the Qinghai-Tlbet Plateau and its adjacent areas, tsklng S wave velocities from previous linear inversion as the initial model, using the simulated annealing algorithm, a nonlinear simultaneous inversion has been carried out for S wave velocity and thickness of different layers, including the crust, the lithosphere and the asthenosphere. The results indicate： The crustal thickness shows strong correlation with geology structures sketched by the sutures and major faults. The crust is very thick in the Qinghal-Tibet Plateau, varying from 60 km to 80 kin. The Ilthospherlc thickness in the Qinghai-Tibet Plateau Is thinner （130-160 kin） than Its adjacent areas. And two blocks can be recognized, divided by an NNE strike boundary running between 90°E-92°E inside the plateau. Its asthenosphere is relatively thick, varies from 150 km to 230 kin, and the thickest area is located in the western Qiangtsng. India has a thinner crust （32-38 kin）, a thicker lithosphere of 190 km and a rather thin asthenosphere of only 60 kin. Sichuan and Tarlm basins have the crust thickness less than 50 kin. Their Iithospheres are thicker than the Qinghai-Tibet Plateau, and their asthenospheres are thinner. A discussion has been made on the character and formation mechanism of the typical crust-mantle transition zone in the western Qiangtsng block.     

山东地区地壳及上地幔结构研究

利用布设在山东省境内的宽频带流动地震观测台阵和国家地震局固定地震观测台站记录的地震数据, 应用接收函数和SKS波分裂方法, 研究山东地区的地壳与上地幔结构, 得到该区域的地壳厚度、地壳平均P波与S波的波速比以及SKS波分裂延迟的分布情况。结果表明, 山东地区地壳厚度范围为28~39 km; 胶南隆起的北段和南段以及鲁西隆起北侧济阳凹陷的地壳厚度小于32 km, 鲁西隆起下方的地壳比较厚。研究区 P波与S波的波速比主要分布在1.67~1.94之间, 鲁西隆起西南部和胶南隆起北段该比值小于1.75, 可能是由中上地壳增厚以及下地壳减薄和拆沉造成。鲁西隆起南北P波与S波的波速比差异反映地壳活动的差异。地幔物质的各向异性显示, 山东地区西部的地壳减薄和拆沉可能仍在进行。     

喜马拉雅碰撞造山作用与(超)大型矿集区的形成:科学问题与思考

青藏高原及邻区是中国唯一的一块具有世界规模级的成矿富集区 ,迄今所发现的大型、超大型矿床 /矿集区 ,在时间抑或空间上均与喜马拉雅碰撞造山作用有着密切的联系 ,反映了与喜马拉雅碰撞造山作用过程相伴随的青藏高原周边及内部岩石圈薄弱地带的壳幔置换过程、层圈交换作用、流体活动及其地球化学分馏过程 ,是控制大型、超大型矿床 /矿集区形成的主要因素。青藏高原成矿大陆动力学研究是阐明该区矿产资源分布规律和进一步发现大型、超大型矿床 (矿集区 )的科学基础     

Destruction geodynamics of the North China craton and its Paleoproterozoic plate tectonics

Much attention has been paid in the last two decades to the physical and chemical processes as well as temporal-spatial variations of the lithospheric mantle beneath the North China Craton. In order to provide insights into the geodynamics of this variation, it is necessary to thoroughly study the state and structure of the lithospheric crust and mantle of the North China Craton and its adjacent regions as an integrated unit. Based on the velocity structure of the crust and upper mantle constrained from seismological studies, this paper presents various available geophysical results regarding the lithosphere thickness, the nature of crust-mantle boundary, the upper mantle structure and deformation characteristics as well as their tectonic features and evolution systematics. Combined with the obtained data from petrology and geochemistry, a mantle flow model is proposed for the tectonic evolution of the North China Craton during the Mesozoic-Cenozoic. We suggest that subduction of the Pacific plate made the mantle underneath the eastern Asian continent unstable and able to flow faster. Such a regional mantle flow system would cause an elevation of melt/fluid content in the upper mantle of the North China Craton and the lithospheric softening, which, subsequently resulted in destruction of the North China Craton in different ways of delamination and thermal erosion in Yanshan, Taihang Mountains and the Tan-Lu Fault zone. Multiple lines of evidence recorded in the crust of the North China Craton, such as the amalgamation of the Archean eastern and western blocks, the subduction of Paleo-oceanic crust and Paleo-continental residue, indicate that the Earth in the Paleoproterozoic had already evolved into the plate tectonic system similar to the present plate tectonics.     

