中国大陆科学钻探孔区深层含金红石榴辉岩矿体     

杨文采杨午阳  程振炎 《岩石矿物学杂志》2005,24(5):457-463

利用大陆科学钻探岩心、岩心物性测定结果、测井与VSP资料来标定地震反射体,大大提高了中国大陆科学钻探孔区地质构造解释的可信度。岩石物性测定表明,金红石榴辉岩的纵波速度极高,会产生明显的反射与重力异常。数值模拟表明,孔区三维地震拱形反射主要是由榴辉岩及切穿它们的晚期破碎带共同形成的。在CCSD主孔东南方深部重力高部位有多个这样的拱形反射,预示在地表陡倾榴辉岩的延伸方向还有多个一定规模的隐伏榴辉岩体。  相似文献   

Reflection of P and SV waves from free surface of an elastic solid with generalized thermodiffusion   总被引：4，自引：0，他引：4  

Baljeet Singh 《Journal of Earth System Science》2005,114(2):159-168

The governing equations for generalized thermodiffusion in an elastic solid are solved. There exists three kinds of dilatational waves and a Shear Vertical (SV) wave in a two-dimensional model of the solid. The reflection phenomena of P and SV waves from free surface of an elastic solid with thermodiffusion is considered. The boundary conditions are solved to obtain a system of four non-homogeneous equations for reflection coefficients. These reflection coefficients are found to depend upon the angle of incidence of P and SV waves, thermodiffusion parameters and other material constants. The numerical values of modulus of the reflection coefficients are presented graphically for different values of thermodiffusion parameters. The dimensional velocities of various plane waves are also computed for different material constants.  相似文献   

Structure of the rift basins in the central Gulf of California: Kinematic implications for oblique rifting     

Manuel Aragn-Arreola  María Morandi  Arturo Martín-Barajas  Luis Delgado-Argote  Antonio Gonzlez-Fernndez 《Tectonophysics》2005,409(1-4):19-38

We use structural and seismostratigraphic interpretation of multichannel seismic reflection data to understand the structure and kinematic history of the central Gulf of California. Our analysis reveals that oblique strain in the central Gulf formed two tectono–sedimentary domains during distinct deformation stages. The eastern domain, offshore Sonora, is bounded by the East and West Pedro Nolasco faults that may constitute the southernmost segments of the Tiburón Fault System. Within this domain, the dip-slip Yaqui Fault controlled deposition of 3.9 km of sediments in the half-graben Yaqui Basin. The western domain, offshore Baja California, is bounded by the Guaymas Transform Fault, which controlled the accumulation of 1.45 km of sediments within a half-graben that formed the early Guaymas Basin. The tectono–sedimentary activity offshore Sonoran likely ranges from Late Miocene–Pliocene to Late Pliocene time, while activity in the Guaymas Basin commenced in Late Pliocene time. Extinction of the main faults offshore Sonora was nearly coeval to the initiation of the Guaymas Transform Fault. Our results suggest that oblique strain has been accommodated by strain partition since the onset of rifting in the central Gulf. The Guaymas Basin is now a nascent spreading center, but prior to this, it evolved as a half-graben controlled by the Guaymas Transform Fault; such drastic transition is not constrained, but likely occurred during the Pleistocene time and must be localized < 30 km north of the axial troughs. The faults within the central Gulf transpose the Miocene N–S oriented grabens of Basin and Range style preserved onshore in the conjugate rifted margins.  相似文献   

Adaptive traveltime tomography of densely sampled seismic data   总被引：1，自引：0，他引：1  

Immo Trinks  Satish C. Singh  Chris H. Chapman  Penny J. Barton  Miguel Bosch  Adam Cherrett 《Geophysical Journal International》2005,160(3):925-938

  相似文献   

Integrated seismic interpretation of the Carlsberg Fault zone, Copenhagen, Denmark   总被引：1，自引：0，他引：1  

Lars Nielsen  Hans Thybo  Mette I. Jørgensen 《Geophysical Journal International》2005,162(2):461-478

  相似文献   

Geological constraints on the evolution of the Angolan margin based on reflection and refraction seismic data (ZaïAngo project)     

Maryline Moulin  Daniel Aslanian  Jean-Louis Olivet  Isabelle Contrucci  Luis Matias  Louis Géli  Frauke Klingelhoefer  Hervé Nouzé  Jean-Pierre Réhault  Patrick Unternehr 《Geophysical Journal International》2005,162(3):793-810

  相似文献   

Crustal-scale seismic profiles across Taiwan and the western Philippine Sea   总被引：13，自引：2，他引：13  

Kirk McIntosh  Yosio Nakamura  T.-K. Wang  R.-C. Shih  Allen Chen  C.-S. Liu 《Tectonophysics》2005,401(1-2):23-54

We have used combined onshore and offshore wide-angle seismic data sets to model the velocity structure of the Taiwan arc–continent collision along three cross-island transects. Although Taiwan is well known as a collisional orogen, relatively few data have been collected that reveal the deeper structure resulting from this lithospheric-scale process. Our southern transect crosses the Hengchun Peninsula of southernmost Taiwan and demonstrates characteristics of incipient collision. Here, 11-km-thick, transitional crust of the Eurasian plate (EUP) subducts beneath a large, rapidly growing accretionary prism. This prism also overrides the N. Luzon forearc to the east as it grows. Just west of the arc axis there is an abrupt discontinuity in the forearc velocity structure. Because this break is accompanied by intense seismicity, we interpret that the forearc block is being detached from the N. Luzon arc and Philippine Sea plate (PSP) at this point. Our middle transect illustrates the structure of the developing collision. Steep and overturned velocity contours indicate probable large-scale thrust boundaries across the orogen. The leading edge of the coherent PSP appears to extend to beneath the east coast of Taiwan. Deformation of the PSP is largely limited to the remnant N. Luzon arc with no evidence of crustal thickening to the east in the Huatung basin. Our northern transect illustrates slab–continent collision—the continuing collision of the PSP and EUP as the PSP subducts. The collisional contact is below 20 km depths along this transect NE of Hualien. This transect shows elements of the transition from arc–continent collision to Ryukyu arc subduction. Both of our models across the Central Range suggest that the Paleozoic to Mesozoic basement rocks there may have been emplaced as thick, coherent thrust sheets. This suggests a process of partial continental subduction followed by intra-crustal detachment and buoyancy-aided exhumation. Although our models provide previously unknown structural information about the Taiwan orogen, our data do not define the deepest orogenic structure nor the structure of western Taiwan. Additional seismic (active and passive), geologic, and geodynamic modeling work must be done to fully define the structure, the active deformation zones, and the key geodynamic process of the Taiwan arc–continent collision.  相似文献   

Underestimation of scale lengths in stochastic fields and their seismic response: a quantification exercise     

Stefan Carpentier  Kabir Roy-Chowdhury 《Geophysical Journal International》2007,169(2):547-562

  相似文献   

青藏高原东北缘盆山结合部位深反射资料处理方法与初步地质认识   总被引：3，自引：0，他引：3  

王海燕高 锐马永生朱 铉李秋生李鹏武匡朝阳  卢占武 《中国地质》2007,34(1):142-148

盆山结合带地质条件复杂、地形起伏大,深地震反射资料具有信噪比低、各种干扰波严重以及速度横向变化大等特点。针对盆山结合部位深反射资料的特点,主要利用ProMAX处理系统对横跨若尔盖盆地和西秦岭造山带结合部位的二维深地震反射资料(简称SP04-2剖面)进行折射静校正、叠前去噪、地表一致性处理、人机交互速度分析、剩余静校正循环迭代处理、地表基准动校正叠加和叠后去噪处理等方法试验研究,形成一套适应盆山结合部位深地震反射资料的处理方法和流程,最终得到SP04-2叠加剖面。该剖面首次揭示出若尔盖盆地—西秦岭造山带盆山结合部位的岩石圈结构,为研究盆山深部接触关系提供了可靠的地震学依据。  相似文献   

变形监测中基于信号反射预计的GPS多路径误差减弱方法   总被引：1，自引：0，他引：1  

车伟  熊永良 《四川测绘》2007,30(1):7-10

多路径是高精度GPS变形监测的主要误差来源。本文在推导信号反射预计公式的基础上,提出了一种削弱GPS多路径误差影响的附加参数法。试验表明该方法能有效减弱GPS相位多路径误差的影响。  相似文献