Post-collisional lithosphere delamination of the Dabie-Sulu orogen

The consistence between the first rapid cooling time (226-219 Ma) of the untrahigh pressure metamorphic (UHPM) rocks in the Dabie Mountains and the formation time (205-220 Ma) of the syncollisional granites in the Qinling and Sulu areas suggests that the first rapid cooling and uplift of the UHPM rocks may be related to breakoff of subducted plate. Therefore the second rapid cooling and uplift (180-170 Ma) of the UHPM racks needs a post-collisional lithosphere delamination which resulted in the granitic magmatism with an age of about 170 Ma. In addition, the rapid rising of the Dabie dome in the early Cretaceous (130-110 Ma) and the corresponding large-scale magmatism in the Dabie Mountains need another lithosphere delamination. The geochronology of the post-collis- ional mafic-ultramafic intrusions and geological relationship between the mafic-ultramafic intrusions and granites suggest that partial melting was initiated in the mantle, and then progressively developed in the crust, suggesting a mantle upwelling underneath the Dabie Mountains. The unusual fractional trend of the gabbros characterized by lower SiO2 content (46.24%) corresponding to lower MgO content (4.53%) and their typical geochemistry features of the lower crust suggest underplating of the mantle derived magma and interaction between the magma and lower crust before their intrusion. Lithosphere delamination could be the dynamic cause of the mantle upwelling and underplating. The seismic tomography results of the Dabie Mountains and adjacent areas clearly show lithosphere thinning below the north and south sides of the Dabie Mountains. Because there is no Cenozoic magma event in the Dabie Mountains, the lithosphere thinning may result from delamination of thickened lithosphere mantle after collision. In addition, both the lower velocity zone in the 40 km depth and the basin + dome + basin coupling relationship in the Dabie Mountains also suggest the lithosphere delamination and underplating on the two sides of the orogen.     

华南块体各向异性分区及上地幔动力学含义

利用SKS波分裂方法, 对布设在华南地区的宽频带流动地震观测台阵数据进行分析。研究结果表明, 华南块体(SCB)的SKS波分裂自西向东存在明显的变化。在华南块体西部克拉通岩石圈保留完整的四川盆地区域, SKS波分裂不明显, 反映该区域岩石圈厚且缺乏大规模的一致性变形; 在四川盆地东缘褶皱带区域, SKS波分裂快波方向主要为NNE向, 分裂延迟时间可以达到1 s左右, 记录了该区域岩石圈地幔经历的一致的显著变形; 华南块体东部的SKS波分裂快波方向主要为ENE向, 分裂延迟时间为1 s左右, 该区域各向异性主要来自软流圈流动的贡献, 与大地幔楔的流动方向契合; 四川盆地东缘以东200 km范围内, 各向异性结果大部分显示为Null值, 显示该区域在地质历史上可能发生过复杂的地球动力学过程。     

Growth and reworking of cratonic lithosphere

To study the thinning of cratonic lithosphere in North China has been the hot subject of basic research in the fields of solid earth science in China. This paper presents an overview on the formation and evolution of continental crust, and outlines the mechanisms of forming the lithospheric mantle. It is suggested that the thinning of cratonic lithosphere principally proceeds in two ways, one by subduction erosion （e.g., North China）, and the other by a combination of subduction erosion and underplating degistion （e.g., Yangtze）.     

Late Mesozoic metamorphic core complexes: new constraints on lithosphere thinning in North China

Metamorphic core complexes (mcc’s) are among the most prominent structural styles of lithosphere extension and thinning during late Mesozoic in North China. In this paper, the geometrical, kinematic and age characteristics of some of the mcc’s, e.g. Liaonan, Waziyu (Yiwulüshan), Yunmengshan, etc., are discussed. Some common characteristics, such as kinematic polarity, geometric asymmetry, occurrence over a time span, scattered and isolated distribution, and progressive development, can provide direct constraints on the regional lithosphere extension and thinning in North China, which does not favor the prevailing plume model，a general delamination model or extensional collapse of overthickened orogenic crust. We argue that several aspects, such as the kinematic polarity at depths during lithosphere extension, gradual break-up of lithosphere plate, relationship between magmatism and regional extension, and coeval activity of mcc’s and Tan Lu fault, should be taken into consideration when constructing a more reasonable model for lithosphere extension and thinning in North China.     

小陆拼接、多旋回、陆内构造──中国大陆石油地质三根基柱

中国范围内没有洲级古陆，一些小陆块围绕西伯利亚逐步拼合而成大陆。陆块及其间洋壳相继俯冲、碰撞，导致多旋回构造运动和海陆广泛沉积。最能体现中国特色的是后期俯冲碰撞，引发古缝合线重新活跃，板内岩石圈下部俯冲叠接，岩石圈中部拆离、滑脱、叠覆，盖层强烈褶皱和逆掩推覆。山脉上升、盆地下陷。中国东部燕山运动、西部喜马拉雅运动都达到全球陆内构造运动高峰。中国中、西部多期改造盆地和东部燕山期后新生盆地，将成为中国油气勘查的两大目标。     

灵山岛早白垩世构造应力解析及区域地质意义

通过对灵山岛野外地质考察及总结前人资料, 并利用节理、岩墙和褶皱等应力感应构造的测量分析, 得出研究区早白垩世可能存在四期构造作用: 莱阳期NW 向伸展形成近海盆地, 莱阳期末期NW 向挤压反转作用, 青山期NW 向伸展裂谷作用和早白垩世末期NW 向挤压反转。灵山岛早白垩世两期伸展作用可能是分别对华北地区增厚地壳或岩石圈重力垮塌和岩石圈拆沉的响应, 而两期挤压反转作用可能是研究区由伊泽奈崎板块NW 向俯冲消减向太平洋板块NW 向俯冲过渡的结果。